Academic literature on the topic 'Dynamic loads of vibration acceleration'
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Journal articles on the topic "Dynamic loads of vibration acceleration"
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Zhang, Zhange, Wenbo Ji, Bowen Yang, Junzhou Huo, and Xuanxuan Li. "Dynamic analysis and vibration reduction of mechanical-hydraulic coupled tunnel boring machine (TBM) main drive system." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 236, no. 1 (2021): 115–25. http://dx.doi.org/10.1177/09544062211029330.
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Tunnel Boring Machine always works in the changeable geologies with multiple drivers, which leads to severe vibration of the TBM main drive system and key component failures. The vibration characteristics of TBM under different working conditions and the vibration reduction analysis have important meanings. First of all, by considering the time-varying random loads of the cutters, the contact force of the gears, the stiffness of the main bearing, and the stiffness of the cylinders, a mechanical-hydraulic coupling nonlinear dynamic model of the TBM main drive system was built according to the assembly relationship and load transmission path of the main drive system. Secondly, the dynamic model of the TBM main drive system is verified by comparing the theoretical vibration with the real vibration of the TBM main drive system. The error of the vibration acceleration is 10% to 30%. Three typical loads are defined under typical working conditions, and the vibrations of the TBM main drive system under three typical loads were analyzed. Finally, the sensitivity analysis of the cylinder damping shows that the damping at the position of the propulsion cylinder has a great influence on the vibration of the TBM main drive system. The results show that when the damping coefficient is 2.5 × 106 N·s/m, the maximum reduction of axial acceleration of cutterhead is 0.64 g, and that of the main beam front section is 0.55 g. The variable damping coefficient vibration reduction strategies under three typical loads are verified.
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Bulat, Anatolii, Mykola Lysytsia, Vladimir Lapin, et al. "Development and implementation of vibroseismic protection of buildings and structures from external dynamic loads." IOP Conference Series: Earth and Environmental Science 1348, no. 1 (2024): 012066. http://dx.doi.org/10.1088/1755-1315/1348/1/012066.
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Abstract The article considers the results of vibration dynamic tests of the vibration acceleration levels of a vibration insulated reinforced concrete slab and floors of a residential building, which have confirmed the effectiveness of the seismic vibration isolation system using rubber elements. The registered levels of vibration accelerations in residential premises on different floors do not exceed permissible levels according to sanitary standards, which ensures comfortable living conditions in the presence of dynamic influences. To determine the actual vibration levels of the soil and piles vibration and dynamic studies were carried out. Based on the results of these studies, numerical calculations were carried out to determine the compliance of the predicted vibration levels in residential premises with the existing sanitary standards when they are exposed to real anthropogenic loads.
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Bai, Wei, Kun Mu, Lingwei Kong, Wenbo Zhang, and Xiu Yue. "Dynamic Response and Its Frequency Domain Characteristics of Lateritic Soil Subgrade under Traffic Load during Construction." Advances in Civil Engineering 2020 (October 24, 2020): 1–12. http://dx.doi.org/10.1155/2020/8899482.
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Field tests were carried out on the compacted lateritic soil subgrade of Laibin-Mashan expressway in Guangxi Province to obtain the vertical vibration acceleration and dynamic stress amplitude of each test point under different axle loads and different driving speeds. The distribution law of the dynamic response and its frequency domain characteristics obtained by wavelet analysis emerged. The vibration of the subgrade is clearly aggravated by the increase of speed and load. Specifically, the acceleration of vehicle speed from 20 km/h to 40 km/h has a prominent effect on the vibration of subgrade, and the influence of speed on the vibration of subgrade decreases with subgrade depth. The acceleration has the greatest impact on the vibration energy in the third and fourth frequency bands.
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Yu, Dongyang, Jianfei He, Feihu Peng, et al. "Study on Vibration Characteristics of Paddy Power Chassis under Different Driving Conditions." Agriculture 13, no. 9 (2023): 1842. http://dx.doi.org/10.3390/agriculture13091842.
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To elucidate the vibrational characteristics of power chassis in paddy fields, we examined the Yanmar VPG6G rice transplanter across diverse terrains, including paddy fields, dry land, and concrete roads. Vibrational acceleration measurements, taken in longitudinal, transverse, and vertical orientations at key chassis locations, revealed noteworthy findings. The Mizuta power chassis exhibited its lowest root-mean-square (RMS) vibrational acceleration on concrete, while the highest was observed on paddy fields. The acceleration power spectra predominantly peaked between 1~14 Hz, with peak values amplifying as speed increased. Additionally, pendant orientation frequencies exceeded those of longitudinal and lateral directions. Both front and rear wheels mirrored the vibrational accelerations of the rear axle, but dynamic load coefficients for the front wheels consistently surpassed the rear, particularly at elevated speeds. This research not only enhances our understanding of terrain-induced vibrations and the intricate dynamics between terrain and tires but also lays the groundwork for designing optimized vibration-damping solutions tailored to prevalent road conditions.
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Sirotin, Pavel V., Aleksandr G. Sapegin, and Sergey V. Zlenko. "Experimental studies of ride quality of selfpropelled combine harvester." MATEC Web of Conferences 226 (2018): 01003. http://dx.doi.org/10.1051/matecconf/201822601003.
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The given work is devoted to the study of dynamic loads acting upon a combine harvester, which is one of the most vibration-loaded types of modern transport and technological machines. The results on the evaluation of dynamic loads and ride quality parameters of a self-propelled combine harvester when driving along gravel and bituminous surfaces under various operating conditions are presented based on complex experimental studies carried out with the help of tensor and vibrometry methods. The method and conditions of measurements are given. On the basis of the experimental studies, the acceleration spectrum on the main parts of the combine harvester are presented and their description is given. Using the methods of spectral analysis and statistical processing, a vibration modal analysis has been carried out during a combine harvester movement. According to the results of the analysis, the basic vibrational modes have been determined, and it has been shown that the self-propelled combine harvester movement dynamics is determined by vertical and longitudinal-angular vibrations of its core on pneumatic tires. Further scientific research directions to improve the ride quality and to decrease the dynamic loads on a considered class of self-propelled agricultural machines have been determined.
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Hawryszków, Paweł, Roberto Pimentel, Rafaela Silva, and Felipe Silva. "Vertical Vibrations of Footbridges Due to Group Loading: Effect of Pedestrian–Structure Interaction." Applied Sciences 11, no. 4 (2021): 1355. http://dx.doi.org/10.3390/app11041355.
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The vibration serviceability of footbridges has evolved from the adoption of a single pedestrian crossing in the resonance condition to load cases in which several pedestrians cross the structure simultaneously. However, in spite of this improvement, pedestrians continue to be considered as applied loads in codes of practice. Recent research has pointed out that modeling pedestrians as dynamic systems is a step further in the search for a more realistic design approach. This is explored in this paper, focusing on the case of vertical vibration. A two-span cable-stayed test structure was selected, and accelerations were measured from single and group crossings, both at the structure and at a pedestrian’s waist. Numerical simulations considering the pedestrians modeled as loads only and also as dynamic systems were implemented, and numerical and experimental time response vibration signatures were compared. Reductions of up to 25% and 20% in peak and RMS acceleration, respectively, were obtained when pedestrians were modeled as dynamic systems, in comparison with the less realistic model of pedestrians as loads only. Such reductions were shown to depend on the number of pedestrians involved in the group. The results, thus, highlight that pedestrian–structure interaction is an asset for the vibration serviceability design of footbridges.
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Gu, Zhanfei, Hailong Wei, Zhikui Liu, and Mingfei Zhang. "Dynamic Response Mechanism of Silt Ground under Vibration Load." Sustainability 14, no. 16 (2022): 10335. http://dx.doi.org/10.3390/su141610335.
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The frequent vibration loads during the operation of trains can cause vibration deformation of the tunnel structure and surrounding weak strata, thereby endangering the safe operation of trains. The purpose of this paper is to study the dynamic response of surrounding soil layers caused by train vibrations through the finite difference method with FLAC3D. Based on existing research, we studied the artificially deterministic exciting force function. Then, we simulated the tunnel working conditions of a train with a 3D model, and applied the artificially deterministic exciting force function to the tunnel model. To study the vibration caused by trains in silty soil, we divided the trains into two cases, one-way and two-way. We compared the displacement–time curves of one-way and two-way trains. When the horizontal distance between the monitoring point and the vibration source increases, the peak value of the displacement–time curve decreases. As the speed of the train increases, the peak value of the displacement–time curve increases. The vertical displacement of the ground under the dynamic load of the two-way train is greater than that of the one-way train. In the acceleration–time curve, there is a lag in the ground acceleration response. The faster the speed of the subway train, the greater the peak value of the acceleration–time curve. This study can provide a guide for the evaluation and prevention of ground vibration subsidence and uneven subsidence of strata in the silt area of the Yellow River Region.
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Zhang, Qishu, Wuming Leng, Junli Dong, and Fang Xu. "Dynamic Response Characteristics of Railway Subgrade Using a Newly-Developed Prestressed Reinforcement Structure: Case Study of a Model Test." Materials 15, no. 19 (2022): 6651. http://dx.doi.org/10.3390/ma15196651.
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Poor subgrade conditions usually induce various subgrade diseases in railways, leading to some adverse influences. An innovative technology that involves installing a prestressed reinforcement structure (PRS) that consists of steel bars and lateral pressure plates (LPP) for subgrade was introduced to improve its stress field and provide compulsive lateral deformation constraints for slope. In this study, an investigation into the dynamic acceleration responses of railway subgrade strengthened according to different PRS schemes was presented using a 1:5 scale model test, aiming to explore the effects of the axle load, the reinforcement pressure, and the loading cycles on the acceleration characteristics of the subgrade. The experimental results showed that (1) after pretension of the steel bar, prestress loss occurred due to the soil creep behavior and group anchor effect, so a moderate amount of over-tension in practices would be necessary; (2) a distinctive periodical behavior of subgrade subjected to the cyclic loads was observed, the horizontal accelerations were generally less than the vertical accelerations at the same measurement heights, and the vibration energy attenuated gradually from the shoulder to the toe along the slope; (3) in the short-term tests, the peak accelerations at all measurement points had a linear correlation with the axle load, and oppositely, it showed an approximately linear decrease with the increasing reinforcement pressure; And (4) in the long-term tests, to simulate the heavy haul wagon with a 35 t axle load, the variation in the effective acceleration with loading cycles under reinforcement pressure 100 kPa initially exhibited a decrease and subsequently tended to be stable, which is apparently less than that without reinforcement pressure. Consequently, it was demonstrated that the PRS itself and increasing reinforcement pressure can effectively mitigate the subgrade vibration, and provide an appropriate alternative to improve the dynamic performance of railway subgrade under the moving train loads.
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Sadeghi, Faraz, Ahmad Kueh, Ali Bagheri Fard, and Nasim Aghili. "Vibration Characteristics of Composite Footbridges under Various Human Running Loads." ISRN Civil Engineering 2013 (October 22, 2013): 1–8. http://dx.doi.org/10.1155/2013/817384.
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Various types of human running dynamic loads are numerically studied and compared to assess vibration characteristics of the light and slender composite footbridges. Running, which is a common human activity, has been categorized with respect to its intensity into jogging, normal running, and sprinting. To explore the footbridge’s performance, the vibration responses are investigated through a series of analyses in terms of the peak accelerations and displacements. In the model verification, the acquired first natural frequency of structure has shown good agreement with the value reported in the literature. The structural performance of the slender composite footbridge is then evaluated with regard to the serviceability requirement given by the current design standards. It is generally found that the maximum acceleration of the composite footbridge due to the excitation of one person running varies under different running types because of diversities in the velocity and the step frequency. Furthermore, it is shown that the investigated structure provides sufficient human comfort against vibrations for all the examined three types of running loads.
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Pang, Minyang, Yuefang Wang, and Jinyu Zhai. "Dynamic simulation analysis of aircraft engine planetary gear system." Advances in Computer and Engineering Technology Research 1, no. 4 (2024): 214. https://doi.org/10.61935/acetr.4.1.2024.p214.
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The Geared Turbofan (GTF) engine is used for aircraft propulsion with fan drive, characterized by its complex structure and operation in challenging environmental conditions. During its operation, variations in gear meshing and loads on the transmission shaft exacerbate vibration within the transmission system, leading to a decline in engine performance. This paper established three-dimensional solid models of the X-type aviation engine planetary gear system, input shaft, and output shaft, and employed ADAMS for multibody dynamics analysis, achieving simulation of engine operational vibrations. Modal and harmonic response analyses were conducted using ANSYS to observe and analyze critical parameters such as vibration displacement, vibration acceleration, gear meshing forces, modal resonance, and harmonic resonance, evaluating the impact of vibration amplitude, frequency, and their effects on system performance and longevity, providing guidance for vibration control and optimization of aviation engine systems.
Dissertations / Theses on the topic "Dynamic loads of vibration acceleration"
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De, Silva Sandun S. "Vibration characteristics of steel-deck composite floor systems under human excitation." Thesis, Queensland University of Technology, 2007. https://eprints.qut.edu.au/16538/1/Sandun_De_Silva_Thesis.pdf.
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Steel-deck composite floor systems are being increasingly used in high-rise building construction, especially in Australia, as they are economical and easy to construct.
These composite floor systems use high strength materials to achieve longer spans and are thus slender. As a result, they are vulnerable to vibration induced under service loads. These floors are normally designed using static methods which will not reveal the true behaviour and miss the dynamic amplifications resulting in inappropriate designs, which ultimately cause vibration and discomfort to occupants.
At present there is no adequate design guidance to address the vibration in these composite floors, due to a lack of research information, resulting in wasteful post event retrofits.
To address this gap in knowledge, a comprehensive research project is presented in this thesis, which investigated the dynamic performance of composite floors under various human induced loads. A popular type of composite floor system was selected for this investigation and subjected to load models representing different human activities. These load models have variable parameters such as load intensity, activity type (contact ratio), activity frequency and damping and are applied as pattern loads to capture the maximum responses in terms of deflections and accelerations.
Computer models calibrated against experimental results are used in the analysis to generate the required information. The dynamic responses of deflections and accelerations are compared with the serviceability deflection limits and human comfort levels (of accelerations) to assess these floor types.
This thesis also treats the use of visco-elastic (VE) dampers to mitigate excessive vibrations in steel-deck composite floors. VE damper properties have been presented and their performances in reducing the excessive vibrations have been assessed this thesis.
The results identified possible occupancies under different loading conditions that can be used in planning, design and evaluation. The findings can also be used to plan retrofitting measures in problematic floor systems.
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De, Silva Sandun S. "Vibration characteristics of steel-deck composite floor systems under human excitation." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16538/.
Full textAbstract:
Steel-deck composite floor systems are being increasingly used in high-rise building construction, especially in Australia, as they are economical and easy to construct.
These composite floor systems use high strength materials to achieve longer spans and are thus slender. As a result, they are vulnerable to vibration induced under service loads. These floors are normally designed using static methods which will not reveal the true behaviour and miss the dynamic amplifications resulting in inappropriate designs, which ultimately cause vibration and discomfort to occupants.
At present there is no adequate design guidance to address the vibration in these composite floors, due to a lack of research information, resulting in wasteful post event retrofits.
To address this gap in knowledge, a comprehensive research project is presented in this thesis, which investigated the dynamic performance of composite floors under various human induced loads. A popular type of composite floor system was selected for this investigation and subjected to load models representing different human activities. These load models have variable parameters such as load intensity, activity type (contact ratio), activity frequency and damping and are applied as pattern loads to capture the maximum responses in terms of deflections and accelerations.
Computer models calibrated against experimental results are used in the analysis to generate the required information. The dynamic responses of deflections and accelerations are compared with the serviceability deflection limits and human comfort levels (of accelerations) to assess these floor types.
This thesis also treats the use of visco-elastic (VE) dampers to mitigate excessive vibrations in steel-deck composite floors. VE damper properties have been presented and their performances in reducing the excessive vibrations have been assessed this thesis.
The results identified possible occupancies under different loading conditions that can be used in planning, design and evaluation. The findings can also be used to plan retrofitting measures in problematic floor systems.
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Södergren, Jones, and Anton Barraza. "Dynamic Assessment of Footbridges : A designer's method to estimate running induced vibrations." Thesis, KTH, Bro- och stålbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-229814.
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Dynamic problems in footbridges, such as sensible vibrations caused by human induced loading, has on a number of occasions been observed. These vibrations are rarely an ultimate limit state problem, but can be perceived as unpleasant by the pedestrian. In design guidelines there are propositions for how to asses the dynamic problem. However, they only take the walking load into account. It has been shown that, in the case of a running load, accelerations that lie above the comfort zone can occur and that running loads are more severe than walking loads in some cases. It is possible that the running load case has to be considered in future guidelines, and finding a feasible design methodology demands a lot of work. In this thesis, a method aimed to be easily used by a designer is analyzed. The amplitude of acceleration received as a result from a dynamic analysis in a commercial FEM software, was reduced by reduction factors to generate accelerations closer to reality. This could be identified and verified against recommendations.
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Muluka, Venu. "Optimal suspension damping and axle vibration absorber for reduction of dynamic tire loads." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0005/MQ39479.pdf.
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FAN, YINA, and FANGZHOU LIU. "Dynamic Analysis of Long Span Footbridges." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169183.
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A footbridge in Slussen is planned to be built and will connect the area of Gamla Stan with Sodermalm. As an increasing number of footbridges with large span tend to become more flexible and light these days, the corresponding dynamic problems due to decreased stiffness and mass draw much more attention. Specifically speaking, reduced stiffness and mass lead to smaller natural frequencies, which make the structure more sensitive to pedestrian-induced loading, especially in lateral direction. Fortunately, in this master thesis, only the vibration in vertical direction is focused due to that the footbridge in Slussen project uses enough lateral bracings to make sure that the safety of lateral vibration is kept at an acceptable level. In order to analyze dynamic response of the footbridge, the real footbridge structure is converted into a FE model by the commercial software LUSAS. In this thesis, four different kinds of critical standards are introduced, which are Sétra [8], Swedish standard Bro 2004 [9], ISO 10137 [5] and Eurocode respectively. By comparing these four criteria, Sétra and Eurocode are finally chosen to be the standard and guidelines for this project. They give the basic theories about how to model the pedestrian loading and provide critical values to check the accelerations in both vertical and lateral direction. By using FE software LUSAS, natural frequencies of the footbridge and the corresponding mode shapes can be calculated directly. Then, according to these results and relevant theories introduced by Sétra, the pedestrian loading can be modeled and the acceleration response of any specific mode can be obtained as well. Finally, based on the worst case with excessive acceleration, the methods to reduce dynamic response will be presented. Commonly, there are two ways to reduce acceleration response. One method is to increase the stiffness of the structure. However, the increased stiffness is always accompanied with increased mass of the structure. Because of this reason, the other way that installing dampers is widely used in recent years. In this thesis, the tuned mass dampers (TMDs) are introduced in detail as well as the information about the design principles of it. With important parameters known, TMDs can be added to the model to check how the accelerations can be reduced.
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Norouzi, Mahdi. "An Efficient Method to Assess Reliability under Dynamic Stochastic Loads." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1349496534.
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Arvidsson, Therese. "Train–Bridge Interaction : Literature Review and Parameter Screening." Licentiate thesis, KTH, Bro- och stålbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-144843.
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New railway lines are continuously being constructed and existing lines are upgraded. Hence, there is a need for research directed towards efficient design of the supporting structures. Increasingly advanced calculation methods can be motivated, especially in projects where huge savings can be obtained from verifying that existing structures can safely support increased axle loads and higher speeds. This thesis treats the dynamic response of bridges under freight and passenger train loads. The main focus is the idealisation of the train load and its implications for the evaluation of the vertical bridge deck acceleration. To ensure the running safety of train traffic at high speeds the European design codes set a limit on the vertical bridge deck acceleration. By considering the train–bridge interaction, that is, to model the train as rigid bodies on suspension units instead of constant moving forces, a reduction in bridge response can be obtained. The amount of reduction in bridge deck acceleration is typically between 5 and 20% for bridges with a span up to 30 m. The reduction can be higher for certain train–bridge systems and can be important also for bridge spans over 30 m. This thesis aims at clarifying for which system parameter combinations the effect of train–bridge interaction is important. To this end, a thorough literature survey has been performed on studies in train–track–bridge dynamics. The governing parameters in 2D train–bridge systems have been further studied through a parameter screening procedure. The two-level factorial methodology was applied to study the effect of parameter variations as well as the joint effect from simultaneous changes in several parameters. The effect of the choice of load model was thus set in relation to the effect of other parameter variations. The results show that resonance can arise from freight train traffic within realistic speed ranges (< 150 km/h). At these resonance peaks, the reduction in bridge response from a train–bridge interaction model can be considerable. From the screening of key parameters it can furthermore be concluded that the amount of reduction obtained with a train–bridge interaction model depends on several system parameters, both for freight and passenger train loads. In line with the European design code’s guidelines for dynamic assessment of bridges under passenger trains an additional amount of damping can be introduced as a simplified way of taking into account the reduction from train–bridge interaction. The amount of additional damping is today given as function of solely the bridge span length, which is a rough simplification. The work presented in this thesis supports the need for a refined definition of the additional damping.<br>Nya järnvägslinjer byggs kontinuerligt och befintliga linjer uppgraderas. Det finns därför ett behov av forskning inriktad på effektiv design av de bärande konstruktionerna. Alltmer avancerade beräkningsmetoder kan vara motiverade, särskilt i projekt där stora besparingar kan erhållas från att verifiera att befintliga konstruktioner kan bära ökade axellaster och högre hastigheter. Föreliggande avhandling behandlar broars dynamiska respons under belastning av gods- och passagerartåg. Huvudfokus är att studera modelleringsalternativ för tåglasten och vilka konsekvenser de har för utvärderingen av brobanans vertikala acceleration. För att garantera trafiksäkerhet vid höga tåghastigheter definierar de europeiska normerna en maximalt tillåten vertikal acceleration i brobanan. Genom att beakta tåg-bro-interaktion, där tågkomponenterna modelleras som avfjädrade stela kroppar istället för konstanta punktlaster, kan en minskning av brons respons erhållas. Reduktionen av brobanans acceleration är typiskt mellan 5 och 20% för broar med en spännvidd på upp till 30 m. Minskningen kan vara högre för vissa tåg-brosystem och kan vara viktigt också för spännvidder över 30 m. Denna avhandling syftar till att klargöra för vilka kombinationer av tåg-broparametrar effekten av tåg-bro-interaktion är viktig. I detta syfte har en omfattande litteraturstudie genomförts inom området tåg-spår-brodynamik. De styrande parametrarna i 2D tåg-brosystem har studerats vidare i en parameterstudie. Två-nivå faktorförsök har tillämpats för att studera effekten av parametervariationer samt den ytterligare effekten av samtidiga förändringar i flera parametrar. Effekten av valet av lastmodell sattes därmed i relation till effekten av andra parametervariationer. Resultaten visar att resonans kan uppstå från godstrafik inom ett realistiskt hastighetsintervall (< 150 km/h). Vid dessa resonanstoppar kan en betydande minskning av broresponsen erhållas med en tåg-bro-interaktionsmodell. Från studien av nyckelparametrar kan man vidare dra slutsatsen att reduktionen som erhålls med en tåg-bro-interaktionsmodell beror på flera systemparametrar, både för gods- och passargerartåg. Enligt de europeiska normernas rekommendationer för dynamisk kontroll av broar för passagerartrafik kan en ökad brodämpning introduceras som ett förenklat sätt att ta hänsyn till minskningen från tåg-bro-interaktion. Mängden tilläggsdämpning anges idag som en funktion av enbart brons spännvidd, vilket är en grov förenkling. Det arbete som presenteras i denna avhandling visar på behovet av en förbättrad definition av tilläggsdämpningen.<br><p>QC 20140429</p>
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Barrett, Anthony R. "Dynamic Testing of In-Situ Composite Floors and Evaluation of Vibration Serviceability Using the Finite Element Method." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28879.
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The presented research examined three areas: best practices in high quality dynamic testing of in-situ floor systems, extensive dynamic testing of three bare (non-fit out) in-situ multi-bay steel composite floors to estimate their dynamic parameters/response and to identify trends in dynamic behavior, and development of a set of fundamental finite element (FE) modeling techniques to adequately represent the dynamic response of steel composite floors for the purpose of evaluating vibration serviceability. The measurement, analysis, and computation of a floor's accelerance frequency response function (FRF) is the core premise linking all areas of the presented research.
The burst chirp signal using an electrodynamic shaker is recommended as the most accurate and consistent source of excitation for acquiring high quality measurements suitable for use in parameter estimation, operating deflection shape animation, and calibration/validation of FE models. A reduced mid-bay testing scheme is recommended as a time-saving alternative to modal testing over a full coverage area, provided the only desired estimated parameters are frequencies, damping, and mid-bay acceleration response.
Accelerance FRFs were measured with an electrodynamic shaker located within 23 unique bays on the three tested floors. Dominant frequencies ranged from 4.85 Hz to 9 Hz and measured estimates of damping varied considerably, ranging from 0.44% to 2.4% of critical (0.5%-1.15% was typical). Testing showed several mode shapes were localized to just a few bays and not all modes were adequately excited by forcing at a single location. The quality of the estimated mode shapes was significantly improved using multi-reference modal testing.
FE models for the tested floors were developed based on high quality measured data and were shown to provide adequate representations of measured floor behavior. Fundamental techniques are presented for modeling mass, stiffness, boundary conditions, and performing dynamic analysis. A method of evaluating vibration serviceability was proposed using the FE model's computed accelerance FRF for comparison with a design accelerance curve that represents an acceleration response threshold in the frequency domain. An example design accelerance curve is presented based on current serviceability guidelines for acceleration tolerance and effective harmonic forces due to human activities such as walking.<br>Ph. D.
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Senthilvasan, Jeevanandam. "Dynamic response of curved box girder bridges." Thesis, Queensland University of Technology, 1997.
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Oberhagemann, Jan [Verfasser], and Bettar O. el [Akademischer Betreuer] Moctar. "On Prediction of Wave-Induced Loads and Vibration of Ship Structures with Finite Volume Fluid Dynamic Methods / Jan Oberhagemann ; Betreuer: Bettar O. el Moctar." Duisburg, 2017. http://d-nb.info/1125371374/34.
Full textBooks on the topic "Dynamic loads of vibration acceleration"
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Kulisiewicz, Maciej. Modeling and identification of nonlinear mechanical systems under dynamic complex loads. Oficyna Wydawnicza Politechniki Wrocławskiej, 2005.
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L, Peterson Randall, Graham T. A, and Ames Research Center, eds. Simulated rotor test apparatus dynamic characteristics in the 80- by 120-foot wind tunnel. National Aeronautics and Space Administration, Ames Research Center, 1990.
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United States. National Aeronautics and Space Administration., ed. System identification of damped truss-like space structures. National Aeronautics and Space Administration, 1995.
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Center, Lewis Research, ed. SAMS acceleration measurements on Mir from January to May 1997 (NASA Increment 4). National Aeronautics and Space Administration, Lewis Research Center, 1998.
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DeLombard, Richard. SAMS acceleration measurements on Mir from January to May 1997 (NASA Increment 4). National Aeronautics and Space Administration, Lewis Research Center, 1998.
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Shukla, A. Dynamic failure of materials and structures / Arun Shukla, Guruswami Ravichandran, Yapa D.S. Rajapakse, editors,. Springer, 2010.
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Gherlone, Marco. Dynamic shape reconstruction of three-dimensional frame structures using the inverse finite element method. National Aeronautics and Space Administration, Langley Research Center, 2011.
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Buyal'skiy, Vladimir. Wind turbines with optimal control of electricity generation. INFRA-M Academic Publishing LLC., 2023. http://dx.doi.org/10.12737/1946200.
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In the monograph, based on the analysis of modern methods of automatic control of wind power installations, a solution is proposed for the correct connection (in theoretical terms) of related problems of dynamic behavior of power units with optimal control of electricity generation. In this direction, principles, structures and algorithms have been obtained to reduce the dynamic loads of the components of modern wind turbines based on timely preparation of the system for external disturbing influences and taking into account the vibration load of the drive under different operating modes of the power unit.
 It is intended for researchers and specialists in the field of wind energy, automation of technological processes, system analysis, as well as graduate students and students of relevant training areas and specialties of technical universities.
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Buyal'skiy, Vladimir. Efficiency of wind turbines in the Arctic and the Far North. INFRA-M Academic Publishing LLC., 2025. https://doi.org/10.12737/2163331.
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Based on the analysis of modern methods of automatic control of a wind farm, the monograph suggests a solution for the correct connection (in theoretical terms) of the problems of dynamic behavior of power units with optimal control of electricity generation and distribution to consumers in the Arctic and the Far North. In this direction, the principles, structures, mathematical models and algorithms have been obtained to reduce the dynamic loads of the components of modern wind turbines based on timely preparation of the system for external disturbances, consideration of the vibration load of the drive and the conditions of ice formation on the blades of the wind turbine, as well as improving the reliability of power supply based on the choice of an optimal management strategy, the status of the wind turbine process and the determination of the amount of electricity generated for each consumer. Theoretical methods and approaches can be useful for researchers and specialists in the field of wind energy, automation of technological processes, system analysis, as well as graduate students and students of relevant specialties of technical universities.
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Dynamics of the McDonnell Douglas large scale dynamic rig and dynamic calibration of the rotor balance. National Aeronautics and Space Administration, Ames Research Center, 1994.
Find full textBook chapters on the topic "Dynamic loads of vibration acceleration"
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Ni, Wenjun, and Chang Zhang. "Dynamic Simulation and Vibration Analysis of Rolling Bearing with Outer Ring Defects." In Lecture Notes in Mechanical Engineering. Springer Nature Singapore, 2025. https://doi.org/10.1007/978-981-97-7887-4_61.
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Abstract The statement is about establishing a finite element dynamic analysis model for a rolling bearing with a pit defect on its outer ring surface. Considering the influence factors such as load, speed, contact and friction, the dynamic response of the bearing outer ring surface with pit defects is studied. The shear stress when the ball enters and leave the defect and the vibration acceleration change between the rolling element and the outer ring are analyzed. Based on the shear stress distribution and vibration response information inside the structure, the fault mechanism of high-speed bearings can be further studied, which furnish a theoretical foundation for improving maintenance and management level for such equipment.
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Koçak, Eren, Caner Gençoğlu, Bülent Acar, and Kenan Gürses. "Estimating Applied Loads and Response Accelerations on a Dynamic System Using Vibration Data." In Topics in Modal Analysis & Testing, Volume 8. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-12684-1_20.
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Sun, Yu, Xuyang Cao, Yunbo Yuan, Guang Zhao, Song Ma, and Haofan Li. "Fault Simulation and Experimental Validation of Accessory Transmission System." In Lecture Notes in Mechanical Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-1876-4_31.
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AbstractAs an important part of the aero-engine, the accessory transmission system affects the operation status of the engine, and it is of great significance to carry out fault mechanism analysis and fault identification. This paper takes a certain type of aero-engine accessory transmission system as the research object, flexes the box using ANSYS, establishes a rigid-flexible coupling model under normal working conditions and fault conditions through ADAMS, and studies the vibration characteristics in single fault and multi-fault combination modes, such as unbalance of the shaft system, gear misalignment and gear broken tooth. Considering different load loading conditions, the dynamic simulation of the transmission system is carried out, the shafting displacement and box acceleration response are extracted, the time–frequency domain feature information of the vibration signal is analyzed, and the fault characteristics and fault types are corresponded one-to-one. The test bench for the principle prototype of the accessory transmission system is designed and built, and the experimental research is carried out. The results show that the simulation results have good consistency with the principle prototype test results, which verifies the rationality of the simulation model.
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Balendra, T. "Dynamic Effects of Winds on Buildings." In Vibration of Buildings to Wind and Earthquake Loads. Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2055-1_3.
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Zhou, Jie, Haowen Mou, Junchao Gao, and Xueping Chang. "Vibration and Stability Analysis of Functionally Gradient Flow Pipe with Axial Motion." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-4355-1_4.
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AbstractThe axially moving functionally graded pipe is widely used in many fields of industry, and its vibration and stability analysis is the key to its design. In this paper, the vibration characteristics and stability of functionally graded pipes with axial motion are analyzed. Based on the extended Hamilton variational principle, the dynamic equation of the pipe with internal flow velocity, material volume fraction index and axial velocity is established. The modified Galerkin method is used to solve the dynamic equation. The influence of the internal flow velocity, material volume fraction index, axial velocity and acceleration on the dynamic characteristics and stability of the system is analyzed. The characteristic curves of volume fraction index, axial velocity, acceleration and natural frequency are given. The results show that the natural frequency and critical velocity of the system increase with the increase of volume fraction index, and the designed volume fraction index can adjust the natural frequency of FGM pipeline system. When the system has axial acceleration, the greater the acceleration, the system will reach the critical value of axial instability in a short time.
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Kanno, Yoshihiro, and Izuru Takewaki. "Dynamic Steady-State Analysis of Structures under Uncertain Harmonic Loads via Semidefinite Program." In IUTAM Symposium on the Vibration Analysis of Structures with Uncertainties. Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0289-9_8.
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Li, Lin, Zhenzhong Wei, Yunan Jiang, et al. "Study on Dynamic Response of Gas Insulated Line Pipe Gallery Under Vehicle Traveling Loads." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-4355-1_27.
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AbstractThis study relies on the Huangbuling 500 kV transmission project to investigate the dynamic response law of gas insulated line (GIL) pipe gallery under vehicle traveling loads. A numerical model of GIL pipe gallery considering soil-structure interaction is developed using finite element software ABAQUS, and the effect of soil pressure on GIL is studied through static analysis. This study proposes a continuous step loading method for simulating vehicle traveling loads, and parametric analyses of different traveling directions and speeds are carried out to reveal the GIL’s dynamic response law in depth. The results show that the maximum stresses in the concrete and steel reinforcement cage of the GIL under soil pressure are located at the root of the right-side wall (both are less than the strength design value), and the maximum value of displacement is 6.556 cm occurs in the middle of the top plate. The maximum vertical acceleration, velocity and displacement responses under vehicle load occur at the top midpoint of the pipe gallery, while the maximum stress response occurs at the lower left corner. When heavy vehicle passes over the pipe gallery at different speeds, the peak acceleration, velocity and stress of the pipe gallery tends to increase with the increase of vehicle speed, while the peak displacement does not change significantly.
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Roeder, Alexander, Huiying Zhang, Lorenzo Sanchez, Yongchao Yang, Charles Farrar, and David Mascareñas. "Identification of Full-Field Dynamic Loads on Structures Using Computer Vision and Unsupervised Machine Learning." In Shock & Vibration, Aircraft/Aerospace, Energy Harvesting, Acoustics & Optics, Volume 9. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54735-0_5.
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Ma, Liying, Macheng Gui, Shaoxiong Gui, and Yuanwen Cao. "Analysis and Experiment Study About Vibration Compaction Based on Drucker-Prager Model." In Lecture Notes in Mechanical Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-1876-4_43.
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AbstractThe relationship and the applicable conditions between Mohr–Coulomb model and linear Drucker-Prager model were discussed, and the results showed that when the friction angle was less than 22° Drucker-Prager model was more suitable for modelling the soil unit; When the friction angle was more than 22°, the Mohr–Coulomb model should be used. In order to further study the compaction characteristics of vibratory roller and the dynamic relationship between vibratory roller and soil, the finite element model of “vibrating roller-soil” was established. The simulation results showed that vertical stress of the soil distributed symmetrically along the axial direction of the vibrating drum, shift forward along the direction of the vibration drum, and decreased sharply with the increasement of the depth. Then experiments carried out showed that acceleration of the vibrating drum was positively correlated with the compaction times, which verified the model was basically correct. Moreover, the regression equation between the compaction degree and the effective value of acceleration was obtained, which provided the idea for the new compaction degree monitoring system.
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Su, Juan, Guanghui Zhu, Wenjie Li, Jinchi Zhang, and Jingwei Su. "Research on Seismic Vibration Table Simulation of Large LNG Storage Tanks Based on Numerical Simulation." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-4355-1_30.
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AbstractIn order to study the dynamic characteristics and seismic performance of a large LNG storage tank, a finite element analysis model of the shaking table test model of a large LNG storage tank was established by using finite element calculation software with the background of 160,000 m3 LNG storage tank. The seismic response of the model structure was studied from the three directions of acceleration amplification factor, relative displacement and strain, and the seismic performance of the storage tank model under different seismic waves was obtained. The research results are of great significance for the study of dynamic characteristics and overall seismic performance of large LNG storage tanks.
Conference papers on the topic "Dynamic loads of vibration acceleration"
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Zhao, Wanqing, Jun Chen, Qian Ge, and Xiaolong Han. "Dynamic Testing and Serviceability Evaluation of Dance Induced Vibration in High Frequency Building Floor Systems." In IABSE Symposium, Tokyo 2025: Environmentally Friendly Technologies and Structures: Focusing on Sustainable Approaches. International Association for Bridge and Structural Engineering (IABSE), 2025. https://doi.org/10.2749/tokyo.2025.3241.
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<p>With the rise of mass fitness sports and the influence of modern pop culture, the number and size of dance venues in China's major cities are increasing. In this paper, a dance excitation vibration analysis and monitoring study is conducted for a building-covered venue to assess the vibration impacts of dance excitation on the high frequency floor structure. Firstly, the existing theoretical models of dance loads are investigated and summarized, and the selection principles of dancing load model parameters are discussed. This paper then suggests that both extreme value peak acceleration and root mean square peak acceleration be satisfied as vibration assessment criterion under dancing loads. The vibration testing of a high frequency stadium dance venue floor system is carried out by considering different dance rhythms as well as single, double and multiple dancers using accelerometers. The recorded data shows that the extreme value peak acceleration in certain dancing load cases are over the threshold, and the potential vibration mitigation measures are investigated.</p>
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Ruifu, Zhang, Wang Siyan, Chen Lihao, and Tao Qian. "Vibration control of beams under moving loads using grounded tuned mass inerter systems." In IABSE Symposium, Tokyo 2025: Environmentally Friendly Technologies and Structures: Focusing on Sustainable Approaches. International Association for Bridge and Structural Engineering (IABSE), 2025. https://doi.org/10.2749/tokyo.2025.2285.
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<p>The tuned mass inerter system (TMIS), which has been proven efficient for the moving-load-induced vibration control of beams, has better vibration absorption effect and less tuned mass than the tuned mass damper (TMD). This study proposes a grounded tuned mass inerter system (G-TMIS), consisting of a tuned spring, a mass, and a grounded inerter-based subsystem, which achieves higher space utilization and better vibration absorption performance. The application and optimization of G-TMISs for vibration suppression of multi-span beam under moving load series are investigated. Comparative analyses demonstrate that G-TMISs exhibit superior vibration mitigation compared to TMISs with equal tuned mass while requiring less overall weight to achieve identical structural performance demands. Additionally, vertical deflection and acceleration responses of the beam along with mitigated resonance reduce due to designed G-TMISs.</p>
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Hong, Hyung-Joo, Pavan Kumar Maddula, and Hyochan Jun. "Rough Road Vehicle Dynamics Analysis for Vehicle Vibration Assessment." In WCX SAE World Congress Experience. SAE International, 2025. https://doi.org/10.4271/2025-01-8306.
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<div class="section abstract"><div class="htmlview paragraph">This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model including non-linear tuning elements and flexible vehicle body is simulated on ride roads. The goal of the simulation is acceleration responses at the passenger locations in frequency domain. Body interface loads are recovered from the vehicle dynamic simulations. Frequency response function (FRF) of the body structure is ready in a fashion that input forces are applied to all body interface locations to the suspension and powertrains. This will give acceleration response sensitivity of the body structure to each body interface. The sum of body interface loads multiplied by FRF at each interface produces acceleration responses in frequency domain. A mid-size sedan model was used to demonstrate the process. A full vehicle dynamics model using Ansys Motion was simulated on a virtual ride road at a constant speed. The body loads were recovered in time domain and Fast Fourier Transformed (FFT) to convert them in frequency domain. The Body-In-white model was run a harmonic analysis to get body FRF. Python code was used to automate data communication and acceleration response calculation. The vehicle acceleration performance at the passenger locations is plotted in frequency domain. This process successfully demonstrated vehicle vibration performance at driver positions in terms of suspension tuning. It can make several design recommendations not available in the 100% vehicle dynamics approach, where the accelerations from the passenger locations are obtained from the same vehicle dynamics simulation. Not mentioning acceleration performance in frequency domain, it can pinpoint contributions of each load path from body interface points to the passenger locations. The contribution from each load path enables engineers to explore the design compromises: the most cost effective or the most timing effective design changes or both.</div></div>
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Wang, Frank Fan. "Comparing Shock, Random and Sine Vibration Loads of the Electronic Equipment." In ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73005.
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It is a challenge to correlate different dynamic loads. Often, attempts are made to compare the peak acceleration of sine wave to the root mean square (RMS) acceleration of random vibration and shock. However, peak sine acceleration is the maximum acceleration at one frequency. Random RMS is the square root of the area under a spectral density curve. These are not equivalent. This paper is to discuss a mathematical method to compare different kinds of dynamic damage at the resonant point of the related electronic equipment. The electronic equipment will vibrate at its resonance point when there are dynamic excitations. The alternative excitation at the resonant frequency causes the most damage. This paper uses this theory to develop a method to correlate different dynamic load conditions for electronic equipment. The theory is that if one kind of dynamic load causes the same levels of damaging effects as the other, the levels of vibration can then be related.
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Drobac, J., I. Štimac Grandić, and A. Bjelanović. "DLMs for Pedestrian Vibration Control on Bridges." In IABSE Symposium, Wroclaw 2020: Synergy of Culture and Civil Engineering – History and Challenges. International Association for Bridge and Structural Engineering (IABSE), 2020. http://dx.doi.org/10.2749/wroclaw.2020.0757.
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<p>The development of new materials and construction techniques enables engineers to build innovative structures, which become more and more slender and lighter. Light and slender footbridges are prone to vibrate when subjected to dynamic loads, especially to pedestrian dynamic loads. To build the structural model for checking the vibration serviceability of a footbridge, beside the footbridge properties, the designer need to know the loading models (dynamic load models - DLMs). This paper presents the review of DLMs for assessment of acceleration due pedestrian loading that designers can use to their advantage in bridge design.</p>
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Hassanpour Asl, P., H. Mehdigholi, and E. Esmailzadeh. "Vibration Analysis of Axially Loaded Bridges Traversed by Accelerating Vehicles With Passenger Dynamics." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58624.
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An investigation into the dynamics of vehicle-passenger-structure-induced vibration of suspension bridges traversed by accelerating vehicles is carried out. The vehicle including the driver and passengers is modeled as a half-car planer model with six degrees-of-freedom. In addition, the stiffness of compliant bushings at the connecting points of the shock absorbers to the body is considered. The bridge is assumed to obey the Timoshenko beam theory with axial load and arbitrary conventional boundary conditions. The roughness of the bridge is assumed as a differentiable function of location. Due to continuously moving the location of the variable loads on the bridge, and in the presence of damping force, the governing differential equations become complicated. The numerical simulations presented here are for the case of a vehicle traveling at a constant acceleration on a uniform bridge with rough surface and simply supported end conditions. The relationship between the bridge vibration characteristics, bridge roughness, and the vehicle speed and acceleration is rendered, which yields into search for a particular acceleration and speed that determines the maximum value of the dynamic deflection and the bending moment of the bridge. Results obtained from the Timoshenko beam theory are compared with those from the Euler-Bernoulli beam for which full agreements are found. Finally, the maximum deflection of the beam under moving loads is compared with that of the case with static loading.
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Kim, Tae Ho, Young Min Kim, Jongsung Lee, et al. "Duffing’s Vibration of a Rotor Supported on Gas Foil Bearings With Base Excitation: Measurements and Model Predictions." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56281.
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The widespread application of gas foil bearings (GFBs) to high-performance microturbomachinery requires accurate predictions for their physical models based on experimental test data. This paper presents the experimental measurements and model predictions of Duffing’s vibration in a rotor supported on GFBs with base excitation, implemented for small oil-free turbomachinery. The rotor consisted of an impeller at one end and a thrust collar at the other end. Two gas foil journal bearings (GFJBs) located between the impeller and thrust collar supported the rotor, and one pair of gas foil thrust bearings (GFTBs) supported the thrust collar. A series of dynamic excitation tests on the rotor-GFBs system was conducted with increasing dynamic load and excitation frequency, with the rotor operating at 20,000 rpm. An electromagnetic shaker provided dynamic sine sweep loads at excitation frequencies of 10–200 Hz to the test rig base in the axial and horizontal directions. An accelerometer installed on the test rig measured the acceleration due to the dynamic loads and provided it to the shaker controller for use as a reference signal. The acceleration level was controlled to ensure a constant value, while the excitation frequency increased. During the excitation tests, two sets of orthogonally positioned eddy current sensors and one axially positioned eddy current sensor recorded the rotor’s horizontal, vertical, and axial vibrations. The test measurements demonstrated that the rotor’s vibrational motions synchronous to the shaker excitation were the most dominant. At a constant dynamic load, as the excitation frequency increased, the amplitude of the rotor motion gradually increased until it reached a certain frequency, after which it jumped down at the higher frequencies. This amplitude jump-down phenomenon became more pronounced as the dynamic load increased. In general, both the peak amplitude and jump-down frequency increased nonlinearly with the increasing dynamic loads, thus revealing the typical Duffing’s vibration. For benchmarking against the test measurements, a previously developed numerical integration of a nonlinear equation of motion (EOM) was modified to predict the rotor’s vibrational motions with base excitations to an acceleration of 9 G (gravity). This nonlinear equation uses a third-order polynomial equation that best fits the measured structural foil bearing deflection versus static load. Comparisons of the predicted synchronous amplitude and acceleration of the rotor for the increasing excitation frequencies and the predicted waterfall plot of the amplitude of the rotor motion with the test measurements showed excellent agreements, thus validating the predictive model of the rotor-GFB system with base excitation.
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Kai, Satoru, and Akihito Otani. "Study on Dynamic Alternating Load on Piping Seismic Response." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45287.
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An inertia force resulting from excitation of a structure exposed to ground motion due to an earthquake excites the structure excited and generates a seismic force on the structure. The handling of seismic forces has been being discussed in terms of how the seismic force on a piping controls the deformation of the piping, load-controlled or displacement-controlled. A seismic design code for nuclear facilities applied in Japan qualifies this kind of seismic forces as primary stress components which shall be limited to prevent any plastic collapse, on the assumption that the seismic force mainly consists of load-controlled loads and the deformation due to earthquakes is caused by the loads. On the other hand, theoretically, an inertia force generated from response acceleration under harmonic vibration condition of a structure tends to oppose a response displacement of the structure. Since the inertia force produced from the response acceleration counteracts the response displacement, it is assumed that unstable failures represented by plastic collapse are hardly broken out on such a condition. To figure out the tendency between those forces, several time history analysis using simplified piping models, the vibration characteristic of which were arranged to have various specified natural frequency and specified damping ratio, were performed and the relationship between the element forces which result from response displacements and the inertia forces due to response accelerations have been investigated. The result of this investigation is expected to be useful to improve current seismic design methodology in the future.
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Zhang, Dayong, Qianjin Yue, Huihui Li, and Yanan Huang. "The Effects on Facilities and Crew Members of the Ice-Resistant Platforms Induced by Ice Vibrations in Bohai Sea." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83057.
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The current design and safety assessment of ice-resistance platforms have usually been considered the maximum bearing capacity under the extreme static ice loads. However, the effects on the facilities and crew members induced by the dynamic ice loads are not been considered, and the risks are greater than the structure security. So it is necessary to analyze the effect on the facilities and crew members by ice-induced vibrations. Based on the data monitored on the platforms in the Bohai Sea and the ISO standard about human body in vibration environment, human fatigue on the platforms is evaluated. The typical history curve of the deck acceleration is obtained and used to analyze the excitation of pipelines. A mechanical model of structural vibration of pipeline system is developed. With finite element modeling, the dynamic responses of the pipeline systems induced by deck vibration are calculated. The results show ice-induced vibration may have major effect on the crew members and the facilities, and this failure mode by strongly ice-induced accelerations should be considered in safety producing of the existing platforms and optimization design of the new platforms.
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Zhang, Sheng, Xiang Yuan Zheng, Xiangyu Zhang, et al. "Experimental Study on the Dynamic Responses of a Novel 10 MW Floating Offshore Wind Turbine Integrated With a Fish Cage." In ASME 2024 43rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2024. http://dx.doi.org/10.1115/omae2024-126028.
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Abstract This experimental work is to study the dynamic responses of a novel floating offshore wind turbine integrated with a fish cage (FOWT-FC) under wave and wind loads and to provide a benchmark for the establishment of numerical simulations. A series of model tests of scale 1:30 have been carried out in the ocean basin at Tsinghua Shenzhen International Graduate School (SIGS). This paper provides a detailed description of the experimental setup, including the design, fabrication, calibration and identification of the model, type and arrangement of the sensors. The 6 degrees of freedom (DOFs) displacements of cage, the accelerations at tower top and base and other responses are collected and analyzed. The displacement response amplitude operators (RAOs) are obtained through white noise wave tests, manifesting the excellent seakeeping performance of FOWT-FC. Besides, all responses in the operational and non-operational load cases are below the code limits. A group of controlled experiments are set up to investigate the effect of wind on dynamic responses, and several findings are discovered. In general, wind loads increase low-frequency responses, but have little effect on wave-frequency responses. Moreover, the low-frequency growths under turbulent wind are more significant than those under steady wind. Besides, the turbulent wind enhances the high-frequency responses at around tower’s 1st-mode vibration frequency. Whether under the action of random waves alone or combined wave-wind, the cage’s motions are predominantly controlled by low-frequency and wave-frequency responses, while hardly influenced by high-frequency excitations. The blades’ 3P excitation is not observed in the cage motion spectra, but found in the tower acceleration spectra. Also interestingly, the tower top acceleration has more pronounced spectral contents at high frequencies than the tower base acceleration does. On the contrary, the tower base acceleration has more pronounced spectral contents at low frequencies than the tower top acceleration does. These low frequencies are sourced from the wind loads and difference-frequency hydrodynamic loads.
Reports on the topic "Dynamic loads of vibration acceleration"
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Smalley, A. J., and P. J. Pantermuehl. TR-97-2 Foundation Guidelines. Pipeline Research Council International, Inc. (PRCI), 1997. http://dx.doi.org/10.55274/r0011730.
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These guidelines provide guidance to engineers responsible for installing or repamng the foundations of reciprocating compressors. If followed, the guidance should help assure an installation with a long life of trouble-free service. They address, in particular, mechanical integrity of the compressor/foundation installation, with emphasis on design of mounts, anchor bolts, and foundation block to carry the required dynamic loads. They defer to existing texts on vibration engineering for foundation blocks on their soil.
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Khosravifar, Arash. COMBINED EFFECTS OF LATERAL SPREADING AND SUPERSTRUCTURE INERTIA. Deep Foundations Institute, 2023. http://dx.doi.org/10.37308/cpf-2020-drsh-2.
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The seismic behavior of a RC pile with a diameter of 0.25 m subjected to liquefaction-induced lateral spreading was investigated using a shake table experiment that was conducted at the University of California, San Diego by Professor Ahmed Elgamal and Dr. Ahmed Ebeido (Ebeido and Elgamal 2019). A sinusoidal motion was applied at the base of a model that was inclined by 4 degrees. The loose and dense sand layers liquefied during the test, resulting in a permanent lateral spreading displacement of approximately 0.4 m (Figure E1). The pile was subjected to the combined effects of inertial loads from the acceleration of the superstructure mass and kinematic loads from the overlying nonliquefiable, dry crust. The dynamic responses of the soil and pile were analyzed to evaluate the relative contributions of inertial and kinematic loads during critical cycles (i.e., at the time of maximum inertia and the time of maximum pile strains). It was found that large pile strains developed after liquefaction was triggered. Large pile strains (and curvature) were recorded at a shallow depth within the crust (0.49 m) and a deeper location below the loose liquefiable sand (1.89 m). Large pile strains at shallow depth were found to be correlated with the inertial loads applied in the upslope direction. These upslope inertial loads were resisted by downslope crust loads, indicating an out-of-phase interaction. In contrast, large pile strains that occurred at deeper locations were correlated with downslope inertial loads and were accompanied by zero crust load, indicating that there was no lateral spreading force during the downslope inertial cycles. A gap at the downslope area in front of the pile formed because the soil displacements exceeded the pile displacements during the cyclic phase after liquefaction was triggered. The lack of crust load during the downslope inertial cycles is attributed to the pile head outrunning the crust displacement and causing the pile to be pushed into the gap at the downslope area in front of the pile. The interaction of inertia and kinematics appears to be a site- and project-specific phenomena. Therefore,the findings of this study—and, specifically, the lack of lateral spreading crust load during downslope inertial cycles—should be considered in design as one possible scenario in addition to the scenarios from several other studies that suggest combining the inertial loads with a lateral spreading force (e.g., Boulanger et al. 2007, Turner et al. 2016, Souri et al. 2022, Tokimatsu et al. 2005, Cubrinovski et al 2017).
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Moghimi, Gholamreza, and Nicos Makris. Response Modification of Structures with Supplemental Rotational Inertia. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, 2024. http://dx.doi.org/10.55461/tihv1701.
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Tall, multistory, buildings are becoming increasingly popular in large cities as a result of growing urbanization trends (United Nations Department of Economic and Social Affairs 2018). As cities continue to grow, many of them along the coasts of continents which are prone to natural hazards, the performance of tall, flexible buildings when subjected to natural hazards is a pressing issue with engineering relevance. The performance of structures when subjected to dynamic loads can be enhanced with various response modification strategies which have been traditionally achieved with added stiffness, flexibility, damping and strength (Kelly et al. 1972; Skinner et al. 1973, 1974; Clough and Penzien 1975; Zhang et al. 1989; Aiken 1990; Whittaker et al. 1991; Makris et al. 1993a,b; Skinner et al. 1993; Inaudi and Makris 1996; Kelly 1997; Soong and Dargush 1997; Constantinou et al. 1998; Makris and Chang 2000a; Chang and Makris 2000; Black et al. 2002, 2003; Symans et al. 2008; Sarlis et al. 2013; Tena-Colunga 1997). Together with the elastic spring that produces a force proportional to the relative displacement of its end-nodes and the viscous dashpot that produces a force proportional to the relative velocity of its end-nodes; the inerter produces a force proportional to the relative acceleration of its end-nodes and emerges as the third elementary mechanical element (in addition to the spring and dashpot) capable for modifying structural response. Accordingly, in this report we examine the seismic performance of multistory and seismically isolated structures when equipped with inerters. In view that the inerter emerges as the third elementary mechanical element for the synthesis of mechanical networks, in Chapter 2 we derive the basic frequency- and time-response functions of the inerter together with these of the two-parameter inertoelastic and inertoviscous mechanical networks. Chapter 3 examines the response of a two-degree-of-freedom (2DOF) structure where the first story is equipped with inerters. Both cases of a stiff and a compliant support of the inerters are examined. The case of two parallel clutching inerters is investigated and the study concludes that as the compliance of the frame that supports the inerters increases, the use of a single inerter offers more favorable response other than increasing the force transferred to the support frame. Chapter 4 examines the seismic response analysis of the classical two-degree-of-freedom isolated structure with supplemental rotational inertia (inerter) in its isolation system. The analysis shows that for the “critical” amount of rotational inertia which eliminates the participation of the second mode, the effect of this elimination is marginal on the structural response since the participation of the second mode is invariably small even when isolation systems without inerters are used. Our study, upon showing that the reaction force at the support of the inerter is appreciable, proceeds with a non-linear response analysis that implements a state-space formulation which accounts for the bilinear behavior of practical isolation system (single concave sliding bearings or lead-rubber bearings) in association with the compliance of the support of the inerter. Our study concludes that supplemental rotational inertia aggravates the displacement and acceleration response of the elastic superstructure and as a result, for larger isolation periods (Tb > 2.5s) the use of inerters in isolation systems is not recommended. Chapter 5 first examines the response analysis of a SDOF elastoplastic and bilinear structure and reveals that when the yielding structure is equipped with supplemental rotational inertia, the equal- displacement rule is valid starting from lower values of the pre-yielding period given that the presence of inerters lengthens the apparent pre-yielding period. The analysis concludes that sup- plemental rotational inertia emerges as an attractive response modification strategy for elastoplastic and bilinear SDOF structures with pre-yielding periods up to T1 = 1.5sec. For larger pre-yielding periods (say T1 > 2.0sec), the effectiveness of inerters to suppress the inelastic response of 2DOF yielding structures reduces; and for very flexible first stories; as in the case of isolated structures examined in chapter 4, the use of inerter at the first level (isolation system) is not recommended. Finally, chapter 6 shows that, in spite of the reduced role of inerters when placed at floor levels other than the first level (they no-longer suppress the induced ground acceleration nor they can eliminate the participation of higher modes), they still manifest a unique role since it is not possible to replace a structure with solitary inerters at higher levels with an equivalent traditional structure without inerters.
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DYNAMIC ANALYSIS OF LONG-SPAN TRANSMISSION TOWERLINE SYSTEM UNDER DOWNBURST. The Hong Kong Institute of Steel Construction, 2022. http://dx.doi.org/10.18057/icass2020.p.068.
Full textAbstract:
The extreme wind loads have caused enormous structural failures around the world, especially in high-rise flexible steel structures such as transmission towers. However, most of the design criteria discussed in the code are for extended pressure system (EPS). Due to the action of downburst, the structure may be damaged by the failure of local members, which may further lead to the collapse of transmission tower. In this paper, a long-span transmission tower-line system project with a span of 2500m and a main tower height of 272m is taken as the research object. The focus is on the dynamic response of suspension tower under the action of downburst. First, the simulation process of downburst wind field and the calculation criteria of wind load are introduced. Second, the whole tower-line system is simulated with refined finite element model, which includes two suspension towers, four anchor towers and other elements. The wind-induced vibration response of the structure is calculated by numerical simulation. Finally, the possible failure modes and bearing characteristics of the tower line system under downburst are obtained, which provides reference for engineering design.