Academic literature on the topic 'Traffic load. Load effect. Dynamic amplification factor'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Traffic load. Load effect. Dynamic amplification factor.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Traffic load. Load effect. Dynamic amplification factor"
1
Paeglite, Ilze, Ainars Paeglitis, and Juris Smirnovs. "DYNAMIC AMPLIFICATION FACTOR FOR BRIDGES WITH SPAN LENGTH FROM 10 TO 35 METERS." Engineering Structures and Technologies 6, no. 4 (2015): 151–58. http://dx.doi.org/10.3846/2029882x.2014.996254.
Full textAbstract:
Heavy traffic on the bridge cause not only static effects, but also dynamic effects. These effects can be indicated by different dynamic parameters like – natural frequency, bridge logarithmical decrement, bridge acceleration and dynamic amplification factor (DAF). Dynamic amplification factor is the most widely used parameter, because it shows amplification of the static effects on the bridge structure. Results show that for bridges road surface condition is a very important factor. If road surface contains ice bumps or potholes then heavy traffic driving with low speed can decrease load carrying capacity of a bridge.
2
Savard, Marc, Marc-André Careau, and Alain Drouin. "Experimental study on the dynamic effects caused by vehicular traffic on a ferry boarding ramp." Canadian Journal of Civil Engineering 29, no. 1 (2002): 27–36. http://dx.doi.org/10.1139/l01-069.
Full textAbstract:
This article presents some of the results obtained during a load test conducted on a ferry boarding ramp operated by the Société des traversiers du Québec. The measurements highlight the sensitivity of these structures to the dynamic effects caused by two heavy vehicles. Since the dynamic behaviour of highway bridges is affected by parameters different from those that affect ferry boarding ramps, the article presents a reflection on the dynamic load allowance suitable for the evaluation or design of this latter type of structure.Key words: boarding ramp, bridge, dynamic amplification factor, design codes.
3
Ruiz, Manuel, Luis Ramírez, Fermín Navarrina, Mario Aymerich, and David López-Navarrete. "A Mathematical Model to Evaluate the Impact of the Maintenance Strategy on the Service Life of Flexible Pavements." Mathematical Problems in Engineering 2019 (May 30, 2019): 1–10. http://dx.doi.org/10.1155/2019/9480675.
Full textAbstract:
The structural failure of a flexible pavement occurs when the accumulated fatigue damage produced by all the vehicles that have passed over each section exceeds a certain threshold. For this reason, the service life of pavement can be predicted in terms of the damage caused by the passage of a single standard axle and the expected evolution of traffic intensity (measured in equivalent standard axles) over time. In turn, the damage caused by the passage of an axle depends on the vertical load exerted by the wheels on the pavement surface, as given by the technical standard in application, and the depths and mechanical characteristics of the layers that compose the pavement section. In all standards currently in application, the unevenness of the road surface is disregarded. Therefore, no dynamic effects are taken into consideration and the vertical load is simply given in terms of the static weight carried by the standard axle. However, it is obvious that the road profile deteriorates over time, and it has been shown that the increase in the pavement roughness, when considered, gives rise to important dynamic effects that may lead to a dramatic fall in the expected structural service life. In this paper, we present a mathematical formulation for the fatigue analysis of flexible pavements that includes the effects of dynamic axle loading. A pavement deterioration model simulates the sustained growth of the IRI (International Roughness Index) over time. Time is discretized in successive time steps. For each time step, a road surface generation model provides a profile that renders the adequate value of the IRI. A QHV (Quarter Heavy Vehicle) model provides the dynamic amplification function for the loads exerted on the road surface along a virtual ride. This function is conveniently averaged, what gives the value of the so-called effective dynamic load amplification factor (DLA); this is the ratio between the effective dynamic loading and the static loading at each time step. Finally, the damage caused by the passage of the standard axle can be evaluated in terms of the dynamic loading. The product of this damage times the number of equivalent standard axles gives the total fatigue damage produced in the time step. The accumulated fatigue damage at each moment is easily computed by just adding up the damage produced in all the previous time steps. The formulation has been implemented in the software DMSA (Dynamic & Maintenance Simulation App). This tool has been specifically developed for the evaluation of projects in applications for financing submitted to the European Investment Bank (EIB). DMSA allows for quantifying the expected structural service life of the pavement taking into account both the rise of the dynamic axle loads exerted by the traffic as the road profile deteriorates over time and the different preventive maintenance strategies to be taken into consideration.
4
JUNGES, P., R. C. A. PINTO, and L. F. FADEL MIGUEL. "B-WIM systems application on reinforced concrete bridge structural assessment and highway traffic characterization." Revista IBRACON de Estruturas e Materiais 10, no. 6 (2017): 1338–65. http://dx.doi.org/10.1590/s1983-41952017000600010.
Full textAbstract:
Abstract The vehicles that travel on Brazilian highways have changed a lot in the last decades, with an increase in the traffic load and in the amount of trucks. This fact is not exclusive to our country, so much that in order to assess the structural safety of bridges, there was a great development in bridge weigh-in-motion systems (B-WIM) the last decade, especially in developed countries. Moses, in 1979, was the first one to introduce the B-WIM concept. This work presents the results of a B-WIM system applied on a bridge over the Lambari river, located at BR 153 in Uruaçu (Goiás). The weigh-in-motion technique used is based on Moses' Algorithm and uses influence lines obtained direct from traffic. Traffic characterization of that particular highway, as well as the effects introduced in the bridge structure and the experimental dynamic amplification factor are also discussed. At the end it is concluded that the system used is capable of detecting, with good precision, the axle spacing and the gross vehicle weight shows errors inferior to 3% when compared with the gross weight acquired with static scale.
5
Yang, Jian Rong, Yu Bai, Xiao Dong Yang, and Yun Feng. "Dynamic Amplification Factor Measuring of T-Girder Bridges." Key Engineering Materials 540 (January 2013): 29–36. http://dx.doi.org/10.4028/www.scientific.net/kem.540.29.
Full textAbstract:
Field measurement was conducted on the evaluation of dynamic amplification factors (DAF) for four existing T-girder bridges. Both ambient vibration testing and vehicle impact testing were carried out on the bridges. Ambient vibration testing is relatively easier to conduct and can provide detailed vibrating information of the structure. However vehicle impact testing is indispensable to obtain the impact factor of the traffic load. The measured vibration frequencies matched well to those of calculated values. This means that the finite element model may enable good predictions of the actual behavior of the bridge. The measured DAF for these bridges located in the interval [1.05, 1.22].
6
Caprani, Colin C. "Lifetime Highway Bridge Traffic Load Effect from a Combination of Traffic States Allowing for Dynamic Amplification." Journal of Bridge Engineering 18, no. 9 (2013): 901–9. http://dx.doi.org/10.1061/(asce)be.1943-5592.0000427.
Full text
7
Ma, Haiying, Zhen Cao, Xuefei Shi, and Junyong Zhou. "Dynamic Amplification Factor of Shear Force on Bridge Columns under Impact Load." Shock and Vibration 2019 (March 10, 2019): 1–14. http://dx.doi.org/10.1155/2019/9483246.
Full textAbstract:
Shear failure is a common mode for bridge column collapse during a vehicle-column collision. In current design codes, an equivalent static load value is usually employed to specify the shear capacity of bridge columns subject to vehicle collisions. But how to consider the dynamic effect on bridge columns induced by impact load needs further research. The dynamic amplification factor (DAF) is generally used in the analysis and design to include the dynamic effect, which is usually determined using the equivalent single degree of freedom (SDOF) method. However, SDOF method neglects the effect of the higher-order modes, leading to big difference between the calculated results and the real induced forces. Therefore, a novel method to obtain dynamic response under concentrated impact load including the effect of higher-order modes is proposed in the paper, which is based on the modified Timoshenko beam theory (MTB) and the classical Timoshenko beam theory (CTB). Finite element models are conducted to validate the proposed method. The result comparisons show that the results from the proposed method have more accuracy compared with the results from the CTB theory. Additionally, the proposed method is employed to calculate the maximum DAF of shear forces for bridge columns under impact load. Parametric studies are conducted to investigate the effect on the DAF of shear forces including slenderness ratio, boundary condition, and shape and position of impact load. Finally, a simplified formula for calculating the maximum DAF of shear force is proposed for bridge column design.
8
Rattigan, Paraic H., Arturo González, and Eugene J. OBrien. "Influence of pre-existing vibrations on the dynamic response of medium span bridges." Canadian Journal of Civil Engineering 36, no. 1 (2009): 73–84. http://dx.doi.org/10.1139/l08-104.
Full textAbstract:
Critical static bridge loading scenarios are often expressed in terms of the number of vehicles that are present on the bridge at the time of occurrence of maximum lifetime load effect. For example, 1-truck, 2-truck, 3-truck, or 4-truck events usually govern the critical static loading cases in short and medium span bridges. However, the dynamic increment of load effect associated with these maximum static events may be assessed inaccurately if it is calculated in isolation of the rest of the traffic flow. In other words, a heavy vehicle preceding a critical loading case causes the bridge initial conditions of displacement and acceleration to be nonzero when the critical combination of traffic arrives on the bridge. Failure to consider these pre-existing vibrations will result in inaccurate estimation of dynamic amplification. This paper explores these dynamic effects and, using statistical analyses, outlines the relative importance of pre-existing vibrations in the assessment of total traffic load effects.
9
Li, Xin, Li Liang, and Fu Chun Wang. "Numerical Simulation of Vibration of Highway Cable-Stayed Bridge with Steel Arch Tower due to Moving Vehicle Loads." Advanced Materials Research 243-249 (May 2011): 1614–20. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.1614.
Full textAbstract:
Recently, with the development of highway traffic cause and long-span bridges, the vibration performances of highway bridges due to moving vehicle loads have attracted more and more attention. The vibration of a cable-stayed bridge with steel arch tower subjected to vehicle loads was studied in this paper. Firstly, the dynamic model of vehicle and finite element model of bridge were built and the dynamic differential equations of vehicle model and vehicle-bridge coupled system were derived. Then road roughness was simulated using superposition method of trigonometric series. Finally, the bridge responses caused by vehicle loads were calculated numerically. Furthermore, the effects of road roughness, vehicle velocity and bridge damping on bridge responses and their dynamic amplification factors were studied. The results and conclusions of present study are expected to be useful for the future revision of bridge design codes and maintenance and management of bridge.
10
Bui, Tuyen Van. "Effect of temperature and porosities on dynamic response of functionally graded beams carrying a moving load." Science and Technology Development Journal 20, K2 (2017): 24–33. http://dx.doi.org/10.32508/stdj.v20ik2.445.
Full textAbstract:
The effect of temperature and porosities on the dynamic response of functionally graded beams carrying a moving load is investigated. Uniform and nonlinear temperature distributions in the beam thickness are considered. The material properties are assumed to be temperature dependent and they are graded in the thickness direction by a power-law distribution. A modified rule of mixture, taking the porosities into consideration, is adopted to evaluate the effective material properties. Based on Euler-Bernoulli beam theory, equations of motion are derived and they are solved by a finite element formulation in combination with the Newmark method. Numerical results show that the dynamic amplification factor increases by the increase of the temperature rise and the porosity volume fraction. The increase of the dynamic amplification factor by the temperature rise is more significant by the uniform temperature rise and for the beam associated with a higher grading index.
Dissertations / Theses on the topic "Traffic load. Load effect. Dynamic amplification factor"
1
James, Gerard. "Analysis of traffic load effects an railway bridges." Doctoral thesis, KTH, Civil and Architectural Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3523.
Full textAbstract:
<p>The work presented in this thesis studies the load and loadeffects of traffic loads on railway bridges. The increasedknowledge of the traffic loads, simulated using fieldmeasurements of actual trains, are employed in a reliabilityanalysis in an attempt at upgrading existing railwaybridges.</p><p>The study utilises data from a weigh-in-motion site whichrecords, for each train, the train speed, the loads from eachaxle and the axle spacings. This data of actual trainconfigurations and axle loads are portrayed as moving forcesand then used in computer simulations of trains crossing twodimensional simply supported bridges at constant speed. Onlysingle track short to medium span bridges are considered in thethesis. The studied load effect is the moment at mid-span. Fromthe computer simulations the moment history at mid-span isobtained.</p><p>The load effects are analysed by two methods, the first isthe classical extreme value theory where the load effect ismodelled by the family of distributions called the generalisedextreme value distribution (GEV). The other method adopts thepeaks-over-threshold method (POT) where the limiting family ofdistributions for the heights to peaks-over-threshold is theGeneralised Pareto Distribution (GPD). The two models aregenerally found to be a good representation of the data.</p><p>The load effects modelled by either the GEV or the GPD arethen incorporated into a reliability analysis in order to studythe possibility of raising allowable axle loads on existingSwedish railway bridges. The results of the reliabilityanalysis show that they are sensitive to the estimation of theshape parameter of the GEV or the GPD.</p><p>While the study is limited to the case of the ultimate limitstate where the effects of fatigue are not accounted for, thefindings show that for the studied cases an increase inallowable axle load to 25 tonnes would be acceptable even forbridges built to the standards of 1940 and designed to LoadModel A of that standard. Even an increase to both 27.5 and 30tonnes appears to be possible for certain cases. It is alsoobserved that the short span bridges ofapproximately fourmetres are the most susceptible to a proposed increase inpermissible axle load.</p><p><b>Keywords:</b>bridge, rail, traffic load, load effect,dynamic amplification factor, extreme value theory,peaks-over-threshold, reliability theory, axle loads, fielddata.</p>
Book chapters on the topic "Traffic load. Load effect. Dynamic amplification factor"
1
Hekič, D., J. Kalin, A. Anžlin, M. Kreslin, A. Žnidarič, and G. Turk. "Experimental analysis of the dynamic amplification factor under traffic load." In Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations. CRC Press, 2021. http://dx.doi.org/10.1201/9780429279119-58.
Full textConference papers on the topic "Traffic load. Load effect. Dynamic amplification factor"
1
Lobo, John A., and David McCune. "Parametric Study of Influence of Structure Stiffness and Vehicle Characteristics on Dynamic Amplification." In 2016 Joint Rail Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/jrc2016-5717.
Full textAbstract:
This work presents the results of a parametric study on the dynamic amplification or impact factor due to transit vehicles. The study was performed on a single span simply supported bridge composed of prestressed concrete bulb tee girders with a concrete deck and direct fixation track. The study varied the key parameters affecting the structural response of the bridge, viz. stiffness of the bridge, vehicle speed and axle configuration. The bridge was numerically modeled using CSI-Bridge software. Stiffness was manipulated in the models by varying the elastic modulus of the concrete. Vehicle speed varied form quasi-static speed of 0.45 m/s (1 mph) to 35.32 m/s (79 mph) in increments of 1.34 m/s (3 mph). Different axle configurations were obtained by modeling trains consisting of different numbers of cars as well as considering different light rail vehicle types. Light rail vehicles defined by transit agencies in Denver, Boston, Washington DC, Phoenix and Houston were considered, which provided a total of 22 different configurations. Vehicle lengths as well the number of axles and spacing between axles varied. The moving loads were modeled using a linear elastic time history analysis. It was assumed that the rail was connected to the bridge deck at distinct points represented by the rail clip connections at approximately 0.76 m (30 inches) on-center. The magnitude of the axle load at a point ramped up from zero to maximum as the axle traveled from the preceding rail clip to the point under consideration and then decreased to zero as the axle traveled onto the following connection point. This triangular variation with time was modeled as a time dependent ramp function which was applied to the different light rail vehicle trains. The time between the start and end of the ramp function was dependent on the speed of the vehicles and train speed was modeled by changing the time base of the ramp function. Dynamic impact was estimated from the models from the ratio of the maximum deflection at midspan under time dependent moving load to the deflection due to a static load analysis. The results showed that the dynamic impact effects on the structure vary greatly with speed and configuration of the vehicle. While the effects generally increased with vehicle speed, the change was not linear and showed in general more than one peak value within the speed range selected. The maximum computed dynamic effect did not occur at the highest speed. The dynamic effect was also dependent on vehicle configuration, with a clear difference in responses between two axle and three axle cars. The overall length of the vehicle had less of an effect. The results were compared to the impact factors typically used by transit agencies and showed that in general for normal ranges of structure stiffness the Agency criteria are conservative or extremely close for vehicle speeds under 35.3 m/s (79 mph). However, the ACI equation for dynamic impact which is the only equation that incorporates vehicle speed and structural stiffness is usually conservative at higher speeds but may be unconservative at lower and medium speeds and does not reflect effects of axle configuration.
2
Ringsberg, Jonas W., André Liljegren, and Ola Lindahl. "Sloshing Impact Response in LNG Membrane Carriers: A Response Analysis of the Hull Structure Supporting the Membrane Tanks." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54067.
Full textAbstract:
This study presents the determination of structural response due to sloshing impact loads in LNG carriers with membrane type cargo tanks. These loads are characterized by very short durations and are thus likely to inflict a dynamic amplification in the response of the hull. Finite element analyses are presented using a model representing parts of an LNG membrane tank. The objective was to find and quantify the dynamic amplification factor (DAF) for the structural response towards sloshing impact pressures. The influence of variations in the load characteristics such as load duration, extent of the loaded area, load location as well as the influence of the insulation system was evaluated. The study shows that the response in the studied region of the hull structure experiences significant levels of dynamic amplification during impact loads with specific durations. The response sensitivity analysis also shows that the insulation system (MARK III type) has a large effect on the dynamic behaviour of the hull structure. It has been found to alter the magnitude of the stress and deflection response for key structural members. It also changes the load time durations for which the maximum dynamic amplification occurs and increases the magnitude of the corresponding response DAF. Finally, it has been found that dynamic response gives DAF values of up to 2. The effects have been found to be present for temporal load characteristics commonly occurring in sloshing model tests and full-scale measurements and are therefore likely to occur for a vessel in operation.
3
Datta, N., and J. D. Thekinen. "Wet Vibration of Axially Loaded Elastically Supported Plates to Moving Loads: Aircraft Landing on Floating Airports." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-10445.
Full textAbstract:
Dynamic analysis of thin rectangular elastically supported stiffened plates with axial loads is presented. A floating airport is modeled as a horizontal Kirchhoff’s plate, which is elastically supported at the ends; and is subjected to the impact of aircrafts landing and deceleration over its length. This sets the free-free-free-free plate into high-frequency vibration, causing flexural stress waves to travel over the plate. First, the beam natural frequencies and modeshapes in either direction are generated with these complexities. The Eigen value analysis of the governing differential equation is done, using the weighted summation of the product of the beam modes. The accuracy of the frequencies is compared with those from FEA studies. The radiation pressure on the bottom side of the plate is included to reduce the frequencies by the added-mass effect. The plate is then subjected to decelerating shock loads. The vibratory response is analyzed by the computationally efficient normal mode analysis. The amplification factor vs. the taxiing time of the moving load is generated.
4
Irwanto, B., J. Gier, D. Pawandenat, and H. J. Hardtke. "Modal Strain Analyses of a Radial Turbine." In ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/gt2003-38327.
Full textAbstract:
Strain measurement on blade and the calculation of blade stress during test are critical to determine the actual stress and the life of blades. Since the dynamic loads acting on blades, such as gas pressures and load changes during operation, might not be known, the concept of strain amplification factor (SAF) can be used to estimate the maximum strain/stress of blade during resonance. The SAF is defined as a ratio between the maximum modal strain on blade from FE analysis and the measured strain or computed strain of a particular place on blade. In this paper, this concept is reviewed and further analysis is carried out. To verify the theoretical analysis, the experimental tests of a radial turbine (blisk) are performed in detail. However, only experiments in static condition are considered in this work, since a better experimental condition can be achieved. Moreover, the verification of rotating blades could be accomplished with the similar procedure. The FE method is chosen as a tool to provide theoretical results. Two computations by using FE method are performed to obtain the SAFs. The first computation considers the use of sector model of turbine, which is usually practiced in industry. In the second calculation, the complete tuned turbine is taken into account. The obtained results for both computations and the effect of mistuning on SAF are discussed. Furthermore, the computed SAFs are compared to the experimental results.
5
Watts, Travis J., Jerry G. Rose, and Ethan J. Russell. "Relationships Between Wheel/Rail Surface Impact Loadings and Correspondingly Transmitted Tie/Ballast Impact Pressures for Revenue Train Operations." In 2018 Joint Rail Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/jrc2018-6184.
Full textAbstract:
A series of specially designed granular material pressure cells were precisely positioned directly below the rail at the tie/ballast interface to measure typical interfacial pressures exerted by revenue freight trains. These vertical pressures were compared to the recorded wheel/rail nominal and peak forces for the same trains traversing nearby mainline wheel impact load detectors (WILDs). The cells were imbedded within the bottom of new wood ties so that the surfaces of the pressure cells were even with the bottoms of the ties and the underlying ballast. The cells were inserted below consecutive rail seats of one rail to record pressures for a complete wheel rotation. The stability and tightness of the ballast support influenced the magnitudes and consistencies of the recorded ballast pressures. Considerable effort was required to provide consistent ballast conditions for the instrumented ties and adjacent undisturbed transition ties. Norfolk Southern (NS) crews surfaced and tamped through the test section and adjacent approach ties. This effort along with normal accruing train traffic subsequently resulted in reasonably consistent pressure measurements throughout the test section. The impact ratio (impact factor) and peak force values recorded by the WILDs compared favorably with the resulting magnitudes of the transferred pressures at the tie/ballast interface. High peak force and high impact ratio WILD readings indicate the presence of wheel imperfections that increase nominal forces at the rail/wheel interface. The resulting increased dynamic impact forces can contribute to higher degradation rates for the track component materials and more rapid degradation rates of the track geometry. The paper contains comparative WILD force measurements and tie/ballast interfacial pressure measurements for loaded and empty trains. Typical tie/ballast pressures for locomotives and loaded freight cars ranges from 20 to 30 psi (140 to 210 kPa) for smooth wheels producing negligible impacts. The effect of increased wheel/rail impacts and peak force values on the correspondingly transmitted pressures at the tie/ballast interface is significant, with increased pressures of several orders of magnitude compared to nominal impact forces from wheels.