Journal articles: 'Structural frames. Structural dynamics'

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Danish, Muhammad, Vinay Kumar Pingali, Somnath Chattopadhyaya, N. K. Singh, and A. K. Ray. "Idealisation and Formulation in Structural Dynamics Using Modal Analysis." Advanced Materials Research 418-420 (December 2011): 1022–25. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.1022.

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The crux feature of this paper is the equations of motion in a structural dynamics with respect to single reference frame that can be easily derived, and the results are well defined and converged. However, problem occurs, when the analysis of any complex, complicated structure is considered and its equation of motion is extracted with respect to single reference frame. The results are indecipherable, ambiguous and less converged. Thus, for such a complex structure, the results obtain with respect to multiple reference frames. In present study, an approximated model with a set of lumped masses, properly interconnected, along with discrete spring and damper elements are in consideration for continuous vibrating system. This results in dynamic equilibrium, which in turn results in formulation and idealization. As, rightly said by scientist Steve Lacy- “To me, there is spirit in a reed. It is a living thing, a weed, really and it does not contain spirit of sort. It’s really an ancient vibration”

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Miller, R. J. Dwayne, Ralph Ernstorfer, Maher Harb, Meng Gao, Christoph T. Hebeisen, Hubert Jean-Ruel, Cheng Lu, Gustavo Moriena, and German Sciaini. "`Making the molecular movie': first frames." Acta Crystallographica Section A Foundations of Crystallography 66, no. 2 (February 9, 2010): 137–56. http://dx.doi.org/10.1107/s0108767309053926.

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Recent advances in high-intensity electron and X-ray pulsed sources now make it possible to directly observe atomic motions as they occur in barrier-crossing processes. These rare events require the structural dynamics to be triggered by femtosecond excitation pulses that prepare the system above the barrier or access new potential energy surfaces that drive the structural changes. In general, the sampling process modifies the system such that the structural probes should ideally have sufficient intensity to fully resolve structures near the single-shot limit for a given time point. New developments in both source intensity and temporal characterization of the pulsed sampling mode have made it possible to make so-called `molecular movies',i.e.measure relative atomic motions faster than collisions can blur information on correlations. Strongly driven phase transitions from thermally propagated melting to optically modified potential energy surfaces leading to ballistic phase transitions and bond stiffening are given as examples of the new insights that can be gained from an atomic level perspective of structural dynamics. The most important impact will likely be made in the fields of chemistry and biology where the central unifying concept of the transition state will come under direct observation and enable a reduction of high-dimensional complex reaction surfaces to the key reactive modes, as long mastered by Mother Nature.

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Kim, Yeon Su, Sung Hyuk Park, Rag Gyo Jeong, and Tae Kon Lim. "Structural Safety Evaluations of Bogie Frames for Rubber-Tired AGT Vehichles." Key Engineering Materials 321-323 (October 2006): 1491–94. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1491.

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This study was aimed at evaluating the structural safety of the new bogie frames for Korean-standardized rubber-tired AGT vehicles. The guidance frame and the rotation frame were designed according to Korean-standardized specifications for rubber-tired AGT vehicles, and their stresses were analyzed by using the finite element method. Based on the results of the analysis, dynamic stresses were measured while the train was running under various conditions in the test track. Analytical and experimental results verified the structural safety of the new bogie frames.

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Liu, Jun, Pu Guo Gui, Jian Mei Wang, Yang Yu, and Zheng Hu Zhong. "Structure Optimization of the Aluminum Alloy Frames of Flight Simulator." Key Engineering Materials 667 (October 2015): 582–87. http://dx.doi.org/10.4028/www.scientific.net/kem.667.582.

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Frames are the main components of the flight motion simulator, which are the support for each shaft system, at the same time the rotating load for the external shaft, so the stiffness and dynamic characteristics of the frames in a large extent determines the final accuracy and dynamic performance of the flight motion simulator. For the cast aluminum alloy ZL114A frames of a 3-DOF flight motion simulator, using finite element analysis method, the dynamic characteristics are calculated and analyzed, and then the each order resonance frequency and mode of vibration are obtained. By using of the modal synthesis method and optimization algorithms, the structural dynamics of frames are designed optimally, so as to further reducing the moment of inertia, and improving the stiffness and dynamic characteristics of frames. This method has provided important reference for the reasonable design of the frame structure, and definitively established the foundation to further study the triaxial coupling dynamic characteristics and system mechanical optimization for the flight motion simulator.

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Yanao, Tomohiro, and Kazuo Takatsuka. "Kinematic effects associated with molecular frames in structural isomerization dynamics of clusters." Journal of Chemical Physics 120, no. 19 (May 15, 2004): 8924–36. http://dx.doi.org/10.1063/1.1698616.

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Park, Seon-Chee, Won-Kee Hong, Sunkuk Kim, and Xiangyu Wang. "Mathematical Model of Hybrid Precast Gravity Frames for Smart Construction and Engineering." Mathematical Problems in Engineering 2014 (2014): 1–14. http://dx.doi.org/10.1155/2014/916951.

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The structural stability, constructability, economic feasibility, environmental-friendliness, and energy efficiency of hybrid composite frame systems have been demonstrated by practical application and research. A hybrid composite frame system combines the economy of precast concrete structures with the constructability of steel frame structures, including erection speed. Novel composite frames will ultimately maximize the efficiency of structural design and facilitate construction. This paper presents hybrid precast frames, which are precast composite frames based on a simple connection between precast concrete columns and beams. The hybrid precast frames designed to resist gravity loading consist of PC columns, PC beams, and steel inserted in the precast members. Steel sections located between the precast columns were simply connected to steel inserted at each end of the precast beams. Dynamic analysis of a 15-story building designed with the proposed composite frame was performed to determine the dynamic characteristics of a building constructed of hybrid frames, including frequencies and mode shapes.

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Filiatrault, A., and S. Cherry. "Efficient numerical modelling for the design of friction damped braced steel plane frames." Canadian Journal of Civil Engineering 16, no. 3 (June 1, 1989): 211–18. http://dx.doi.org/10.1139/l89-046.

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A novel friction damping system for the aseismic design of framed buildings has been proposed by Canadian researchers. The system has been shown experimentally to perform very well and is an exciting development in earthquake resistant design.The design of a building equipped with the friction damping system is achieved by determining the optimum slip load distribution to minimize structural response. The optimum slip load distribution is usually determined using the general nonlinear dynamic computer program DRAIN-2D, which requires extensive computer time and is not practical for most design offices.This paper describes a new, efficient, numerical modelling approach for the design of friction damped braced frames. The hysteretic properties of the friction devices are derived theoretically and included in a friction damped braced frame analysis program, which is adaptable to a microcomputer environment. The optimum slip load distribution is determined by minimizing a relative performance index derived from energy concepts. The new numerical approach is much more economical to use than DRAIN-2D and is of great value for the practical design of friction damped braced frames. Key words: braced frames, brake lining, performance index, damping, dynamics, earthquakes, energy, friction.

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Dawe, J. L., A. B. Schriver, and C. Sofocleous. "Masonry infilled steel frames subjected to dynamic load." Canadian Journal of Civil Engineering 16, no. 6 (December 1, 1989): 877–85. http://dx.doi.org/10.1139/l89-130.

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Experimentally determined dynamic responses of ten scale models of masonry infilled steel frames were compared with the results of three simple analytical models. Effects investigated included stiffening and strengthening contribution of the masonry infill, degradation of the system, motion intensity, frame stiffness, and rotational joint rigidity at slab-to-column intersections. Tests on one-third scale models, subjected to sinusoidal motions, revealed that masonry infill markedly increases the dynamic strength and stiffness of the system. At weak-to-moderate motions (below 0.5 g), models exhibited a nonlinear response before the final failure, while strong motions accelerated the system degradation rate. Stiffer frames and rotationally rigid joints resulted in significantly increased system dynamic strength. A braced frame model wherein cross-bracing replaces the panel action adequately predicted linear and lower-region nonlinear responses of infilled frames with flexible column-to-slab rotational conditions. Satisfactory predictions of the linear response of framed walls with rigid column-to-slab rotational conditions were made with a single degree of freedom model. The third analytical model based on an equivalent strut technique was found to be unsatisfactory for predicting dynamic response of masonry infilled frames. Key words: masonry panel, steel frame, shear, dynamic, analytical, experimental.

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Baktash, Parvaneh, and Cedric Marsh. "Damped moment-resistant braced frames: a comparative study." Canadian Journal of Civil Engineering 14, no. 3 (June 1, 1987): 342–46. http://dx.doi.org/10.1139/l87-054.

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This paper reports a study on the comparisons between the behaviours of braced steel building frames with friction joints and with eccentric bracing, under seismic forces. Nonlinear time-history dynamic analysis is used. Friction damping is shown to be of particular merit. Key words: bracing, damping, ductility, dynamics, earthquakes, eccentric; energy dissipation, friction, hysteresis loops, response, steel frames, time history.

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ASTRAUSKAS, Tadas, and Michail SAMOFALOV. "Investigation of Complex Structural Designing of Mobile Facilities for Shipbuilding in Lithuanian Sea Region." Mechanics 27, no. 3 (June 10, 2021): 237–43. http://dx.doi.org/10.5755/j02.mech.28740.

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In the paper, it is proposed to cover by a mobile moving facility the shipyard open site, in Klaipeda, Lithuania (the EU). The facility of 40 m span consists of transversal frames, which are arranged by the step of 6.0 m, and a system of braces. Two types of steel frames have been considered: trussed and continuous. The actions are specified according to the design codes (Eurocode 3) and climatological data. In dynamic analysis, the longitudinal direction is defined for an inertia action, simulating braking. For calculating, a special algorithm of three stages has been prepared. At the first stage, three calculation schemes of one transversal frame were created. For the proposed schemes of the mobile moving facility, the calculation of only a transversal frame is effective in the preliminary determination of the cross-sectional areas and of the total structural weight. At the second stage, the frames were joined by braces. A preliminary comparison of the calculation results of the models was carried out after the first and second stages of the analysis. At the third stage, the dynamic analysis was performed and the influence of the dynamic impact was estimated. Finally, we compared the calculation results of three different FEM models and chose the most appropriate one. To sum up the investigations, conclusions and recommendations are presented.

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11

Leung, A. Y. T. "Exact dynamic stiffness for axial-torsional buckling of structural frames." Thin-Walled Structures 46, no. 1 (January 2008): 1–10. http://dx.doi.org/10.1016/j.tws.2007.08.012.

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Singh, M. P., M. Z. Elbadawy, and S. S. Bisht. "Dynamic strain response measurement-based damage identification in structural frames." Structural Control and Health Monitoring 25, no. 7 (April 17, 2018): e2181. http://dx.doi.org/10.1002/stc.2181.

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13

Song, Baoxi, Dongsheng Du, Weiwei Li, Shuguang Wang, Yue Wang, and Decheng Feng. "Analytical Investigation of the Differences between Cast-In-Situ and Precast Beam-Column Connections under Seismic Actions." Applied Sciences 10, no. 22 (November 22, 2020): 8280. http://dx.doi.org/10.3390/app10228280.

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At present, the engineering designers generally design and analyze the precast structural models according to the equivalent cast-in-situ principle, and have a vague understanding of non-identical problems. However, these issues cannot be ignored, especially for high-intensity areas. This paper considers the differences of the hysteretic relationship between two typical precast joints and cast-in-situ (RC) joints, and researches the influence of these differences on the seismic response of frame structures. For the monolithic precast joint, the force mechanism was analyzed based on its assembly form, and the differences with the RC joint in the testing phenomena were explained accordingly. The dimensionless hysteresis models of two types of joints were proposed, and the rationality of the monolithic precast joint model was verified according to the existing experimental results. Different performances of joints were realized by assigning the constitutive models calculated from sectional reinforcement to the spring elements of analysis models. Considering two possible performance deficiencies of each type of precast joint separately, a total of seven structural analysis models were formed. Nonlinear static analysis and dynamic time-history analysis methods were adopted to reveal the differences between precast frames and the RC frame in terms of structural capacity curve, displacement response, ductility demands of components and structural residual deformation. The results showed that under strong seismic excitation, the response differences between precast frames and the RC frame were significant, so it is worthwhile to establish nonlinear models suitable for precast frames in seismic analysis. This study is valuable for understanding and distinguishing the nonlinear response of precast frames and traditional RC frames.

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Xu, Zhi Jun, and Zeng Xin Yu. "Kinetic Analysis of Hydraulic Mount of Vehicular Engine Based on Fluid-Structure Interaction." Applied Mechanics and Materials 117-119 (October 2011): 279–82. http://dx.doi.org/10.4028/www.scientific.net/amm.117-119.279.

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A fluid-solid interaction FEM of entire hydraulic mount of vehicular engine are presented. The dynamic response of the hydraulic mount is simulated. By means of the simulated result of the mount transient response in time domain, the dynamic performance and transmissibility of the hydraulic mounts are calculated. the ALE method transforming reference frames is used to resolve the problem the reference frame of hydro-dynamical questions is different from the reference frame of structural questions.

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Omprakash Reddy, N., and A. Manchalwar. "Performance of 2-D Frame Equipped With Base isolation System under Dynamic Loadings." E3S Web of Conferences 184 (2020): 01099. http://dx.doi.org/10.1051/e3sconf/202018401099.

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Building responses have become a major concern in design research. Passive control techniques are implemented to improve structure efficiency. The present research aims to assess the efficiency of base isolation system for a 2D frame and to enhance the performance of structures that are subjected to seismic ground excitations and ground vibrations induced by blast. Two moments of resistant RC frames were studied and output of the isolator (Lead / Rubber Bearing) was observed to reduce structural responses. In SAP2000 non-linear dynamic analysis is conducted to compare normal and irregular moment-resistant frames and structural responses with and without passive control techniques. Isolators are constructed based on time of isolation. Reduction of structural responses is assessed by passive control techniques, and comparative analysis is performed. Mitigating systemic retaliation is affected by the implementation of passive control system.

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Kodur, V. K. R., M. A. Erki, and J. H. P. Quenneville. "Seismic design and analysis of masonry-infilled frames." Canadian Journal of Civil Engineering 22, no. 3 (June 1, 1995): 576–87. http://dx.doi.org/10.1139/l95-066.

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A simple analytical procedure, which can be used by practicing engineers, for the seismic design of masonry-infilled frames is presented. The analysis procedure, based on the experimental and analytical studies reported in the literature, accounts for the effect of infills in all three stages, namely, in computing seismic loading, in predicting response of the infilled frame, and in determining the strength of the infilled frame. Seismic loading is computed using the dynamic properties of the structure rather than arbitrary empirical relationships as recommended in design codes. Recommendations regarding the choice of infilled frame idealization, structural damping ratio, earthquake design spectrum, structural irregularity, and computational aids are made. Practical guidelines, which can be implemented during the construction phase and which have beneficial effects on the behaviour of infilled frames, are provided. Application of the proposed analytical procedure in a design situation is demonstrated through a numerical example, and it is shown that infills can be accounted for in the seismic design of frames during the normal course of design. Key words: masonry, infilled panels, frame behaviour, seismic design.

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Mohebkhah, Amin, and Marzieh Akefi. "Seismic Behavior of Concentrically Braced Steel Frames with Out-of-Plane Offset Irregularity." Open Civil Engineering Journal 11, no. 1 (June 30, 2017): 485–95. http://dx.doi.org/10.2174/1874149501711010485.

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Braced steel frames are sometimes designed with out-of-plane shifted bracing members on the first story due to architectural or functional considerations. Such frames are classified and designated as frames having the Type-4 horizontal structural irregularity entitled “frames with out-of-plane offset irregularity” as per theMinimum Design Loads for Building and Other Structures(ASCE 7-10). The purpose of this study is to investigate the nonlinear seismic behavior of ordinary steel concentrically braced frames with out-of-plane offset irregularity and evaluate their seismic design parameters. To this end, two 3-story and 6-story three-dimensional ordinary concentrically braced frames (OCBFs) with and without out-of-plane offset of one of the vertical elements on the first story were considered (i.e. irregular and regular configurations). The seismic design parameters considered in this study includes: frame overall overstrength factor, column overstrength factor and the inelastic dynamic inter-story drift demands. Nonlinear time-history dynamic analysis of the frames showed that overall overstrength factor of the low- and mid-rise irregular frames studied in this research is lower than that of the regular ones. Moreover, it was found that theSeismic Provisionsprescribed overstrength factor (i.e. Ωo=2.0) to amplify columns axial seismic forces in OCBFs is not conservative for the studied regular frames’ columns as well as the columns in the vicinity of the shifted bracing members on the first story of the irregular frames. Also, it was shown that the studied low- and mid-rise regular and irregular concentrically braced frames experience greater inter-story drift demands than predicted by the amplified elastic analysis proposed in the codes.

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Deam, Bruce L. "Seismic ratings for degrading structural systems." Bulletin of the New Zealand Society for Earthquake Engineering 34, no. 3 (September 30, 2001): 214–36. http://dx.doi.org/10.5459/bnzsee.34.3.214-236.

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A new method has been proposed for rating the seismic resistance of degrading bracing elements used in buildings constructed to NZS 3604. Most of these bracing elements are formed from thin cladding panels nailed or screwed to light timber frames, but the rating method is also used for bracing elements constructed from other materials. A new analytical model was developed as part of this study to accurately model the load-displacement responses of these bracing elements. A continuous pseudo-dynamic test method was developed to assess the accuracy of the analytical model in the BRANZ structural laboratory. The analytical model accurately predicted the time-displacement responses of three, pseudo-dynamically tested, 5.4 m long, light timber framed wall specimens, providing confidence in its use. The new rating method has shown that P21 rating procedure, used since 1979, was dangerously unconservative for the tested specimens. Factors that led to this discrepancy are briefly described. A simple modification to the current P21 rating procedure is proposed to re-rate specimens from existing test results, but this needs to be verified for a wider range of specimen responses than the three described herein.

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Bojórquez, Edén, Arturo López-Barraza, Alfredo Reyes-Salazar, Sonia E. Ruiz, Jorge Ruiz-García, Antonio Formisano, Francisco López-Almansa, Julián Carrillo, and Juan Bojórquez. "Improving the Structural Reliability of Steel Frames Using Posttensioned Connections." Advances in Civil Engineering 2019 (June 26, 2019): 1–10. http://dx.doi.org/10.1155/2019/8912390.

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In this paper, various moment-resisting steel frames (MRSFs) are subjected to 30 narrow-band motions scaled at different ground motion intensity levels in terms of spectral acceleration at first mode of vibration SaT1 in order to perform incremental dynamic analysis for peak and residual interstory drift demands. The results are used to compute the structural reliability of the steel frames by means of hazard curves for peak and residual drifts. It is observed that the structures exceed the threshold residual drift of 0.5%, which is perceptible to human occupants, and it could lead to human discomfort according to recent investigations. For this reason, posttensioned connections (PTCs) are incorporated into the steel frames in order to improve the structural reliability. The results suggest that the annual rate of exceedance of peak and residual interstory drift demands are reduced with the use of PTC. Thus, the structural reliability of the steel frames with PTC is superior to that of the MRSFs. In particular, the residual drift demands tend to be smaller when PTCs are incorporated in the steel structures.

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Reitman, Mark I. "Optimal Structural Design in the USSR." Applied Mechanics Reviews 42, no. 2 (February 1, 1989): 27–37. http://dx.doi.org/10.1115/1.3152419.

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Studies in structural optimization in Russia began more than a century ago and initially satisfied the needs of railroad engineering. Later Soviet academic researchers and engineers considered the optimum design of compressed and twisted bars, beams, arches, rigid frames, plates, shells, and various 3D structures under single and multiple statical, dynamical, and moving loads. Some new formulations of the optimization problems have been introduced and solved using classical and new mathematical methods. Several hundred contributions are briefly covered with references to 50 bibliographical sources.

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Komatsu, Kohei, and Akihisa Kitamori. "Static and Dynamic Properties of Portal Frames Composed of Built-Up Sawn Square Timber." Wood Research Journal 3, no. 1 (August 27, 2017): 36–43. http://dx.doi.org/10.51850/wrj.2012.3.1.36-43.

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In order to propose an alternative structural element to be used for wooden dwelling houses in rich forest area, we paid attentions to a portal frame structure which is composed of not glulam but built-up members whose raw materials are dried sawn timbers taken from plantation grown forest. For establishing design procedure of the structural element, we made two different types of portal frames and conducted, at first, basic dynamic test to estimate natural frequency and dumping factors by fixing small shake excitation machine on the portal frames, then static push-pull cyclic loading tests were conducted until failure. The natural frequency of both portal frames was almost same but the higher order frequencies were likely to be affected by the difference of shear reinforcement of built-up members by hardwood dowels. While on static properties, as both portal frames failed in brittle manner due to bending failure at column or tear off at connection plate made of compression wood, further improvement of connection system was required for obtaining more stable alternative elements to glulam.

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Mo, Y. L., and W. L. Hwang. "Dynamic response of prestressed concrete frames." Engineering Structures 16, no. 8 (November 1994): 577–84. http://dx.doi.org/10.1016/0141-0296(94)90043-4.

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Jabbari, Hamed, Reza Vahdani, Mohsen Gerami, and Hossein Naderpour. "Seismic Performance of Steel Moment Frames Containing Concentric Bracing Equipped with Shape Memory Alloys." Open Civil Engineering Journal 13, no. 1 (December 20, 2019): 189–200. http://dx.doi.org/10.2174/1874149501913010189.

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Background: A building’s stability is a critical design element that structural engineers must understand. And, utilization of Shape Memory Alloys (SMAs) in steel structures can importantly diminish seismic residual deformations, which will facilitate postseismic retrofitting. Objective: The aim of the present study was to evaluate the seismic behavior of 7-story and 15-story steel frames with moment frame system having chevron concentric brace equipped with Shape Memory Alloys (SMAs). Braces containing various amount of alloy (including 20%, 40%, 60%, 80% and 100%) applied to study SMAs effect on structural performance. Relatively persistent displacement of the structure as well as its relative maximum displacement under the earthquake imposing on frame models were investigated using non-linear dynamic analysis by OpenSees finite element software. The earthquakes were in near- fault nine accelerographs, which involved various maximum accelerations. Results: Results indicated a reduction in relatively persistent displacement using 20% SMAs in braces. Addition more amount of alloy resulted in less relative displacement as compared to steel one braces. Conclusion: Applying SMAs brace showed a reduction in persistent structural displacement in any types of frames. Furthermore, adding more than 20% SMAs to the brace, resulted in a decrease in structural displacement.

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Leung, A. Y. T. "Nonconservative dynamic axial–torsional buckling of structural frames using power series." International Journal of Mechanical Sciences 51, no. 11-12 (November 2009): 807–15. http://dx.doi.org/10.1016/j.ijmecsci.2009.09.011.

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Suzuki, Yoshiyuki, and Masaki Maeno. "Structural mechanism of traditional wooden frames by dynamic and static tests." Structural Control and Health Monitoring 13, no. 1 (January 2006): 508–22. http://dx.doi.org/10.1002/stc.153.

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Martinez, Bridget, Andre Green, Moises Felipe Silva, Yongchao Yang, and David Mascareñas. "Sparse and Random Sampling Techniques for High-Resolution, Full-Field, BSS-Based Structural Dynamics Identification from Video." Sensors 20, no. 12 (June 22, 2020): 3526. http://dx.doi.org/10.3390/s20123526.

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Video-based techniques for identification of structural dynamics have the advantage that they are very inexpensive to deploy compared to conventional accelerometer or strain gauge techniques. When structural dynamics from video is accomplished using full-field, high-resolution analysis techniques utilizing algorithms on the pixel time series such as principal components analysis and solutions to blind source separation the added benefit of high-resolution, full-field modal identification is achieved. An important property of video of vibrating structures is that it is particularly sparse. Typically video of vibrating structures has a dimensionality consisting of many thousands or even millions of pixels and hundreds to thousands of frames. However the motion of the vibrating structure can be described using only a few mode shapes and their associated time series. As a result, emerging techniques for sparse and random sampling such as compressive sensing should be applicable to performing modal identification on video. This work presents how full-field, high-resolution, structural dynamics identification frameworks can be coupled with compressive sampling. The techniques described in this work are demonstrated to be able to recover mode shapes from experimental video of vibrating structures when 70% to 90% of the frames from a video captured in the conventional manner are removed.

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Yang, Yuedong, Jiqing Chen, Fengchong Lan, Fei Xiong, and Zicong Zeng. "Joints Parameters Identification in Numerical Modeling of Structural Dynamics." Shock and Vibration 2018 (June 5, 2018): 1–11. http://dx.doi.org/10.1155/2018/2365759.

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The dynamics of assembled structures are significantly dependent on joints. Joints parameters, owing to be difficultly measured, are always ignored by pure rigid in numerical modeling and it will result in unreliable or even error descriptions. 1~3 Hz deviations may cause resonance especially in engineering optimization issues; hence it is necessary to identify joints parameters for structural dynamics investigation. In present work, multiobjective optimization algorithms are used to identify joints parameters by approaching actual test results in each series of structure to decrease unreliable or error for numerical modeling. Taking automotive dynamics with seam-welding and spot-welding as examples, the relationship of joints parameters perturbation and structural dynamics is derived to give the selecting reason of parameters’ identification. The actual dynamics of an SUV’s frame and a thin-walled part in BIW (body in white) are utilized to validate the methodology. Results demonstrate that the validated model has enough accuracy to reflect the dynamics of the actual structure. The methodology provides reliable guarantee for dynamic analysis and the design of structure.

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Diaz, Orlando, Enrique Mendoza, and Luis Esteva. "Seismic Ductility Demands Predicted by Alternate Models of Building Frames." Earthquake Spectra 10, no. 3 (August 1994): 465–87. http://dx.doi.org/10.1193/1.1585785.

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Peak values of story ductility demands produced by earthquakes on several models of multistory rigid frames are evaluated by means of step-by-step nonlinear dynamic analysis of structural response to simulated ground motion time histories. The models studied include the basic rigid frame model with nonlinear behavior concentrated at plastic hinges eventually forming at the ends of beams and columns, as well as two approximations, the conventional shear-beam system and a shear-frame system constituted by ordinary reinforced concrete columns and infinitely stiff and strong beams. Two families of models were studied, including seven-story and fourteen-story systems, respectively. The contributions of soil-structure interaction, stiffness-degradation and P-delta effects were analyzed. The equivalent shear-beam model produced results clearly different from those of its rigid frame counterpart: while peak values of story ductility demands vary gradually along the height of rigid frames, they concentrate at the bottom story of shear-beam systems, where they are significantly greater than for the corresponding rigid frame. The responses of both, shear-beam and shear-frame systems, displayed a more pronounced sensitivity to variations in the lateral strengths of structural members than that observed in rigid frames.

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Hong, Sung Gul, Namhee K. Hong, and Sun Young Lee. "Hysteretic Behavior of Korean Traditional Wooden Frames." Advanced Materials Research 133-134 (October 2010): 703–8. http://dx.doi.org/10.4028/www.scientific.net/amr.133-134.703.

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The objective of this paper is to provide basic information on structural behavior of Korea traditional wooden frames under earthquake loading. One of prototype wooden frames for this study was chosen from a designated national treasure in Korea. A series of experimental work were prepared to investigate the behavior and hysteresis characteristics of traditional wooden frames under cyclic lateral loading. Three test specimens of a full scale were performed for cyclic hysteretic behaviors based on one static test specimen as a pilot test. The experimental observation showed stiffness degradations and slips after experiencing initial yield point and the first cycle at a new larger displacement due to inherent gaps in connections between columns and connection parts of beams and a gradual indentation of interfaces under pull and push. Addition of structural components such as an upper beam and clay-filled wall to the basic beam and columns increased the initial stiffness, strength and energy dissipation than those of basic frames. The behaviors of the wooden frames were simulated by DRAIN-2DX program for the dynamic analysis of an entire wooden frame system. Comparison between analysis models and the experimental behaviors showed that the behavior of wooden frames under consideration could be represented by a combination of link and truss elements. The maximum response of a wooden frame system under three earthquakes showed a safe behavior for a potential earthquake.

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Basim, Shahnaz, Farzad Hejazi, and Raizal Saifulnaz Bin Muhammad Rashid. "Embedded carbon fiber-reinforced polymer rod in reinforced concrete frame and ultra-high-performance concrete frame joints." International Journal of Advanced Structural Engineering 11, S1 (November 28, 2019): 35–51. http://dx.doi.org/10.1007/s40091-019-00253-7.

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AbstractBeam–column joints play an important role in providing lateral stiffness and integrity of frames during dynamic loading such as earthquake. In the high humidity areas, during functioning of the building cracks occur, which leads to the corrosion of the reinforcement due to the environmental exposures. Therefore, one of the main failures mechanism of building during an earthquake is caused by easily yielding of corroded steel reinforcement, which leads to reduce functionality of the frame joints in transferring the loads. This study proposed a new design to reinforce the beam-column joints with embedded carbon fiber-reinforced polymer (CFRP) rods, due to their extremely high strength and stiffness, along with the fact that they will not rust or corrode and very light weight. CFRP rods are used in reinforced concrete (RC) frame and ultra-high-performance concrete (UHPC) frame subjected to dynamic load. The prototype of the proposed design is constructed as frame with conventional concrete and frame with UHPC material to conduct experiments Test as well as numerical analysis to evaluate the performance of the proposed joints under dynamic loads. The results showed improvement in the performance of the frames reinforced with embedded CFRP in joints in terms of lateral load resistance capacity, ductility behaviour, overall stiffness, and failure mechanism.

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Fedorova, Nataliya. "Determination of dynamic durabilities and dynamic strength of armature in the elements of the constructive system at its flash structural restructuring." MATEC Web of Conferences 251 (2018): 02009. http://dx.doi.org/10.1051/matecconf/201825102009.

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The results of modeling and computational analysis of the static-dynamic deformation of the reinforced concrete frame-and-rod system are presented for special emergency actions caused by the sudden removal of one of the supporting elements. On the basis of energy, without the apparatus of the dynamics of structures, analytical dependences are constructed to determine the increments of the dynamic extensions in the stretched armature and the dynamic strength of the reinforcement in the sections of the frame elements under the indicated effects on the first half-wave of the structure's oscillations. Verification of the proposed analytical dependencies is performed by comparing the theoretical values of the calculated parameters with the experimental data. It is shown that the constructed analytical dependencies allow to determine quite strictly the investigated dynamic parameters of deformation of the loaded reinforced concrete framed structural systems of buildings and structures under their dynamic overloading by special emergency action associated with sudden structural reorganization of the structural system.

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Carr, A. J., and P. J. Moss. "Impact between buildings during earthquakes." Bulletin of the New Zealand Society for Earthquake Engineering 27, no. 2 (June 30, 1994): 107–13. http://dx.doi.org/10.5459/bnzsee.27.2.107-113.

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A numerical study of the parameters affecting the impact between adjacent buildings subjected to seismic excitation has been carried out in an endeavour to quantify the relative importance of the structural parameters. A two-dimensional inelastic dynamic analysis program was used to model various combinations of adjacent framed structures subjected to ground accelerograms and where the frames are assumed to be separated by distances sufficiently small as to permit contact. Collisions were modelled using special contact elements which will transmit forces when the specified gap has been closed. It will be shown that where there are adjoining frames are of different heights, large increases in response are observed in the upper part of the taller frame. Pounding can also amplify the effects of localised changes in stiffness and strength up the frame-, producing member demands greatly in excess of the normal design values.

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Wu, Jun Hui, Quan Zhou, Jie Chen, Hui Ping Si, and Chi Bin Zhang. "Structural Design for Dynamic Roller Device in Transporting Unit of Biomass Pyrolytic System." Applied Mechanics and Materials 157-158 (February 2012): 361–66. http://dx.doi.org/10.4028/www.scientific.net/amm.157-158.361.

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With the full study of industrial process control technology for thermal, chemical industry, the application process, the FCS system of biomass pyrolysis unit was development combined with the actual. Feeding system uses the weighing system of dynamic belt with an advanced embedded technology. The computing speed and accuracy, data processing compared with traditional electronic belt scale, information exchange, integration, reliability and stability will be greatly improved. The technology shall be constantly upgraded and vigorously promoted. The frame structures of dynamic roller were various in forms. Different systems can be used to the frame with different scale structures. The suspension of multi-scale frame of the roller was used widely currently. The modeling and structural optimization of the frames in reasonable scale were designed with reducing the use of metal materials, optimizing the overall performance of mechanical systems and improving the weighing accuracy. The analysis of dynamic roller in scale weighing and speed principle, the establishment of a multi-roller single floating frame structure of the scale model and the analysis of the roller of the force were built. The verification in final design through the ANSYS software is reasonable.

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Valente, Marco. "Seismic Performance of Existing R/C Frames Strengthened by Steel Plate Shear Walls." Applied Mechanics and Materials 193-194 (August 2012): 1470–75. http://dx.doi.org/10.4028/www.scientific.net/amm.193-194.1470.

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This study investigates an innovative method based on low yield steel plate shear walls for seismic retrofitting of existing reinforced concrete (R/C) structures. A simplified numerical model of steel shear panels is developed for global analyses of multi-story R/C frames. The seismic performance of a non-ductile five-story R/C frame retrofitted with steel plate shear walls is evaluated in terms of drift control and energy dissipation capacity using nonlinear dynamic analyses. The results obtained by the application of two different story-wise distributions of steel plates are compared. In case of retrofitted frames a considerable decrease of the maximum top displacements is registered and the energy dissipated by the primary structural elements is significantly reduced for severe seismic actions. The energy dissipation concentrates in the steel panels, reducing the plastic demand on the structural members, along with the potential for structural damage. The different story-wise distributions of the steel panels change the damage distribution throughout the frame. The uniform arrangement of the steel panel thickness along the height of the frame causes a concentration of damage in the columns of the first story. In case of steel panel distribution proportional to story shear, the energy dissipation results more uniform over the height of the frame and a significant decrease of damage is registered for the columns of all the storeys.

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Bahrami, Alireza, and Mahmood Heidari. "Evaluation of structural response of composite steel-concrete eccentrically buckling-restrained braced frames." Journal of Applied Engineering Science 18, no. 4 (2020): 591–600. http://dx.doi.org/10.5937/jaes0-25497.

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The main purpose of this paper is to evaluate the structural response of composite steel-concrete eccentrically buckling-restrained braced frames (BRBFs). The finite element (FE) software ABAQUS is employed to nonlinearly analyse the BRBFs. Comparing the modelling and experimental test results validates the FE modelling method of the BRBF. Three different strong earthquake records of Tabas, Northridge, and Chi-Chi are selected for the nonlinear dynamic analyses. A BRBF is then designed having a shear link. Afterwards, the designed BRBF is analysed under the selected earthquake records using the validated modelling method. The lateral displacements, base shears, and energy dissipations of the frame and shear link rotations are achieved from the analyses of the BRBF. The results are compared and discussed. The obtained BRBF results are also compared with their corresponding steel eccentrically braced frame (EBF) results. It is concluded that the BRBF can generally accomplish the improved structural response compared with the EBF under the earthquake records. Meanwhile, the BRBF has larger base shear capacity than the EBF. Moreover, the BRBF dissipates more energy than the EBF.

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Chau, Vu Minh, and Hien Bich Vo. "Structural Dynamics Analysis of 3-U CubeSat." Applied Mechanics and Materials 894 (September 2019): 164–70. http://dx.doi.org/10.4028/www.scientific.net/amm.894.164.

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The development of CubeSats has been advanced significantly during the past two decades for both scientific research and industrial purposes. During the manufacturing process, every CubeSat must satisfy various system requirements in which the structural analysis is one of the most vital necessity in order to assure a normal operation of the CubeSat during its working time in space. In the conceptual design phase, structural dynamics is a mandatory step to determine the natural frequencies of individual bodies, the deformation and stress induced at the corresponding vibration modes to prevent structural failure. In this work, IGOSat, a 3-Unit CubeSat, which was developed at the Paris Diderot University is exanimated in term of modal, harmonic response, and random vibration analysis at the time of ground testing as well as the launching phase using ANSYS software. These numerical simulations conducted according to the CubeSat Design Specification and the system requirements of QB50 project. The minimum natural frequency of the CubSat obtained to be 363.17 (Hz), which passed the required frequency of 90 (Hz). Moreover, the Harmonic and Random vibration analyses indicate that the peak response of normal stress, as well as deformation values obtained, are far lesser compared to the yield strength of the frame structure and subsystem materials. Hence, our numerical analysis found that the CubeSat remains intact during the launch environment.

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G.K., Arunvivek, and Saravanakumar R. "Vibration Control Of Steel Frames Using Magnetorheological Dampers: A New Control Algorithm." International Journal of Civil, Environmental and Agricultural Engineering 1, no. 1 (May 30, 2019): 62–66. http://dx.doi.org/10.34256/ijceae1919.

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Control technologies application to steel structure is mainly anticipated to enhance the structural performance against natural hazards. In particular smart base isolation system connected with semi-active isolator at the base with controllable semi devices gaining impulse for its efficiency and economic reasons. Generally the development of control design strategies through system dynamics concept had not been considered entirely for structural applications. Structural characteristics which help to divulge structural properties, hitherto flout by civil engineering circle are assimilated with control techniques to construct indices in modal and nodal coordinates for the endurance of the control action to utilize their fullest capabilities. In this study, an isolated 3D steel frame model is developed. Magneto-Rheological dampers are fixed with 3D steel frame model which act as a smart control device. Besides, Force transducers and Piezoresistive Actuator in tandem with Deltatron conditioning amplifier are also used. Presently many techniques are employed for the optimum placement of actuators and sensors in vibration control systems. The concept of controllability-observability is used in these methods. The specific relationship between the vibration modes and controllability-observability simplifies this approach. This study envisaged the compatibility of force transducers along with triaxial and uniaxial accelerometers fixed at various trial spots on the model structure to quantify the damping force and absolute accelerations of the structure and the dampers individually, positioned in the system, against the excitation of the structure.

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Yussof, Mustafasanie M., Jordan Halomoan Silalahi, Mohd Khairul Kamarudin, Pei-Shan Chen, and Gerard A. R. Parke. "Numerical Evaluation of Dynamic Responses of Steel Frame Structures with Different Types of Haunch Connection Under Blast Load." Applied Sciences 10, no. 5 (March 6, 2020): 1815. http://dx.doi.org/10.3390/app10051815.

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This research is aimed at investigating the dynamic behaviour of, and to analyse the dynamic response and dynamic performance of steel frames strengthened with welded haunches subjected to a typical hydrocarbon blast loading. The structural dynamic analysis was carried out incorporating the selected blast load, the validated 3D model of the structures with different welded haunch configurations, steel dynamic material properties, and non-linear dynamic analysis of multiple degree of freedom (MDOF) structural systems. The dynamic responses and effectiveness of the reinforced connections were examined using ABAQUS finite element software. Results showed that the presence of the welded haunch reinforcement decreased the maximum frame ductility ratio. Based on the evaluation of the results, the haunch reinforcements strengthened the selected steel frame and improved the dynamic performance compared to the frame with unreinforced connections under blast loading, and the biggest haunch configuration is the “best” type.

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Filiatrault, André, and Bryan Folz. "Nonlinear earthquake response of structurally interconnected buildings." Canadian Journal of Civil Engineering 19, no. 4 (August 1, 1992): 560–72. http://dx.doi.org/10.1139/l92-067.

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This paper evaluates the performance of closely spaced plane steel framed buildings interconnected by horizontal structural links to prevent pounding during earthquake excitations. Friction damping capability is incorporated into the modelling of these structural links in order to also determine their potential for dissipating energy during a seismic event. Six pairs of building models, having widely different dynamic characteristics, are considered in this investigation. A parametric study, utilizing nonlinear time-history dynamic analysis, is performed to determine the optimum properties for the structural links when each building pair is excited by three different historical earthquake ground motions. This is followed by a detailed reponse analysis comparison of each of these optimized friction damped coupled structures against their uncoupled and elastically coupled counterparts. Key words: earthquake, steel, frames, inelastic, pounding, friction, damping.

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Ahmad, M. E., N. Ahmad, S. Pervez, A. Iqbal, A. Z. Khan, M. E. Rahim, W. Hassan, K. Umer, and K. Khan. "Seismic Performance Evaluation of Modern Bare and Masonry-Infilled RC SMRF Structures." Advances in Civil Engineering 2019 (October 30, 2019): 1–15. http://dx.doi.org/10.1155/2019/6572465.

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Improper execution of modern code-designed structures in many developing countries have resulted in significant deficient building stock; low strength of concrete, reduced reinforcement, inappropriate detailing of beam-column members, and lack of lateral ties in joint panels. Observations based on earthquake-induced damages and experimental studies conducted on such buildings have revealed significant vulnerability of beam-column joints of bare moment-resisting frame structures. Shake table tests were conducted on selected three 1 : 4 reduced-scale three-story reinforced concrete (RC) moment-resisting frames, including one bare RC frame and two masonry-infilled RC frames, having relatively lower bay width-to-height ratio. The models were tested under multilevels of seismic excitations using natural acceleration time history of 1994 Northridge and also free vibration tests, to acquire the models’ dynamic characteristics, i.e., frequencies and elastic viscous damping, and seismic response parameters, i.e., roof displacement, interstory drift and interstory shear, and seismic response curves, in order to understand the role of masonry infill in the selected frames under moderate seismic actions. The inclusion of masonry infill avoided joint shear hinging of the frame. Additionally, the infill provided energy dissipation to the structure through masonry sliding over multiple cracks. This enabled the structure to control seismic displacement demand and resist relatively higher ground motions, yet limiting structural damages.

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Rizwan, M., N. Ahmad, J. Akbar, B. Ilyas, Arifullah, A. Ali, M. E. Ahmad, S. Pervez, M. E. Rahim, and M. A. Z. Khan. "Global Seismic Fragility Functions for Low-Rise RC Frames with Construction Deficiencies." Advances in Civil Engineering 2020 (July 6, 2020): 1–18. http://dx.doi.org/10.1155/2020/3174738.

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Shake table tests were performed on three two-story 1 : 3 reduced scale RC frame structures, representative of buildings with construction deficiencies in Pakistan. The models were subjected to the natural accelerogram of the 1994 Northridge earthquake and tested under multiple scaled excitations until the models attained incipient collapse state. The models’ damage mechanisms were studied, and the seismic response in terms of floor acceleration and floor displacement was retrieved. A uniform damage scale was developed for global performance assessment of considered deficient RC frames, listing average estimate of limit states’ drifts and base shear coefficients, with measured uncertainty, and describing frame damage condition. Numerical frame models were prepared in finite element-based program SeismoStruct and calibrated against experimental tests. The frames were analyzed through incremental dynamic analyses. Seismic fragility functions were derived using a probabilistic-based methodology, which may be used for global damageability assessment of the considered frame building typology. Available building damage-to-loss factors were employed to transform structural damages to repair cost ratio, which were correlated with seismic intensity (repair cost ratio versus seismic intensity) to derive the seismic vulnerability curve, which may be used for the direct economic loss estimation of the considered frame building typology.

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42

Konstandakopoulou, Foteini, George Hatzigeorgiou, Konstantinos Evangelinos, Thomas Tsalis, and Ioannis Nikolaou. "A New Method to Evaluate the Post-Earthquake Performance and Safety of Reinforced Concrete Structural Frame Systems." Infrastructures 5, no. 2 (February 1, 2020): 16. http://dx.doi.org/10.3390/infrastructures5020016.

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This study examines the relation between maximum seismic displacements and residual displacements for reinforced concrete building structures. In order to achieve a reliable relationship between these critical structural parameters for the seismic performance of concrete buildings, an extensive parametric study is conducted by examining the nonlinear behavior of numerous planar framed structures. In this work, dynamic inelastic analyses are executed to investigate the seismic behavior of two sets of frames. The first group consists of four planar frames which have been designed for seismic and vertical loads according to modern structural codes while the second group also consists of four frames, which have been designed for vertical loads only, in order to examine older structures that have been designed using codes with inadequate seismic provisions. These two sets of buildings are subjected to various earthquakes with different amplitudes in order to develop a large structural response databank. On the basis of this wide-ranging parametric investigation, after an appropriate statistical analysis, simple empirical expressions are proposed for a straightforward and efficient evaluation of maximum seismic displacements of reinforced concrete buildings structures from their permanent deformation. Permanent displacements can be measured in-situ after strong ground motions as a post-earthquake assessment. It can be concluded that the measure of permanent deformation can be efficiently used to estimate the post-seismic performance level of reinforced concrete buildings.

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Baloević, G., J. Radnić, and A. Harapin. "Numerical dynamic tests of masonry-infilled RC frames." Engineering Structures 50 (May 2013): 43–55. http://dx.doi.org/10.1016/j.engstruct.2012.11.034.

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PAPADRAKAKIS, MANOLIS, NIKOS D. LAGAROS, and VAGELIS PLEVRIS. "OPTIMUM DESIGN OF SPACE FRAMES UNDER SEISMIC LOADING." International Journal of Structural Stability and Dynamics 01, no. 01 (March 2001): 105–23. http://dx.doi.org/10.1142/s0219455401000093.

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The objective of this paper is to perform structural optimization under seismic loading. Combinatorial optimization methods and in particular algorithms based on Evolution Strategies are implemented for the solution of large-scale structural optimization problems under seismic loading. In this work the efficiency of a rigorous approach in treating dynamic loading is investigated and compared with a simplified dynamic analysis in the framework of finding the optimum design of structures with minimum weight. In this context a number of accelerograms are produced from the elastic design response spectrum of the region. These accelerograms constitute the multiple loading conditions under which the structures are optimally designed. This approach is compared with an approximate design approach based on simplifications adopted by the seismic codes. The results obtained for a characteristic test problem indicate a substantial improvement in the final design when the proposed optimization procedure is implemented.

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45

Šnirc, Ľuboš, and Jan Ravinger. "Stability and Vibration of Imperfect Column and Slender Web." Advanced Materials Research 969 (June 2014): 328–31. http://dx.doi.org/10.4028/www.scientific.net/amr.969.328.

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Using the geometric non-linear theory (The Total Lagrange Description) in dynamics we can establish the problem of the natural vibration of the structure including the effects of the structural and geometrical imperfections. The incremental stiffness matrix can take into account the residual stresses (structural imperfections) and the geometrical initial displacements (geometrical imperfections) as well. The behaviour of columns, frames and thin-walled structures is sensitive to imperfections. This theory and results can be used as a base for the non-destructive method for the evaluation of the level of the load and the imperfections.

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Wählisch, Martin. "Deconstructing Peace and Security Dynamics in the Gulf Region." Sicherheit & Frieden 37, no. 3 (2019): 129–34. http://dx.doi.org/10.5771/0175-274x-2019-3-129.

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This article focuses on current peace and security dynamics in the Gulf region. It applies system theory aspects to better understand the underlying patterns of evolving political alliances and fault lines. The article points out that power imbalances, frames of a common enemy and interconnected proxy conflicts keep frictions going. The author argues that dialogue efforts in this context need to address those structural impediments to peace in the region. The article concludes with general observations and conditions for a potential security architecture of the region.

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Waegter, J., K. B. Olsen, and K. A. Sorensen. "Structural Engineering Aspects of the STAR Platform." Journal of Offshore Mechanics and Arctic Engineering 114, no. 4 (November 1, 1992): 272–77. http://dx.doi.org/10.1115/1.2919980.

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Based on the economic frames of the late eighties, the general urge to develop cheap and small platforms for marginal fields is outlined. Through a case story covering main aspects of the structural development and design of the STAR platforms, originated by Mærsk Olie og Gas AS, it is demonstrated how a new, cheap jackup installed platform type has been developed for shallow Danish North Sea conditions. Due to the platform’s relatively slender layout, it is more susceptible to dynamic loads than traditional jackets. Therefore, special investigations have been carried out for ship impact, fatigue, vortex shedding and pile driving-induced vibrations. Both the approach chosen for the analyses and design, as well as typical results, have been included. Finally, the present record of this new platform has been given.

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York, Timothy, Radoslav Marinov, and Viktor Gruev. "260 frames-per-second 648x488 resolution division-of-focal-plane polarimeter with structural dynamics and tracking applications." Optics Express 24, no. 8 (April 8, 2016): 8243. http://dx.doi.org/10.1364/oe.24.008243.

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Javanpour, M., and P. Zarfam. "Application of Incremental Dynamic Analysis (IDA) Method for Studying the Dynamic Behavior of Structures During Earthquakes." Engineering, Technology & Applied Science Research 7, no. 1 (February 12, 2017): 1338–44. http://dx.doi.org/10.48084/etasr.902.

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Prediction of existing buildings’ vulnerability by future earthquakes is one of the most essential topics in structural engineering. Modeling steel structures is a giant step in determining the damage caused by the earthquake, as such structures are increasingly being used in constructions. Hence, two same-order steel structures with two types of structural systems were selected (coaxial moment frames and moment frame). In most cases, a specific structure needs to satisfy several functional levels. For this purpose, a method is required to determine the input request to the structures under possible earthquakes. Therefore, the Incremental Dynamic Analysis (IDA) was preferred to the Push-Over non-linear static method for the analysis and design of the considered steel structures, due its accuracy and effect of higher modes at the same time intervals. OpenSees software was used to perform accurate nonlinear analysis of the steel structure. Two parameters (spectral acceleration and maximum ground acceleration) were introduced to the modeled frames to compare the numerical correlations of seismic vulnerability obtained by two statistical methods based on the "log-normal distribution" and "logistics distribution", and finally, the parameters of displacement and drift were assessed after analysis.

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Escobar, J. Alberto, J. Jesús Sosa, and Roberto Gómez. "Damage detection in framed buildings." Canadian Journal of Civil Engineering 28, no. 1 (February 1, 2001): 35–47. http://dx.doi.org/10.1139/l00-071.

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The transformation matrix method for damage detection in structural elements of frame buildings, expressed as the loss of stiffness, is proposed and evaluated. The method, which allows the locating and assessing of the damage magnitude of structural elements by considering the contribution of each of them to the overall performance of the structure, is applicable to two- and three-dimensional building frames of several storeys and bays with one or several damaged elements. Effects of uncertainties in the experimental measurements of the dynamic characteristics and in the precision of the numerical representation of the structure on the method proposed are evaluated. A three-dimensional frame model with different simulated damage states and a reinforced concrete plane frame model damaged using an earthquake record as excitation are studied. Results show the good agreement between the estimated damage computed with the proposed method and the true value of damage.Key words: damage detection, transformation matrix, structural damage, damage assessment.

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Journal articles on the topic 'Structural frames. Structural dynamics'

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