Papers by Keyword: Dynamic Analysis

Abstract: The head-form test on actual automotive windscreen with the analytic method of explicit dynamics is researched in this paper. Based on the experiment specification, the geometric models of head-form weight and laminated glass for actual automotive windscreen are built, and the loading conditions of the head-form test are also acquired. According to the analysis results, the process of crack initiation & propagation and the failure mechanism in laminated glass are studied, which is of great significance for the evaluation on laminated glass for actual automotive windscreen.

Abstract: This paper presents the validation process of the GenEcAm program made by the author by comparing the results obtained with this program with the results obtained with the SAP2000 program at the dynamic analysis of a P+10E building equipped with viscous fluid dampers, one on each facade on each level. The results obtained with these two programs are very close, which validates the correctness of the analytical and computational model that underpinned the creation of the GenEcAm program. The GenEcAm program allows the use of 9 theoretical models of hysteresis to simulate seismic behavior of the dampers that equippe the structure of a building.

Abstract: This paper presents the difference between the results obtained with GenEcAm in simulating the seismic behavior of a P + 10E building equipped with SERB dampers modeled with two hysteresis models, namely the classic Bouc-Wen model and a Bouc-Wen modified model Bouc-Wen_Exp, in order to highlight the most appropriate theoretical model for modeling these dampers. The GenEcAm program is created by the author for the dynamic analysis during seism for structures of buildings equipped with different earthquake damping systems, with the possibility to use 9 different theoretical models of hysteresis for simulating the hysterical behavior of seismic energy dissipation devices that fit the antiseismic system of the analysed building.

Abstract: Hybrid simulation is an economical structural testing technique in which the critical part of the structure expected to respond in the inelastic range is tested physically whereas the rest of the structure is modelled numerically using a finite element analysis program. The article describes the development of a computational model for the hybrid simulation of the seismic collapse of a steel two-tiered braced frame structure due to column buckling. The column stability response in multi-tiered braced frames is first presented using a pure numerical model of the braced frame studied. The development of the hybrid simulation computational model is then discussed. Effects of initial out-of-straightness imperfections and axial stiffness, P-Delta analysis approach, and gravity analysis technique on the hybrid simulation results are evaluated using a numerical hybrid simulation model. Finally, the results of a continuous pseudo-dynamic hybrid simulation of the seismic response of the steel multi-tiered concentrically braced frame are presented. The test showed that failure of columns by instability is a possibility and can lead to collapse of multi-tiered braced frames, as was predicted by numerical analysis. Furthermore, suitable modeling methods are proposed for hybrid simulation of steel braced frame structures.

Abstract: The submitted paper is focused on the design of Tuned Mass Damper in order to reduce excessive level of vibration. This device is designed to be active at the first natural frequency of the structure. Subsequently, the efficiency of the new dynamic system (structure-TMD) is verified for several types of time-dependent loads, which express swaying vandal, jumping vandal and moving pedestrian.

Abstract: This paper deals with static and dynamic analysis of asymmetric high-rise building. Two alternatives have been analysed – without dilatation and with dilatation. Then, the influence of the dilatation was discussed. The building was located in 4^th seismic area in Slovakia (Bratislava). The description of the building, applied load, considered soil-structure interaction, created calculating models, used analysis and obtained results are mentioned here. The conclusions and the photos of defective repairs of real structures are depicted at the end of the paper.

Abstract: The analysis of the sliding contact behavior for friction lining is an important issue in design of centrifugal clutches. In this study, a numerical model based on the moment equilibrium and contact mechanics has been developed to analyze the dynamics of a commercial centrifugal clutch. The proposed dynamic model can estimate the rotational speed of initial contact, output torque, and contact pressure for friction lining during the clutch operation. The comparison of the numerical and experimental results for the output torque of the analyzed centrifugal clutch shows the simulation agrees well with the experimental data. The difference for the maximum output torque is around 1.9%, which shows the effectiveness of the proposed method. The proposed dynamic model can reduce unnecessary physical prototypes and experimental cost, and is expected to be used to improve the design of the centrifugal clutches.

Abstract: For the study of first conveyor chain dynamics behavior when it is started and seek the theory basis for the chain breakage on first conveyor, set up the mathematical model of the first conveyor and its scraper chain by using finite-element method. And then did the dynamics characteristic analysis between scraper chains with material, set up the differential equation. Took advantage of the mathematical model and the differential equation, and combined with the type of EBZ160 road header's technical parameters, did dynamic simulation. It draw a conclusion that during the start-up process the chain speed fluctuates a large range between, the maximum stress value on scraper chain is 1.15×10⁴N appeared after 1s, chain tension adjustment time is about 10s, the biggest adjustment time is 12s.

Abstract: This paper analyzes the dynamic response of a shear deformable functionally graded porous beam under a point harmonic load. Timoshenko beam theory is employed to include the effect of transverse shear strain. The elasticity moduli and mass density of the porous beam vary continuously in the thickness direction based on two different porosity distributions. The relationship between porosity and density coefficients are determined according to the mechanical property of an open-cell metal foam. The equations of motion are derived and solved by applying Ritz method in the space domain and Newmark-β method in the time domain. The dynamic deflections are obtained for porous beams with different boundary conditions. A detailed numerical analysis is presented to show the effects of porosity coefficient and slenderness ratio on the dynamic response of porous beams. The influence of porosity distribution pattern is highlighted to shed a useful insight into the design of functionally graded porous structures.

Abstract: In this contribution, we employ non-stationary filtered Gaussian processes as an enrichment of a periodic mean value in order to approximate crowd loads on grandstands. Our work generalizes previous considerations where the superposition of a mean value and a stationary filtered Gaussian noise was used, and helps therefore to better predict the response of a structure mainly in the transition stages. We specify general theory of stochastic differential equations within the context of grandstands by recalling particular moment equations, and demonstrate its benefits or drawbacks on two simple examples. Overall performance is measured in terms of the second moment evolutions in time and in terms of the total up-crossings of the system's response compared to previously developed stationary approximation and Monte Carlo simulation. Throughout, only an active part of a crowd is considered.