Applied Mechanics and Materials Vols. 353-356

Abstract: The seismic dynamic responses on two buildings with the vibration isolation system have been evaluated and the results show that the dry friction plate-reset spring isolation system is apparently effective if the reasonable parameters could be obtained by optimization. The maximum inter-storey drift could be drastically decreased by about 80% at base storey or about 60% at top storey. The elastic coefficient of the reset spring should be larger than the lower limit in order for the effective reposition ability of the system. On the other hand, the influence of the vertical seismic action to the horizontal dynamic response is so small that it could be neglected.

Abstract: In this paper, a new type shape memory alloy (SMA)-viscous damper is studied by experiment and FEM analysis. As the main mechanical parameters of the damper were obtained by experiment, the damping effect of this composite damper for an eight-story steel frame structure model was discussed by using ANSYS. Both the damped and undamped structures had been analyzed and the vibration responses of this steel framework were compared. The results show that the damper has both the energy dissipating and reset features with the hysteretic loop under cyclic loading-unloading, and the new composite damper has significant damping effect for steel frame structure.

Abstract: Based on container cranes seismic load calculation criteria with structural dynamics and damage modes of container crane under earthquake, the seismic isolation device of this over-span flexible structure and its associated parameters selection were investigated. Taking the first crane equipped with isolating device as an example, through dynamic analysis and simulating to crane flexible system with isolation device under the earthquake, efforts was made to research for suitable isolation device and design method for port crane. The calculation and analysis in the present study could provide a new way for the container cranes isolation device design and assessment of the structural anti-seismic effect

Abstract: A two-story masonry housing model was made in this paper. According to Intensity 7, adjusted Northridge record was selected to be the ground motion input in the pseudo-dynamic test. Pseudo-dynamic test and pseudo-static test were carried out to investigate the seismic behavior of the model structure. The time-history curves of the acceleration, velocity, displacement and restoring force of the structural response were obtained besides the time-history curves of the measuring points of the structure. Also the steel strain of the tie-columns and the hysteresis loops of the structure were obtained. The result shows multi-story confined masonry structures possess superior seismic performance if coordinated with the provision specified in the current compulsory design code and it can continue to use after appropriate dressing under the rarely earthquake.

Abstract: The BRB has a good seismic energy dissipation effect and it has been proved and applied to many specific projects. In this research, the GH Hotel, a high-rise building in Haikou with the seismic fortification intensity of eight degrees (0.3 g) is selected as a carrier, from which two contrast models of the 40^th story with and without BRB are set up respectively. By Superposition Response Spectrum Analysis and Elastic Time-history Analysis, this study explores the seismic energy dissipation effect of BRB under frequent earthquake in high seismic intensity areas and draws some conclusions.

Abstract: The response of reinforced concrete buildings to earthquake loads can be substantially affected by the influence of infill walls. Also the out-of-plane failure of the infill can cause heavy casualties. In this article, an improved numerical model for the simulation of the in-plane and out-of-plane behaviour of masonry infill is proposed. First, the proposed model is presented. This is an upgrading equivalent strut model composed of two beam-column type elements, with a node at the mid-span assigned a mass in the in-plane and the out-of-plane direction to account for the inertial forces in both directions. Second, the main results of the calibration analyses obtained with two experiments are presented and discussed.

Abstract: To study the effects of seismic waves directions on bridges, the time history analytic method was used. Two bridge types, the railway continuous curved rigid frame bridge and the railway continuous straight rigid frame bridge, have been taken into account. Both the two same span bridges were used for comparative analysis about free vibration and seismic response feature, then some practical application conclusions were obtained. The longitudinal and transversal seismic waves produce the maximum reaction values. Besides, the pier bottom sections and the beam sections at the piers top are the critical sections in the bridges. In addition, this small radius curved bridge can be designed as the straight bridge in seismic design.

Abstract: The self-centering wall including both prestressed tendons and dampers is proposed in this paper, and the corresponding general finite element numerical analysis model, simplified numerical analysis model and theoretical analysis model were established respectively, focusing on how to simulate the prestressed tendons, dampers and the horizontal connection between the wall and the foundation. The numerical simulations of the self-centering wall subjected to reversal loading were performed using the above two numerical analysis models, and the results were compared to those obtained from theoretical analysis. It is indicated that the hysteresis curve of the self-centering wall under reversal loading exhibits flag shape and no residual displacement exists after the wall is unloaded completely. The numerical analysis results match well with those from theoretical analysis, which shows the two numerical analysis models proposed in this paper can be well used to capture the mechanical behavior of the self-centering wall.

Abstract: In this paper, we simulated two-dimension numerical on the strong ground motion through the hybrid scheme based on the pseudo-spectral method (PSM) and finite difference method (FDM). We based on the same focal depth, and 2 different thick deposition layers are used as models to analyze the relationship between site situation and the peak displacement of strong ground motion. The results show that the hybrid PSM/FDM method for seismic wavefield simulation combines with advantages of the pseudospectral method and the finite difference method and makes up for the disadvantage of the pseudospectral method and the finite difference method, so this method can process well the calculation of the discontinuous medium surface, then the calculation accuracy is similar to the pseudospectral method. Through the wavefield simulation it is known that the range of the seismic wavefield the peak ground displacement (PGD) of the thicker deposition is larger and the influence of the secondary surface wave at the basin edge is more obvious. The thicker deposition amplitude of strong ground motion in the basin is larger and the duration is longer, and the reflected wave of which is more obvious and stronger. However, the difference of the site condition has little influence to strong ground motion in the horizontal direction.

Abstract: For estimating seismic response of pier-structure under near-fault ground motion, The typical pulse-type near-fault ground motion records were chosen to establish a record base, and three pier models with different natural period were established; The non-elastic response spectral displacement of ground motion was used to estimate the nonlinear response; The yield displacement of the nonlinear oscillator was defined based on the static pushover analysis result, and its influence on response estimation was studied. The study result is important for structural seismic response estimation by using the non-elastic response spectral displacement and the probability-based seismic performance evaluation.