Applied Mechanics and Materials Vols. 580-583

Abstract: The control parameter of shaking table is one of the key elements which significant influence on the system control performance. An algorithm which uses the model of system identification to theoretically calculate the control parameter is put forward, and then obtains the optimal three-parametric control parameter based on theoretical calculation. Tuning algorithm can get more ideal control parameter and could be applied in shaking table TVC parameter self-tuning.

Abstract: Infilled wall is always regarded as a nonload bearing element, its energy-dissipation capacity and impact for the frame structure under earthquake have not been taken seriously. In this paper the function of infilled wall for frame structure was discussed, energy-dissipation capacity of different measures were analysed and compared from the point of passive control theory. This paper provides the reference for the further research of filler wall.

Abstract: With the project case, the seismic performance of girder transfer floor member and the plate transfer floor member were discussed. Contrast calculation was carried out in girder transfer floor member and the plate transfer floor member with SATWE method to analyze its reasonable and unreasonable places. Based on overall structure calculation of a high rise building, the seismic design requirements for buildings applying thick transferring plate have been presented. The conclusion is that the seismic performance of girder transfer floor member is more advantageous and affordable, more convenient and more economical in ingredients.

Abstract: This study is aimed to analyze the ultimate state of bridges with rocking isolation of spread foundations under extreme earthquakes. The Vector Form Intrinsic Finite Element method (VFIFE) is adopted to simulate the failure procedure of bridges with and without rocking isolation. To simulate the highly nonlinear behaviors between soil and foundations, Winkler-based models are established in the VFIFE in this study. A practical five-span bridge with spread foundations is chosen to study the effect of rocking isolation and discuss the influence of altering parameters of bridges. The analytical results are compared between linear soil springs and nonlinear soil springs. Furthermore, the ultimate state of bridges is simulated to realize the dynamic behaviors of bridges under extreme earthquakes.

Abstract: LSSRLI-1 is an equivalent linear program which is used for seismic ground response analysis. Since the LSSRLI-1 was proposed by Xiaojun Li in 1989, it played very important role in seismic safety evaluation, solved the inputting problem for dynamic response analysis of structure. Some deficiency was found in the practice, especially when the layered site is soft. Linear exact solution is deduced in the frequency domain.based on the engineering wave theory. A program is compiled in the MATLAB environment, which is used to compare with the LSSRLI-1 results, including the ground response spectrum and the soil strain distribution.

Abstract: In order to improve the solution of nonlinear time-history analysis for high-rise buildings, the concrete constitutive relation of Chinese code has been modified by using Najar damage theory, and based on the limitation of stable time increment in explicit dynamic analysis, a simplified Rayleigh damping form with tiny stiffness proportional damping is proposed to decrease the damage induced by those high frequencies, at last, the influence of mesh size on stress and damage is also discussed. The numerical results show that these principles are workable for more accurate results.

Abstract: The deamplification model developed by Zendagui et al. has been adapted in this study for the case of P₁ wave propagation in porous media in order to investigate the effect of saturation degree on motion coherency at depth. The input wave amplitude distribution function is generated compatibly with the suitable free field coherency model and the top wave amplitudes are evaluated using the transfer matrix method following the Biot’s theory. The results show that even if the saturation degree decreases slightly below the complete saturation, it influences the coherencies of horizontal and vertical motion due to P₁ wave incidences. Elsewhere, the generation process shows that in this case, the wave front content, necessary to produce a coherency identical to the Luco and Wong model at the free field, is more focus with less intensity than required in the case of a complete saturation.

Abstract: Based on nonlinear precise integration method, two new numerical integration methods of pseudo-dynamic test of structures are presented. One is explicit predict-correct, four order accuracy and multistep method avoiding calculating the inversion of the state matrix. The other is implicit predict-correct, four order accuracy and multistep method that need calculate the inversion of the state matrix. Since their accuracies are superior to the central difference method by enlarging time step and their stabilities are better, the structural systems of multi-degree of freedom could be well tested and the testing work would be largely reduced. Finally, a pseudo-dynamic test of combined tube structure has been executed with the explicit multi-step method.

Abstract: The performance-based engineering approach, as opposed to prescriptive rules of code-based design, is based on simulation of real structural behavior. Reliability of the expected performance state is assessed by using various methodologies based on finite element nonlinear static pushover analysis and specialized reliability software package. Reliability approaches that were considered included full coupling with an external finite element code based methods in conjunction with either first order reliability method or importance sampling method. The building considered in the actual study has been designed against seismic hazard according to the Moroccan code RPS2000.

Abstract: This paper proposes an energy dissipation device based on shape memory alloys (SMA) for frame structures. By setting anchorage device below and near the inflection point of the first storey columns, a set of force cable and energy dissipation cable using SMA are installed symmetrically in the anchorage device and the bottom of them fixed in the ground. Analytical study including the push-over and time-history analysis were investigated by ANSYS finite element program to a new CFST frame and an ordinary CFST frame. Studies have shown that the device can effectively control the structural displacement response and acceleration response, dissipating large amounts of earthquake energy. Therefore, the energy dissipation devices had a better value and prospects in engineering.