Applied Mechanics and Materials Vols. 438-439

Abstract: In this paper, the shaking table test of a 1/6 scale multi-rib composite wall supported on frame was conducted. The test structure has undergone elastic stage and cracking up the whole process of destruction, the dynamic characteristics of the structure in the various stages of change and the dynamic response were recorded. The shaking table test was in two steps, the first step for modal testing, modal test results such as period and damping; the second step was the seismic test to measure the dynamic characteristics of the test structure, acceleration response and displacement reaction to study the bottom frame ribbed composite wall structure under strong earthquake laws of failure and collapse failure criterion.

Abstract: Buildings on the slope are widely used and have been increasing in mountainous city. The object of this study is to study the influence of masonry infill on the seismic characteristics of RC frames on slope. The concept of slope building is introduced, and the proposed infill model is presented. It is a single equivalent strut model with the compression and tension behavior. The proposed infill model uses the energy-based cyclic degradation law to simulate the deterioration of the infill during the seismic action. In the Part (II) of the paper, the infill model is calibrated, and the performance of different reinforced concrete two bay-frames, bare and infilled, subjected to eight seismic motions was investigated.

Abstract: Slope structure means a structure built on a slope in the mountainous region. The aim of this study is to study the influence of masonry infill on the seismic characteristics of RC frames on slope. First, the main results of the calibration analyses using the infill model introduced in the Part (I) of the paper are presented. Second, the performance of different reinforced concrete two bay-frames, bare and infilled, subjected to eight seismic motions were investigated. The results show that if the infill is built correctly in all storeys, it gives a significant contribution to the energy dissipation capacity by reducing the dissipation energy demands in frame elements and decreasing significantly the maximum displacements. Therefore the contribution of masonry is of great importance.

Abstract: Since the Wenchuan earthquake in 2008, the earthquake-resistant consideration in structure design is highlighted in the Chinese code. This paper introduces a dynamic elasto-plastic method in structure modeling using ABAQUS finite element analysis. In the first stage, structural models are transferred into ABAQUS INP files. Then the user subroutines are given to describe the elastic and plastic behaviors of both concrete and steel materials. Finally, the models are analyzed in an ABAQUS implicit or explicit analysis. The result can suggest the weakness of the building and provide advisement in reinforcing the structure.

Abstract: Non-convergence often occurs in the solution of highly nonlinear problem by conventional implicit finite element method. As another choice, explicit method is sometimes used by researchers. Through 2 typical static and dynamic examples this paper verifies that explicit finite element method can provide the same exactness of calculation as the implicit method even in the situation that the duration of action exceeds the natural period of structure greatly. At the same time, compared with implicit method, explicit method possesses higher speed, more robust algorithm, and stronger nonlinear capability, so that explicit method can be applied in static and dynamic analysis of structures, especially in large deformation and highly nonlinear problem.

Abstract: Based on the discussion of mechanical characteristics of frame shear-wall structure, the shear-wall is identified as the key component resisting seismic action. In view of the structural design requirements such as reliability and economy, the arrangement, amount and structural details of shear-wall is analyzed and proposed. The research may provide a good reference for engineers to reasonably design the frame shear-wall structure.

Abstract: To the asymmetric-plan structures, the torsion model is obvious, and the influence of input angle of excitation on structural response is sensitive, so a practical response spectrum method for analyzing the behaviors of this kind of structure is studied. Based on the achievements about the multi-components accelerations power spectra matrix, a rational formula, considering the input angle of excitation, is deduced by using stationary random vibration principle. A practical formula is proposed by introducing displacement response spectrum as equally as to considering the non-stationarity of excitation.

Abstract: Shanghai Pudong Shangrila Hotel extension project is a super-high frame-shear wall structure. In this paper, a concrete uniaxial hysteresis constitutive model and a practical elastic plastic damage constitutive model are introduced, both of which are established by the author before, and then both models are developed in ABAQUS via UMAT, and used to simulate Shanghai Pudong Shangrila hotel extension engineering. The numerical model is established in PKPM and then be converted to ABAQUS, in which fiber model is used to simulate the frame elements and sell model is used to simulate shear-walls. Through numerical simulation, we can see that the simulation results and test results are coincided well, which proved that the proposed constitutive models is effective in analyzing large complex structures, and the selected element models are reasonable.

Abstract: The seismic spectral computation of structures is time-consuming under multiple-support excitations. The seismic spectral response of structures can be expressed based on several correlation coefficients and the time consumption can be greatly reduced if the coefficients are expressed in closed-form. In this paper, approximate expressions of spatial coherence functions are suggested. Then integrals for the coefficients are carried out analytically and their closed-form expressions are obtained. The closed-form expressions are developed from Clough-Penziens APSD and Hus APSD. The numerical results show that the approximate closed-form expressions of correlation coefficients are of enough engineering accuracy and high efficiency.

Abstract: By means of questionnaire survey, this paper investigates seismic performance of 210 self-built houses in rural areas of Henan Province, analyzes the survey results and puts forward suggestions for self-built house earthquake fortification.