The Equivalent Elasto-plastic Hysteretic Model of Steel Circular-Tube Bar Elements Considering Compressive Buckling
Xie Dao-qing1, Shen Jin2, Deng Hua1, Zhang Rui1
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1. Space Structures Research Center, Zhejiang University, Hangzhou 310058, China；2. Architectural Design & Research Institute of Zhejiang University, Hangzhou 310027, China
Under strong earthquakes, the failure modes of bars in grid structures are of yielding in tension and buckling in compression. However, the ideal elasto-plastic model conventionally used in seismic computation can not consider the buckling of compressive members. By means of the LS-DYNA software, the ultimate compressive loads, equilibrium paths before and after buckling, and unloading paths of steel circular-tube bars with different slenderness ratios are calculated, and their hysteretic properties under reverse tension-compression loadings are also analyzed. Based on the analysis of the statistical relationships between axial forces, axial elongations and slenderness ratios of these bar specimens, an equivalent elasto-plastic hysteretic model of steel circular-tube bar elements, which can consider both the tensile yielding and the compressive buckling simultaneously, is put forward. This equivalent elasto-plastic hysteretic model is further used in the time-history response computation of an illustrative lattice spherical shell under seldom-occurred earthquake. The result indicates that the failure patterns of members and the distribution of structural weak regions are obviously different from that obtained by ideal elasto-plastic model, and also shows the validity of the equivalent elasto-plastic hysteretic model put forward in this paper.
Xie Dao-qing;Shen Jin;Deng Hua;Zhang Rui.
The Equivalent Elasto-plastic Hysteretic Model of Steel Circular-Tube Bar Elements Considering Compressive Buckling[J]. Journal of Vibration and Shock, 2012, 31(6): 160-165
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