有限单元柔度法考虑剪切变形的纤维单元模型

Fiber element model of flexibility- based finite element method considering shear deformation

基于有限单元柔度法的梁柱单元模型,以单元力的形函数为出发点,其优点是单元内部截面力场的分布总能满足平衡条件。但目前国内外学者提出的梁柱单元模型,还不能考虑剪切变形对构件刚度的影响。建立了基于有限单元柔度法的弹塑性纤维单元模型,考虑了剪切变形和几何非线性的影响,适用于钢筋混凝土短柱、剪力墙等较大截面杆件的分析研究。依据单元模型编制了非线性有限元分析程序,进行了低周反复荷载试验的数值模拟。模拟分析结果反映了结构构件的主要受力特征,并与实验结果具有良好的一致性。

Finite element （FE） flexibility method-based beam-column element model takes shape function as start- ing point and its advantage is that the force field distribution on cross-section inside element always satisfies equilibrium condition. But the beam-column models formerly developed at home and abroad could not take the shear deformation of the element into account. FE flexibility-based elastoplastic fiber element model considering shear deformation and geometric nonlinearity was set up in this paper, which extends the application of flexibility-based finite element method to beam-column members with small slenderness ratios such as shot column and shear wall. Nonlinear FEA program was compiled, some low-cyclic loading tests were simulated. The results reflect the basic aseismic property of the members, and agree well with the actually measured ones.