板件宽厚比对高层钢结构压弯构件滞回性能的影响

根据能量等效性假设及热力学第二定律，推出损伤材料的弹性本构方程；采用混合强化准则，考虑Bauschinger效应、屈服平台、硬化(软化)效应及损伤和损伤演化影响，建立了结构钢弹塑性各向异性损伤本构关系．结合构建的本构关系，采用八节点超参数壳体单元，推导了用U．L．格式及Cauchy应力描述的板壳双重非线性有限元方程，并编制了计算程序．分析了翼缘宽厚比、腹板高厚比对工形截面钢压弯构件滞回性能的影响，提出了压弯构件板件宽(高)厚比限值公式及相关公式．

Effects of the plates width-thickness ratios on cyclic characteristics of I-section steel beam-columns

The elastic anisotropic damage model is put forward based on the hypothesis of energy equivalent and the second law of the thermodynamics. The elasto-plastic anisotropic damage model of the constructional steel is also proposed, which involves the mixed hardening criterion, Bauschinger effect, yield plateau, hardening (softening) influence, damage and damage evolution. Based on the constitutive model of the constructional steel and the 8-node degenerate shell element, the updated Lagrange (U.L.) formulations for FEM analyses are derived. After developing and debugging program, the method of double nonlinear shell FEM is adopted to analyze the I-section steel beam-columns under the action of cyclic loads. The interaction formulas of the plate's width-thickness ratios of the I-section steel beam-columns under the action of cyclic loads are established.