A simple member model for inelastic earthquake response analysis of three-dimensional steel frames with large deformation

1.提出了一种简单的数值分析方法--“非弹性节理模型”，“的方法，该方法能够跟踪钢构件在变组合应力作用下的弹塑性行为。钢构件的受力性能可以简单地用多个单轴非弹性弹簧来表示。2.将钢构件看作是由两种单元组成的组合体：一种是弹性梁单元，另一种是多弹簧非弹性节点。非弹性节点由若干个非弹性轴向弹簧、剪力板和扭簧组成。假定非弹性弹簧的骨架曲线为三线型。这里的非弹性弹簧采用了“泊松-位移模型”。提出了一个可根据现有的钢筋单轴循环加载试验资料合理设计的位移系数。采用“非弹性位移模型”，可以方便地考虑节点的屈服、应变硬化、局部屈曲引起的应力退化、包辛格效应和复杂的滞回特性。3.讨论了节点非弹性模型参数的取值问题。这些参数可根据材料试验和压弯构件的单调弯曲试验确定合适的取值。编制了增量分析程序。4.通过对变轴力和变弯矩幅值的压弯构件加载试验的模拟，验证了数值分析方法的有效性。数值分析结果与荷载试验结果吻合较好，特别是在循环荷载试验和地震荷载试验中。

1.A simple numerical analysis method called 'inelastic joint mode., ' which is able to trace the inelastic behaviors of the steel members subjected to varying combined stress, is developed in this research. The behaviors of steel members can be simply demonstrated with several uni-axial inelastic springs.2.The steel members, are regarded as an assembly of two kinds of elements : one is an elastic beam element and the other is multi-spring inelastic joint. The inelastic joint is composed of several inelastic axial springs, shear panels and torsional spring. The skeleton curve of the inelastic spring is supposed to be the tri-linear type. A 'skeleton-shift model' is used for the inelastic springs here. A skeleton-shift factor is proposeded, which can be properly designed according to the available test data of uni-axial cyclic loading test of steel bars. By using the 'skeleton-shift model', the yielding, strain-hardening, stress degeneration caused by local bucking, the Bauschinger effect and the complicated hysteresis behavior can be easily considered.3.The appreciation of the parameters of the inelastic joint model is discussed. These parameters can be given proper values according to the material tests and the monotonic bending tests of beam-columns. An incremental analysis program is developed.4.The validity of the numerical analysis method is checked by the simulation of the loading tests of beam-columns subjected to varying axial load or varying grandience of moments. Numerical analysis results show good agreement totally with the loading tests, especially in the case of cyclic loading tests and earthquake loading tests.