Numerical Reliability in Analysis Method and Modeling for Predicting Critical Behavior of Building Frame Subjected to Strong Ground Motion

本研究的目的是评估数值分析预测框架结构在强震作用下的动力行为，以及精确追踪弹塑性框架结构的平衡路径的可靠性。本文的主要研究成果如下：（1）提出了弹塑性框架静力分析的应变控制策略。对于指定的单元，直接给出其符合本构关系的应变增量。(2)通过对小型钢框架结构振动台试验的验证，表明本文提出的空间梁柱有限元法可以预测空间钢框架结构在强震作用下的倒塌或扭转反应。(3)在对典型体育馆门式刚架结构进行强震作用下的数值分析时，发现在一定的竖向地震动作用下，门式刚架梁端翼缘处的应变反应被显著放大。

The aim of this study is to estimate the reliability of numerical analysis for predicting the dynamic behaviors of building frames under severe earthquake, and for tracing precisely the equilibrium paths of elastic-plastic frames. Major results so far are summarized as follows :(1) Strain-controlled strategy is proposed for static analysis of elastic-plastic frames. For a designated element, its incremental strain consistent with the constitutive law be directly given in this strategy.(2) The verification test to the shaking table test of small steel frame shows that the collapse behavior or twisting response of spatial steel frames under strong earthquake can be predicted by the spatial beam-column FEM proposed in this study.(3) In the numerical analysis of typical gabled roof frame of gymnasium under strong earthquake, it is observed that the strain response at the flange of end of gabled roof beam has been considerably enlarged by a certain vertical ground motion.