一种考虑应变率效应的结构非线性时程分析方法

A nonlinear time-history analysis method of structures considering strain rate effect

提出一种在非线性时程分析中考虑材料应变率效应的近似方法:首先,对结构进行不考虑应变率效应的非线性时程分析;然后,根据第一次分析的结果可以得到关键位置在与结构最大顶点位移对应的前1/4循环内的平均应变率,根据这些点的平均应变率对进入非线性构件材料的本构关系进行修正;最后,对结构进行第二次分析。给出了该方法的力学解释,并通过数值模拟对该方法进行了验证。结论:所提出的方法具有较高的精度,可以作为一种在非线性时程分析中考虑应变率效应的有效方法。

A method considering strain rate effect approximately in nonlinear time-history analysis of a structure was proposed here. Firstly, nonlinear time-history analysis of a structure was performed without considering strain rate effect. Secondly, the average strain rates at the key positions in the first 1/4 cycle corresponding to the maximun top displacement were calculated, then the constitutive model of the structure mateial was modified according to the average strain rates of the key positions. Finally, the nonlinear time-history analysis of the structure was performed for the second time. The mechanical explanation of the method was given. Furthermore, numerical simulation was performed to prove the method. The results showed that the method is precise enough to be an effective method to consider strain rate effect in nonlinear time-history analysis of a structure.