三种梁柱单元在结构非线性分析中的精确性比较研究

Accuracy comparison research of three nonlinear elements for structural nonlinear analysis

预测结构在罕遇地震作用下的非线性行为是结构基于抗震性能设计和评估中的关键问题,而其首要问题在于解决结构构件的非线性分析模型问题。本文介绍了结构非线性分析中三种常用的宏观单元模型,即基于刚度法的梁柱单元(DB)、基于柔度法的梁柱单元(FB)以及基于柔度法的塑性铰单元(PH)模型。基于PEER柱子试验数据库,将三种单元数值模拟结果与相应的试验结果进行对比,并以峰值强度之比、初始刚度之比和能量耗散能力之比三个指标统计评估了三种单元数值模拟的精确性。研究结果表明,PH单元计算结果的初始刚度之比和能量耗散能力之比均好于DB和FB单元,三种单元计算结果的峰值强度之比较接近,PH单元模拟精度最好。

Predicting structural nonlinear behaviors under rare earthquake is the key issues of performance based on structural design and evaluation,and the most important issue lies in getting resolved of structural nonlinear models. Displacement-Based（ DB）,Force-Based（ FB） and Plastic Hinge（ PH） elements which are commonly used in macro-fiber element models of structural analysis are introduced in this paper firstly. Based on PEER column test database,numerical simulation results of the three elements are compared with test results,and the accuracy of elements is evaluated statistically according to the peak strength ratio,initial stiffness ratio and energy dissipation capacity ratio of the global responses. The research demonstrates that initial stiffness ratio and energy dissipation capacityratio of PH element are the best of the three elements,and the peak strength ratios of three elements are about the same values. PH element is the most accurate element.