力法非线性梁柱单元的合理单元长度划分

发布时间：2018-11-13 17:44

【摘要】：针对目前结构非线性分析中最常用的力法非线性梁柱单元模型,从理论上分析出了能消除其计算失真问题的合理单元长度及对应积分点数量。然后基于OpenSees有限元程序,使用该理论分析结果建立了一组单墩循环推倒试验的数值分析模型,通过加载点力-位移滞回曲线的对比分析和墩底截面曲率滞回曲线的对比分析验证了理论结果的正确性。结果表明:使用力法非线性梁柱单元模型进行结构的非线性数值分析时,其单元长度划分应根据积分点数量确定,确定原则应基于使单元屈服后变形增长的分布长度与塑性铰长度相等进行计算;在实际使用中,可利用等效塑性铰长度计算积分点数量与单元长度的关系,初步确定单元划分的合理长度;在保证单元长度与积分点数量的对应关系前提下,力法非线性单元的积分点数量越多,计算结果越稳定。
[Abstract]:Aiming at the most commonly used force method nonlinear Liang Zhu element model in nonlinear analysis of structures at present, the reasonable length of element and the corresponding number of integral points can be analyzed theoretically to eliminate the problem of calculation distortion. Then, based on the OpenSees finite element program, a set of numerical analysis models of cyclic push-down test of single pier are established by using the theoretical analysis results. The correctness of the theoretical results is verified by the comparative analysis of loaded point force-displacement hysteretic curves and the comparative analysis of curvature hysteretic curves at the bottom of piers. The results show that when the nonlinear Liang Zhu element model of force method is used for nonlinear numerical analysis of structure, the division of element length should be determined according to the number of integral points. The determination principle should be based on the calculation of the distribution length of deformation growth after the yield of the element is equal to the length of plastic hinge. In practical use, the relationship between the number of integral points and the length of element can be calculated by using the length of equivalent plastic hinge, and the reasonable length of element partition can be preliminarily determined. On the premise of ensuring the corresponding relation between the length of the element and the number of integral points, the more the number of integral points in the nonlinear element of force method is, the more stable the calculation results are.
【作者单位】：同济大学土木工程防灾国家重点实验室;
【基金】：国家自然科学基金项目(50878147,51278375) 国家重点实验室项目(SLDRCE10-B-09)
【分类号】：U442.55

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