常见动态混凝土材料模型基本力学特征对比分析

Comparative Analysis of the Basic Mechanical Characteristics of the CommonlyUsed Dynamic Concrete Material Models

材料本构模型的选择和使用,一直是制约混凝土构件动态损伤模拟技术发展的重要因素之一。基于通用有限元软件LS-DYNA,对其中2种常用的混凝土材料模型(混凝土损伤模型和混凝土连续面盖帽模型)的基本力学行为进行了对比分析。研究结果表明,混凝土损伤模型和连续面盖帽模型在基本应力应变关系、网格敏感性和应变率效应等方面均存在明显的差异。因此,采用这些材料模型进行有限元分析时,必须经过严格的试验验证,特别是在模型校正和后续参数分析时,应采用相同或相近的网格尺寸,以消除网格敏感性的影响。

The selection and application of the material constitutive model has always been one of the mostimportant factors that restrict the development of the damage simulation of concrete members under dynamic loading.Based on the general finite element software LS-DYNA,a comparison and an analysis hare been made of thebasic mechanical behavior of two kinds of commonly-used concrete material models(concrete damage model andcontinuous surface cap model).The experimental results show that there are significant differences in the basic stressstrainrelationship,grid sensitivity and strain rate effect between the concrete damage model and continuous surfacecap model.Hence,there should be a strict experimental verification in the process of the finite element analysis of thematerial model;specifically,in order to eliminate the effects of the grid sensitivity,the same or similar grid size shouldbe used for the analysis of the model validation process and follow-up parameters.