混凝土断裂行为的损伤仿真模拟!  

Modeling of concrete fracture using a damage model

作　　者：龙渝川[1,2] 何明胜[2] 

机构地区：[1]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045 [2]石河子大学水利建筑工程学院,新疆石河子832003

出　　处：《中国科技论文》2013年第5期417-420,共4页China Sciencepaper

基　　金：国家自然科学基金资助项目(50909109);高等学校博士学科点专项科研基金资助项目(20090191120031);新疆生产建设兵团博士基金资助项目(2012BB013);中央高校基本科研业务费资助项目(CDJRC10200005;CDJZR10200006)

摘　　要：应用基于能量耗散机制的各向异性损伤模型模拟Petersson切口梁试验,进行了软化曲线和网格尺寸参数的敏感性分析,研究了二者对计算精度的影响,以验证该损伤模型在模拟混凝土断裂行为方面的合理性。计算结果显示,软化曲线形状对计算获得的梁试件峰值荷载与峰值后响应影响显著,采用单线性曲线得到的峰值荷载比双线性情况高,其峰值后响应则比双线性情况下降快。粗、细网格计算的结构响应彼此接近,表明采用钝断裂带理论调整应变软化曲线的方法,能够部分消除网格尺寸对计算精度的影响。数值算例说明,采用基于能量耗散机制的各向异性损伤模型模拟混凝土损伤断裂行为,其计算精度能够满足工程要求。An anisotropic damage model was adopted to model a notched beam test. Two stress/inelastic strain relations and finite element meshes were used to conduct the numerical modeling and investigate their effects on the calculation accuracy. The results showed that the stress/inelastic strain relation had a significant effect on the numerical response. The peak load calculated with the linear relation was larger than that obtained with the bilinear one, whereas its post-peak load/deflection relation decreased fas- ter than that obtained with the latter. The responses before peak value obtained with the coarse and fine meshes were in close a- greement because the stress/inelastic strain relation was modified according to the blunt crack band theory to satisfy the conversa- tion of fracture energy. However, the difference in the post-peak response calculated with these two meshes increased gradually, which indicates that the blunt crack theory can partially eliminate the influence of mesh sensitivity. It is concluded that this damage model is applicable to modeling the fracture behavior of concrete.

关 键 词：混凝土 损伤断裂 损伤本构模型 数值仿真 

分 类 号：TU528[建筑科学—建筑技术科学]