A constitutive model based on the evolution and coalescence of elliptical micro-cracks for quasi-brittle materials  

作　　者：NING JianGuo REN HuiLan FANG MinJie 

机构地区：[1]State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China

出　　处：《Chinese Science Bulletin》2012年第28期3773-3781,共9页

基　　金：supported by the National Natural Science Foundation of China (11032002 and 11172045)

摘　　要：Damage and failure of quasi-brittle materials are caused by the evolution and coalescence of micro-cracks.To solve the problem of elliptical micro-crack growth at the elastic deformation stage,a method of complex potential functions is proposed and the effect of the initial orientation on micro-crack growth and deflection is discussed.The critical stress condition for the initial damage is derived according to the criterion of micro-crack growth.Based on energy conservation during wing-crack propagation,a damage constitutive model is developed with the strain criterion created in the condition of micro-crack coalescence.The stress-strain curves of quasi-brittle materials in uniaxial compression obtained based on this model are examined with the experimental results.Damage and failure of quasi-brittle materials are caused by the evolution and coalescence of micro-cracks. To solve the problem of elliptical micro-crack growth at the elastic deformation stage, a method of complex potential functions is proposed and the effect of the initial orientation on micro-crack growth and deflection is discussed. The critical stress condition for the initial dam- age is derived according to the criterion of micro-crack growth. Based on energy conservation during wing-crack propagation, a damage constitutive model is developed with the strain criterion created in the condition of micro-crack coalescence. The stress-strain curves of quasi-brittle materials in uniaxial compression obtained based on this model are examined with the experi- mental results.

关 键 词：损伤本构模型 准脆性材料 微裂纹 椭圆形 合并 基础 演变 裂纹生长 

分 类 号：TU452[建筑科学—岩土工程] TU528.01[建筑科学—土工工程]