构元组集损伤断裂模型及其与内聚区模型的比较  

COMPONENT ASSEMBLING MODEL FOR DAMAGE AND FRACTURE AND ITS COMPARISON WITH COHESIVE ZONE MODEL

作　　者：刘芳[1] 付强 陈岑[3] 梁乃刚[3] 

机构地区：[1]武汉理工大学交通学院,武汉430063 [2]中国轻型燃气轮机开发中心,北京100028 [3]中国科学院力学研究所非线性力学国家重点实验室,北京100190

出　　处：《固体力学学报》2013年第3期241-246,共6页Chinese Journal of Solid Mechanics

基　　金：国家自然科学基金项目(10721202);中央高校基本科研业务费专项资金(2013-IV-021)资助

摘　　要：结构的响应实质上是材料的响应,宏观结构损伤至断裂的发展过程也是材料性质不断演化的结果.构元组集模型从材料的微观物理变形机制出发,基于对泛函势理论和Cauchy-Born准则,抽象出两种构元:弹簧束构元和体积构元.在微观层次上,结构损伤和断裂的实质都是原子间键合力减弱和丧失的结果,而弹簧束构元是同一方向上的原子键的抽象,因此损伤可以通过弹簧束构元的响应曲线来反映.组集两种构元的响应,建立了材料的弹性损伤本构关系,从而能一致描述材料从弹性到损伤、破坏的发展过程.将构元组集模型的本构关系嵌入ABAQUS的用户材料单元子程序UMAT,实现对结构响应的数值模拟.论文模拟了包含中心预制裂纹三点弯曲梁的裂纹扩展过程,并与内聚区模型比较,给出了内聚区模型所假设的应力-位移关系曲线,并从材料损伤演化的角度对材料裂纹扩展过程做出了物理解释.The responses of structures to externally applied loading originate from the materials. The damage and failure process of structure corresponds to the deterioration of materials essentially. With the consideration of the microscopic deformation mechanism of materials, and based on the pair functional potentials and Cauchy-Born rule, component assembling model is developed with two kinds of components,i, e. spring-buddle and cubage com- ponents. Damage and fracture is essentially due to decrease and loss of atomic bonding force in microscopic scale and the spring-huddle component is abstracted from the atomic bonds in the same direction,so damage can be reflected by the force response function of spring-huddle components. Assembling the responses of two kinds of components, the elasto-damage constitutive equations,which can describe the whole deformation process of elastic, damage and failure of materials consistently, are derived. A user subroutine UMAT for this elasto-damage constitutive model is coded in the framework of ABAQUS,and a simulation of three point bending beam with pre-crack is performed to describe the crack propagation process. Compared with the cohesive zone model, the present model not only can predict the stress-displacement curve but also can more clearly and physically explain the crack propagation process.

关 键 词：弹性损伤本构关系 裂纹扩展 ABAQUS UMAT 构元组集模型 内聚区模型 

分 类 号：O346.1[理学—固体力学]