X80钢裂纹扩展与失效过程的多尺度模拟与实验验证  

Multiscale Simulation and Experimental Verification of Crack Propagation and Failure Process of X80 Steel

作　　者：盛鹰 贾彬[1,2] 王汝恒[1,2] 钱家钰 邓淞文 SHENG Ying;JIA Bin;WANG Ruheng;QIAN Jiayu;DENG Songwen(School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Sichuan Key Laboratory of Shock and Vibration of Engineering Materials and Structures,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]西南科技大学工程材料与结构冲击振动四川省重点实验室,四川绵阳621010

出　　处：《西南科技大学学报》2021年第4期45-53,共9页Journal of Southwest University of Science and Technology

基　　金：四川省科技计划重点研发项目(2020YFG0183,2020JDTD0021)。

摘　　要：为研究带微缺陷的X80钢的裂纹扩展与失效演化机制,首先在原子尺度建立了多组包含不同微观缺陷的X80钢拉伸微观计算模型,获得了各条包含裂纹尖端演化微观信息的T-S曲线,根据T-S曲线上关键转折点对应的原子构型图,从原子尺度观察分析了X80钢中不同微观缺陷扩展的现象和规律;然后在连续介质尺度建立了包含内聚力单元的单向拉伸CT试件有限元模型,将T-S曲线中反映出的材料核心微观特征引入内聚力模型中作多尺度分析,研究微观缺陷对材料宏观断裂参数的影响程度。结果表明:X80钢钝裂纹、空洞等微缺陷对微观模型裂纹尖端最大应力、微观模型强度的影响程度不同,钝裂纹的影响大于空洞的影响。实验验证了多尺度数值模拟结果的可靠性。For the study of the crack propagation and failure evolution mechanism of X80 steel with microdefects,several sets of tensile microcalculation models of X80 steel with different microdefects were firstly established at the atomic scale,and each T-S curve containing microcosmic information of crack tip evolution was obtained. According to the atomic configuration diagram corresponding to the key turning point on T-S curve,the phenomenon and rule of the different microdefects expansion in X80 steel were observed and analyzed at the atomic scale. Then,a finite element model of uniaxial tensile CT specimen with cohesive force element was established at continuum scale. The key microscopic characteristics of materials reflected in T-S curve were introduced into the cohesive force model for multi-scale analysis,and the influence of different microdefects on the macroscopic fracture parameters of the materials was studied. The results show that the influences of blunt crack and void on the maximum stress at the crack tip and the strength of the micro model are different,and the influence of blunt crack is greater than that of void. Experiments verify the reliability of multi-scale numerical simulation results.

关 键 词：X80钢 微缺陷 T-S曲线 内聚力模型 

分 类 号：O341[理学—固体力学]