基于多尺度特征应变均匀化计算HCP多晶体塑性  

Eigen-strain-based multiscale homogenization application for HCP polycrystalline plasticity

作　　者：刘洋 朱祎国 胡平[1] LIU Yang;ZHU Yi-guo;HU Ping(School of Automotive Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]大连理工大学汽车工程学院

出　　处：《计算力学学报》2019年第4期536-541,共6页Chinese Journal of Computational Mechanics

基　　金：国家重点基础研究发展计划(2010CB832700)资助项目

摘　　要：结合基于位错密度的晶体塑性模型与特征应变均匀化方法来分析HCP晶体结构材料的力学行为,拟开发一种计算模型用于有效捕捉以及预测微观与结构尺度的裂纹产生。首先,与传统的晶体塑性有限元相比,该多尺度模型可以提高计算效率并同时保持微观尺度的捕捉精度。其次,将模型与试验结果的差值为优化目标,在满足物理学定义的条件下得到合理的材料参数。最终,结构尺度的模拟显示该模型可以获取在结构尺度与微观晶粒尺度的潜在裂纹生长区域。A dislocation density based crystal plasticity method is applied with the eigen-strain-based homogenization to investigate the thermo-mechanical responses in titanium alloys.The objective of our study is to devise a computational model that could efficiently track and predict the crack initiation at both micro-and structural-scale.First,the proposed model is compared with the classical crystal plasticity finite element method,which shows its improvement of efficiency while retaining the accuracy in describing the response at micro-scale.Second,the parameters are obtained within the physical range and the error between simulation and experiment is treated as the optimization objective for the calibration.Finally,a structural-scale simulation shows that the proposed model can pinpoint the potential crack initiation sites throughout the structure and at grain level accuracy.

关 键 词：晶体塑性 特征应变 均匀化 密排六方晶体 

分 类 号：O344.1[理学—固体力学]