Numerical and analytical introduction to the prediction of grain boundary micro-crack initiation induced by slips bands impingement.Effect of material and microstructure parameters
Micro-cracks are often observed at the intersections of thin slip bands (SB) and grain boundaries (GB) due to local stress concentration.Numerous models are based on the pile-up theory and the Griffith criterion,used since the pioneering work of Stroh.We have shown that the former underestimate strongly the macroscopic stress for GB micro crack nucleation.In fact,the key issue is that slip bands display finite thickness,observed to belong to 20nm 1000nm.Therefore,one aims to account for the effect of SB thickness in crystalline finite element (FE) calculations performed using the Cast3M software.The simulations take into account the effects of isotropic elasticity parameters,cubic elasticity,GB orientation and crystallographic orientation of the considered grain.Following the theory of matching of asymptotic expansions,this leads to an analytical expression of the GB normal and shear stress,which show weaker stress singularities than the pile-up one.
Micro-cracks slip bands pile-up theory linear fracture mechanics FE method crystalline plasticity
Mohamed Ould Moussa Maxime Sauzay
CEA,DEN,DANS,DMN,SRMA,F-91191 Gif-sur-Yvette,France
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）