Computational prediction of fracture toughness of polycrystalline metals
A three-dimensional multiscale computational framework based on the cohesive finite element method (CFEM) is developed to establish relations between microstructure and the fracture toughness of ductile polycrystalline materials.This framework provides a means for evaluating fracture toughness through explicit simulation of fracture processes involving arbitrary crack paths,including crack-tip microcracking and branching.Fracture toughness is computed for heterogeneous microstructures using the J-integral,accounting for the effects of grain size,texture,and competing fracture mechanisms.A rate-dependent,finite strain,crystal plasticity constitutive model is used to represent the behavior of the bulk material.Cohesive elements are embedded both within the grains and along the grain boundaries to resolve material separation processes.Initial anisotropy due to crystallographic texture has a strong influence on inelastic crack tip deformation and fracture toughness.Parametric studies are performed to study the effect of different cohesive model parameters,such as interface strength and cohesive energy,on the competition between transgranular and intergranular fracture.The two primary fracture mechanisms are studied in terms of microstructure characteristics,constituent properties and deformation behaviors.The methodology is useful both for the selection of materials and the design of new materials with tailored properties.
cohesive finite element method crystal plasticity microstructure-fracture toughness multiscale framework
Yan Li David L. McDowell Min Zhou
The George W.Woodruff School of Mechanical Engineering,School of Materials Science and Engineering Georgia Institute of Technology,Atlanta,GA 30332-0405,U.S.A
国际会议
北京
英文
1-8
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）