Finite deformation analysis of crack tip fields in plastically compressible hardening-soft

Finite deformation analysis of crack tip fields in plastically compressible hardening-softening-hardening solids

D.Khan;S.Singh;A.Needleman

【期刊名称】《力学学报：英文版》 【年(卷),期】2017(033)001

【摘要】Crack tip fields are calculated under plane strain small scale yielding conditions. The material is charac-terized by a finite strain elastic-viscoplastic constitutive relation with various hardening-softening-hardening hard-ness functions. Both plastically compressible and plastically incompressible solids are considered. Displacements corre-sponding to the isotropic linear elastic mode I crack field are prescribed on a remote boundary. The initial crack is taken to be a semi-circular notch and symmetry about the crack plane is imposed. Plastic compressibility is found to give an increased crack opening displacement for a given value of the applied loading. The plastic zone size and shape are found to depend on the plastic compressibility, but not much on whether material softening occurs near the crack tip. On the other hand, the near crack tip stress and deformation fields depend sensitively on whether or not material soften-ing occurs. The combination of plastic compressibility and softening (or softening-hardening) has a particularly strong effect on the near crack tip stress