Finite Deformation Analysis of Crack Tip Fields in Plastically Compressible Hardening-Softening- Hardening Solids

Abstract

Considering the potential applications of relatively new materials like toughened structural polymers, metallic foams, plastics, transformation toughened ceramics, vertically aligned carbon nanotubes (VACNTs) etc and their limited exploration till now, it appears that there is a need to investigate more about the behavior of such materials under a wide range of loadings. Even though the effect of plastic dilatancy is neglected in classical plasticity theory, the above materials exhibit plastic volume changes and/or pressure-sensitive flow strength. In a recent study, it has been observed that the deformation of the entangled arrays of carbon nanotubes or VACNTs follow elasticviscoplastic constitutive relation which incorporates plastic compressibility, plastic nonnormality and a hardening-softening-hardening type hardness function.