Plastic crack-tip fields under thermoplastic loads

High thermal loading at the vicinity of the crack leaves residual stresses of nonhomogeneous angular distribu-tions around the crack-tip. Since, residual stresses represent a conditional tangent modulus as per elastoplastic criteria for loading or elastic unloading state of stress, thus the pertinent self-similar asymptotic crack-tip fields should satisfy the slip criterion and the associated plasticity material properties.In this paper, the thermoplastic loading on ductile material in the presence of a stationary crack is studied in the sense of minimum-potential self-similar crack-tip fields that satisfy the in-situ stress state (plastic flow rule) and hardening modulus on a patch of points close to the root of the crack and equally distributed in the angular direction.Elastoplastic crack-tip fields for linear hardening materials on residual stress domain are calculated and the relationship between the crack-tip field parameters and the plastic hardening modulus is investigated.The capacity of the Newton-Raphson XFEM formulation to estimate the time dependent order of singularity on the elastoplastic fracture process zone is assessed and a discussion about the feasibility of the elastoplastic crack-tip fields is presented.