A Computational Model for Intergranular Stress Corrosion Cracking

• Main Author: Rimoli, Julian Jose
• Format: Others
• Published: 2009
• Online Access: https://thesis.library.caltech.edu/1808/3/Julian_Rimoli_Thesis.pdf; https://thesis.library.caltech.edu/1808/1/CrackEvolution.avi; https://thesis.library.caltech.edu/1808/2/GB_Relax.avi; https://thesis.library.caltech.edu/1808/4/PlasticStrain.avi; Rimoli, Julian Jose (2009) A Computational Model for Intergranular Stress Corrosion Cracking. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/K1HJ-DZ56. https://resolver.caltech.edu/CaltechETD:etd-05142009-135909 <https://resolver.caltech.edu/CaltechETD:etd-05142009-135909>

Stress corrosion cracking (SCC) is a very common failure mechanism characterized by a slow, environmentally induced crack propagation in structural components. Time-to-failure tests and crack-growth-rate tests are widespread practices for studying the response of various materials undergoing SCC. However, due to the large amount of factors affecting the phenomenon and the scattered data, they do not provide enough information for quantifying the effects of main SCC mechanisms. This thesis is concerned with the development of a novel 3-dimensional, multiphysics model for understanding the intergranular SCC of polycrystalline materials under the effect of impurity-enhanced decohesion. This new model is based upon: (i) a robust algorithm capable of generating the geometry of polycrystals for objects of arbitrary shape; (ii) a continuum finite element model of the crystals including crystal plasticity; (iii) a grain boundary diffusion model informed with first-principles computations of diffusion coefficients; and (iv) an intergranular cohesive model described by concentration-dependent constitutive relations also derived from first-principles. Results are validated and compared against crack-growth-rate and initiation time tests.