Coupled Crystal Plasticity–Phase Field Fracture Simulation Study on Damage Evolution Around a Void: Pore Shape Versus Crystallographic Orientation

Abstract

Various mechanisms such as anisotropic plastic flow, damage nucleation, and crack propagation govern the overall mechanical response of structural materials. Understanding how these mechanisms interact, i.e. if they amplify mutually or compete with each other, is an essential prerequisite for the design of improved alloys. This study shows-by using the free and open source software DAMASK (the Dü sseldorf Advanced Material Simulation Kit)-how the coupling of crystal plasticity and phase field fracture methods can increase the understanding of the complex interplay between crystallographic orientation and the geometry of a void. To this end, crack initiation and propagation around an experimentally obtained pore with complex shape is investigated and compared to the situation of a simplified spherical void. Three different crystallographic orientations of the aluminum matrix hosting the defects are considered. It is shown that crack initiation and propagation depend in a non-trivial way on crystallographic orientation and its associated plastic behavior as well as on the shape of the pore.

Current Challenges and Opportunities in Microstructure-Related Properties of Advanced High-Strength Steels

“…Ideally, the micromechanical simulation tool is embedded into a multiphysics framework to consider additional effects such as temperature fields (due to the inhomogeneous dissipative production of heat during deformation), chemical diffusion (to capture elemental partitioning), damage (which is in many AHSS not triggered by non-metallic inclusions but by specific microstructure features and the associated high micromechanical contrast), and phase transformations (such as for instance the TRIP effect or martensite-to-austenite reversion). [450][451][452][453]…”

Modelling intergranular and transgranular micro-cracking in polycrystalline materials

“…More specifically, different potential cleavage planes are uniquely associated with the grain crystallographic lattice; however, a cleavage plane becomes active, thus evolving into a transgranular crack surface, only if the corresponding resolved tractions fulfil a defined threshold condition, as given by Eq. (7). In this case, a new flat cracking surface is introduced within the grain, thus forming a new interface whose further evolution is governed by transgranular cohesive parameters.…”

“…Polycrystalline materials, which include the majority of metals and ceramics, with several engineering applications, may exemplify the trends sketched above. Polycrystalline materials have been intensely investigated and an increasing level of realism in their virtual modelling has materialised in the transition from two-dimensional (2D) to threedimensional (3D) models [2], in the representation of more realistic grain morphologies [3], made possible by the use of 3D X-ray diffraction micro-tomography [4], in the inclusion of more sophisticated constitutive behaviour for the grains [5,6] and more sophisticated damage and failure mechanisms [7].…”

Solving Material Mechanics and Multiphysics Problems of Metals with Complex Microstructures Using DAMASK—The Düsseldorf Advanced Material Simulation Kit

“…In contrast to the often more quantitative progress, combined multiphysics tools introduce a qualitative step forward in materials modeling as they allow to investigate how different microstructural mechanisms of responding to an applied load can either compete with or mutually enhance each other. Such integrated tools allow to investigate, for example, if a material realizes the prescribed deformation by crystallographic slip or mechanical twinning, how the plastic and elastic anisotropy determines the morphology of second‐phase particles during precipitation, whether a material hardens by deformation or softens by recrystallization, and whether plastic deformation or fracture is energetically more favorable under a given loading scenario . The development of tools capable to integrate these different aspects to get a holistic view of process–structure–property relationships requires joint efforts from specialists in different disciplines and a long history in sustainable software development.…”

“…It has been applied to a wide range of engineering alloys, focusing on crystal plasticity and multiphysics problems. Models range from phenomenological descriptions to physics‐based formulations of dislocation slip, twinning‐induced plasticity (TWIP), martensitic transformations (TRIP), microstructural damage evolution, and the associated temperature evolution . The resulting sets of nonlinear internal‐variable differential equations are solved in a fully coupled way using either FEM or spectral‐based FFT solvers.…”