Numerical simulations of void linkage in model materials using a nonlocal ductile damage approximation

Abstract

Experiments on the growth and linkage of 10 urn diameter holes laser drilled in high precision patterns into Al-plates were modelled with finite elements. The simulations used geometries identical to those of the experiments and incorporated ductile damage by element removal under the control of a ductile damage indicator based on the micromechanical studies of Rice and Tracey. A regularization of the problem was achieved through an integral-type nonlocal model based on the smoothing of the rate of a damage indicator D over a characteristic length L. The

Influence of nanovoids in the hydrogen embrittlement fracture of Al–Zn–Mg–Cu alloys

“…Immediately before fracture (8.9% strain), the minimum dNN is 3.2 m. Finite element analysis has revealed that the stress intensity between nanovoids is significantly enhanced when the distance between them is less than five times the nanovoid diameter [51]. As the mean nanovoid diameter is 2.5 × 10 −7 m, dNN must be ≤1.25 m to generate a linkage.…”

Determination of the Constants of GTN Damage Model Using Experiment, Polynomial Regression and Kriging Methods

“…Gunawardena [8] developed a damage model on the basis of Rice and Tracey model. Assuming spherical growth of voids and rigid-plastic behavior of materials, the fracture reference strain ε f is calculated for different states of stress triaxiality as follows:…”

A Review of Damage, Void Evolution, and Fatigue Life Prediction Models

“…Regardless of the different techniques used to characterize the damage evolution with equations and some parameters, it primarily relies on the test data curve to fit the empirical void/damage evolution function. Examples include the Gurson-Tvergaard-Needleman (GTN) model [2], Rice-Tracey model [3], Gunawardena model [4], the well-known, strain rate dependent Johnson-Cook (J-C) damage model [5], some micro-mechanism based damage models, and models using irreversible entropy as a metric with an empirical evolution function. These empirical models are popular for engineering applications due to their simplicity.…”