A Sensitivity Analysis of Material Parameters for the Gurson Constitutive Model

Abstract

Following a convincing demonstration of the prediction power of the Gurson model for ductile fracture, it is now required to select realistic material parameters for practical applications of the model. In this paper, using studies on a smooth tensile specimen, a notched tensile specimen, a centre-cracked tensile panel and an analytical cell model, a sensitivity analysis of the material parameters is performed that includes the initial void volume fraction of the primary inclusions and the void volume fraction of the secondary inclusions when fitting the critical void volume fraction. Voids that nucleated from primary and secondary inclusions have been considered separately. It has been found that in either case the selection of material parameters for the finite element analyses is not unique, and the most significant parameter for the predictions is the nucleation burst strain. Some general conclusions concerning the selection of material parameters for the Gurson model have also been made.

Recent Trends in the Development of Gurson’s Model

“…Multi-objective evolutionary algorithms [90] can be used instead to overcome such difficulties. To handle problems of multi-objective optimization, the Pareto optimal solutions can be used, while it is very important to be aware of the non-uniqueness in the constitutive parameters of Gurson-type models [91,92]. A structural design is Pareto optimal, if there is no any other design that satisfies all of the objectives better.…”

Micromechanical modelling of weldments using GTN model

“…They are obviously not fully independent of each other, some experience exists (Zhang 1996;Zhang et al 2000;Thomson et al 2003;Lievers et al 2003) but further detailed studies are necessary to analyse the interaction among them. In general, these parameters are determined by a hybrid methodology of metallographic study, different tensile tests and subsequent numerical analysis.…”

Characterization of debonding strength in steel-wire-reinforced aluminum and its influence on material fracture

“…This is done with tensile test data for the identification of the first eight parameters and shear test data for k x , leading to high effort for the identification process. In addition, the material parameters are non-unique [23], and only one set of parameters allows for a physical-microstructural interpretation. Therefore, narrow boundaries for the parameters are chosen.…”