Parameters Identification for GTN Model and Their Verification on 42CrMo4 Steel

Abstract

The base of this paper is exact measurement of deformation and fracture material characteristics in laboratory, evaluation of these parameters and their application in models of finite element analysis modelling the fracture behaviour of components with defects. The base of the work is dealing with ductile fracture of forget steel 42CrMo4. R-curve is modelled by 3D FEM using WARP3D and Abaqus. Crack extension is simulated in sense of element extinction algorithms. Determination of micro-mechanical parameters is based on combination of tensile tests and microscopic observation. Input parameters for the next computation and simulation were received on the base of image analysis, namely fN and fo. The possibility of transferring these parameters to another specimen is discussed.

Cohesive Zone Model and GTN Model Collation for Ductile Crack Growth

“…The basic micromechanical parameters for GTN model were determined from the measured tensile test data combined with the finite element calculations; generally 9 material parameters have been determined as described elsewhere [3]. The geometry parameters q 1 , q 2 , q 3 were used to adjust the model, f c is the critical void fraction for coalescence, f F is the final value of void fraction, f N is the nucleation parameter, in all computations recommended values for nucleation were used (ε N =0.3 and S N =0.1).…”

Modelling of Fibre-Matrix Interface of Brittle Matrix Long Fibre Composite by Application of Cohesive Zone Method

“…Thanks to phenomenological character of cohesive models this model is adapting for various kinds of materials and damages. Cohesive models (more often) cohesive zone model (CZM) is increasingly being used to simulate fracture and fragmentation processes in metallic, polymeric, ceramic materials and composites [2]. Base principle of CZM which is using cohesive elements for crack and damage modelling is their damage while the classical continuum elements are undamaged.…”