The Void Growth Model (VGM)Expanding on the derivations of Rice and Tracey (1969) = > (1)Where, m and e are the mean and the effective stress, p d is the incremental equivalent plastic strain, and critical VGI is a material parameter that quantifies the critical void ratio.The critical void growth index critical VGI increases with material toughness and indicates a more ductile material.
An enhanced void-crack-based Rousselier damage model for This modelling strategy, so-called Rousselier-UMAT-XFEM (RuX) model, is proposed to connect both concepts, which gives an advantage in predicting the material behaviour of ductile material in terms of voids and crack relation. This is the first contribution where XFEM is used in ductile fracture analysis for micromechanical damage problems.
A model for the axisymmetric growth and coalescence of small internal voids in elastoplastic solids is proposed and assessed using void cell computations. Two contributions existing in the literature have been integrated into the enhanced model. The rst is the model of Golo-ganuLeblondDevaux, extending the Gurson model to void shape
Analysis and design of dual-phase steel microstructure for Our experimental observations show that the mechanism of ductile fracture in these two DP steels involves nucleation, growth and coalescence of micron scale voids. We thus employ microstructure-based finite element simulations to analyze the ductile fracture of these dual-phase steels.
Calibration Procedures for a Computational Model of Calibration Procedures for a Computational Model of Ductile Fracture of void growth under axisymmetric stress states. The extension  does not alter the model for these states. The extension modifies the predictions for states with non-zero (). In particular, a contribution to damage growth under pure shear stress states is
The fracture failure of high-strength steel has an important relationship with the stress state. In order to predict the fracture failure of high-strength steel under different stress conditions, based on the void growth model (VGM), a fracture model which comprehensively considers the effect of stress triaxiality and the Lode parameter on fracture failure is proposed and is called LVGM.
Fracture strain model for hydrogen embrittlement based on Sep 21, 2020 · The proposed model applied multi-axial fracture strain based ductile damage evolution law coupled with HELP mechanism to evaluate hydrogen accelerated micro-void coalescence (MVC) fracture. Void growth and coalescence were described by hydrogen enhanced plastic strain and hydrogen reduced fracture strain.
Micromechanics-based model for trends in toughness of void growth and coalescence, and the effort here is to relate fracture toughness to details of the microstructure such as void volume fraction, void shape and void distribution. Fig. 1 depicts the model envisioned for address-ing the cracking in ductile metal failing by the void growth mechanism. The initial geometry is a pre-
void growth ratio (R/R0)c, as the maximum value of (R/R0), obtained according to the Rice-Tracey model. The critical void growth ratio value was then used for the analysis of crack growth initiation in CT25 specimen, as the further step in the scope of numerical modeling of ductile fracture
Optimal scaling laws in ductile fractureBackground on ductile fracture . brittle ductile (Courtesy NSW HSC online) Fracture surface in SA333 steel, room temp., d/dt=3×10-3. s-1 (S.V. Kamata, M. Srinivasa and P.R. Rao, Mater. Sci. Engr. A, 528 (2011) 41414146) Ductile fracture in metals occurs by void nucleation, growth and coalescence Fractography of ductile-fracture
Study on the formation of micro-voids during ductile fractureJan 12, 2018 · Ductile fracture of engineering materials is a primary model for material failure occurring when voids nucleate, grow and coalesce . In general, the observation from fractographs showed the growing and coalescing of mass of micro-voids, which was difficult for the formation of micro-voids