On the Development and Identification of Phenomenological Damage Models - Application to Industrial Wire Drawing and Rolling Processes

Trong Son Cao; Christian Bobadilla; Pierre Montmitonnet; Pierre-Olivier Bouchard

doi:10.4028/www.scientific.net/KEM.554-557.213

Paper Titles

Determination of Flow Curve Using Bulge Test and Calibration of Damage for Ito-Goya Models
p.182

Deep Drawing of Ti6Al4V: Experiments and Modeling over a Wide Range of Strain Rates and Temperatures
p.190

Analysis of the Incremental Forming of Titanium F67 Grade 2 Sheet
p.195

Effect of the Mechanical Parameters Used as Input Data in the Yield Criteria on the Accuracy of the Finite Element Simulation of Sheet Metal Forming Processes
p.204

On the Development and Identification of Phenomenological Damage Models - Application to Industrial Wire Drawing and Rolling Processes
p.213

Optimization Analysis of A7075 Bicycle Stem Forging Process
p.227

Sensitivity Analysis to Optimise the Microstructural Properties of an Inconel 718 Component Manufactured by Rotary Forging
p.234

Application of a Fast Calculation Model for the Process Monitoring of Open Die Forging Processes
p.248

Application of Combined Casting-Forging Process for Production of Durable Lightweight Aluminum Parts
p.264

HomeKey Engineering MaterialsKey Engineering Materials Vols. 554-557On the Development and Identification of...

On the Development and Identification of Phenomenological Damage Models - Application to Industrial Wire Drawing and Rolling Processes

Abstract:

The continuum thermodynamics-based Lemaitre damage model is nowadays widely used to deal with coupled damage analyses for various mechanical applications (e.g. forming process simulations). However, such a model, which only accounts for the stress triaxiality (the ratio between the first and the second invariants of stress tensor) has been found to give incorrect results under shear dominated loading (in terms of damage location as well as risk of crack). Several recent studies have demonstrated the importance of the third stress invariant in damage prediction; the Lode angle parameter is generally used to include it. The idea is to describe completely the stress state in damage model’s formulations, which is defined by the equivalent stress, the stress triaxiality ratio and the Lode angle parameter. This later parameter has proved to have an important influence on ductile damage under low stress triaxiality. Xue’s coupled damage model accounts for the third invariant of the deviatoric stress tensor, allowing a better balance between respective effects of shear and elongation on damage. Some extensions of more physically based damage models, such as the Gurson-Tvergaard-Needleman model, have also been presented to account for this influence of the third stress invariant. In the present work, the phenomenological damage models have been implemented in Forge® Finite Element (FE) software to investigate ductile damage occurring during industrial forming processes. This paper presents the comparative study of Xue’s model and Lemaitre’s model. A complete procedure is detailed to identify the material and damage parameters from experimental mechanical tests on high carbon steel. This identification process has been carried out both for Lemaitre’s coupled damage model and Xue’s coupled damage model. Application to wire drawing followed by flat rolling shows that in such shear-inducing processes, these models predict damage at different locations, due to their different emphasis on shear with respect to elongational strain damage.