Applying ductile damage and damage evaluation for tensile test specimen

[Supun93]

Recently, i have model a tensile test on abaqus applying elastic and plastic properties. And the FEM results were very accurate. I'm wondering how to apply the ductile damage and damage evaluation to this model.

 

[FEA way]

Among various damage models available in Abaqus there is a ductile damage initiation criterion. It can be specified in CAE using material editor: Mechanical —> Damage for Ductile Metals —> Ductile Damage. There you have to specify equivalent plastic strain at damage initiation and its dependence on stress triaxiality and strain rate (optionally also temperature and predefined field variables). To define this in the input file use *Damage Initiation, criterion=Ductile.

Damage evolution for ductile metals can be defined in the same window. Select Suboptions —> Damage Evolution and choose the type (Displacement or Energy). For the first type you have to provide the value of effective plastic displacement at failure (measured from the time of damage initiation). For the second type specify the value of fracture energy. This can be also defined in the input file using *Damage Evolution, type=Displacement or *Damage Evolution, type=Energy.