Gross Plastic Deformation vs material definition
Gross Plastic Deformation vs material definition
(OP)
I have problem with practical using of Finite Element Method in header analysis. I would like to use Gross Plastic Deformation (GPD). In this case linear elastic - perfectly plastic material model should be used. Then criterion of failure is 5% plastic strain. Unfortunately I cannot use perfectly plastic material because of problem with convergence. Insted of that I used material with tangent modulus 500MPa. After that I have no problem with convergence. I am thinking whether computed plastic strain (for material with tangent modulus) can be used to check GPD criterion (plastic strain should be less than 5%). What will be difference between computed plastic strain for perfectly plastic material and for material with tangent modulus?






RE: Gross Plastic Deformation vs material definition
One thinks there must be some way to mathematically attack the elastic-plastic model for your case. It is everyday routine for the steel and reinforced concrete structural design, if masked by parctice.
RE: Gross Plastic Deformation vs material definition
Is GPD some kind of code requirement? Do you have to use elastic-perfectly plastic material model (which uses the usual linear elasticity slope to model the linear, then a horizontal slope for the plastic strains), to be conservative? Or can you use whatever elastic-plastic material model fits the data (such as Ramberg Osgood)?
RE: Gross Plastic Deformation vs material definition
RE: Gross Plastic Deformation vs material definition
section B.8.2 where Gross Plastic Deformation method (GPD) is described.