There are 2 approaches for this. The first one is purely testing the numeric:
Attached a simple compression model. It is friction free and without thermal effects (constant 1000°C in the example). This results into a uni-axial stress strain relation ship, which is simple to analyze. The press velocity is defined based on:
velocity = initial_height*phip*exp(-phip*time) with phip being the desired strain rate.
With this the strain rate remains constant through out the process. In the example 5 1/s.
Thus we have constant and uniform temperature and strain rate as well as uniform plastic strain and equivalent stress, with the equivalent stress being equal to the Z normal stress and to the contact pressure (in the simulation within the numerical accuracy of time and mesh discretisation and convergence reached).
In this condition the Effective Plastic Strain equals ln(current_height/initial_height). Let's just use absolute values for now. Measure the height in the results and compare with the simulation result --> validate.
As said, with the math we use ensures that the equivalent stress equals the flow stress of the material during plastic deformation. Take the Effective Plastic Strain from the results (or the calculation before), consider the temperature and the strain rate set in the model and compare the Equivalent Stress from the results. Compare with the flow curve in the material data --> validate.
The force on the dies (the press force) is contact_pressure*contact_area. With
you get the current press force as a function of the current stroke and the current contact pressure. The current contact pressure is already validated with the flow stress above and the plastic strain at the top. Compare the calculated fore using this formula and compare with the simulated force --> validate.
There are 2 approaches for this. The first one is purely testing the numeric:
Attached a simple compression model. It is friction free and without thermal effects (constant 1000°C in the example). This results into a uni-axial stress strain relation ship, which is simple to analyze. The press velocity is defined based on:
velocity = initial_height*phip*exp(-phip*time) with phip being the desired strain rate.
With this the strain rate remains constant through out the process. In the example 5 1/s.
Thus we have constant and uniform temperature and strain rate as well as uniform plastic strain and equivalent stress, with the equivalent stress being equal to the Z normal stress and to the contact pressure (in the simulation within the numerical accuracy of time and mesh discretisation and convergence reached).
In this condition the Effective Plastic Strain equals ln(current_height/initial_height). Let's just use absolute values for now. Measure the height in the results and compare with the simulation result --> validate.
As said, with the math we use ensures that the equivalent stress equals the flow stress of the material during plastic deformation. Take the Effective Plastic Strain from the results (or the calculation before), consider the temperature and the strain rate set in the model and compare the Equivalent Stress from the results. Compare with the flow curve in the material data --> validate.
The force on the dies (the press force) is contact_pressure*contact_area. With
you get the current press force as a function of the current stroke and the current contact pressure. The current contact pressure is already validated with the flow stress above and the plastic strain at the top. Compare the calculated fore using this formula and compare with the simulated force --> validate.
