Good validation in model, but failure midway. How to fix this failure?
The model contains two parts: a flat punch indenter and a cell below it. It uses the modified honeycomb material (MAT_126) and I have loaded the stress-strain data based on the experimental data obtained of the cells. There is a rigid wall below the cell.
The data seen in the image is the output force (N) vs. displacement (mm) data from the model after being simulated. The model seems to fail at some point in the middle. If I increase the Hourglass coefficient, the model failure gets delayed, but it still does fail and the validation overshoots even further. However, to achieve this later stage of failure, the hourglass coefficient must be larger than recommended values (above 0.15 up to 1). I am confused why this failure is occurring in the first place, when the hourglass coefficient is at lower, suitable values. I have attached a curve file of the force vs displacement results if you would like to check It out and images of the results and post model animation as well.
Current Hourglass type: 4 , Coefficient: 0.15
If any more information is needed, kindly let me know and I will provide it!