Greetings,
I have been using ASM 2014 to model impact of a rock (similar to granite) on a steel plate structure. I am using MES for this. As well as stress and deflection, I am interested in obtaining the impact force.
The model has been running reliably so no problems there. The results appear generally as you would expect.
I have been setting the element definition to isotropic for both rock and steel. I intend to change the steel to a non linear von mises model to allow for yielding becausae the stress results are well into the yielding regime.
I have used mostly 8 node bricks with some 20 node bricks where necessary.
I am using a surface to surface contact.
The rock is modelled as a sphere. I have selected granite as a material.
To obtain impact forces, I have used the x and y reactions -> inquire results->sum technique. (first I selected the nodes in the contact region of the rock). I then combined the x and y reactions to get a resultant reaction as the plate is inclined to the x-axis)
The forces and stresses however, seem higher than expected.
I have 5 basic questions:
1. What should i set the rock element definition to? It is highly likely that the rock will fracture near the point of impact.
2. What sort of accuracy can I expect wrt stress and impact forces?
3. Is the technique for impact force calculation correct? I am wondering about the correct selection of the nodes.
4. Are there any good references for modelling impacts of this type?
5. Are there any ways to check these results?
Regards,
Tim
Hi Tim,
Here are my opinions to your 5 questions.
Good luck. Let us know how it turns out.