Exaggerated reaction forces: Openradioss explicit dynamic

Andrea

Hi everyone,

I am relatively new to explicit dynamic simulations and I am currently running a drop test (a steel mass falling onto a steel container) using Mecway with the OpenRadioss solver.

I need to evaluate the reaction forces at the supports to calculate the total impulse of the impact. However, as shown in the attached screenshot, the reaction forces seem massively exaggerated.
Mass of the cylinder 6800 kg - mass of the container 5000 kg - Free fall from 320 mm height

AI Gemini hint: "I suspect this is the typical "ringing" effect caused by elastic stress waves and the contact penalty algorithm. My question is: is this completely normal? Should I simply integrate this raw data (or apply a moving average/low-pass filter) during post-processing to get the correct impulse, or are there specific solver settings I should adjust to smooth out these contact forces directly?"

Thanks in advance for any advice!

MikeMcMullen

If anything it looks low to me unless the supporting structure and loads deformed a great deal. As far as damage looking at strains or deformations of the contact area compared to the fixed supports is more meaningful. One issue is the concept of "fixed is unrealistic. For meaningfull results the point of fixity should be such that is several to many times the the distance a sound wave takes to go the distance to the support.