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Energy balance in a quasi-static explicit analysis

Energy balance in a quasi-static explicit analysis

Energy balance in a quasi-static explicit analysis

(OP)
Hi all,

I would like to ask some advice on interpreting whether or not my quasi-static solution is acceptable. In the manual it says: "As a general rule the kinetic energy of the deforming material should not exceed a small fraction (typically 5% to 10%) of its internal energy throughout most of the process"

I have a model involving two parts which undergo large deformation and come in contact. At the end of the simulation I plot kinetic vs. internal energy for the model as a whole and for the individual parts. I can see that for the model as a whole and for one of the parts, kinetic energy is well below 5% internal energy throughout the analysis. However, for one of the parts in the analysis the kinetic energy exceeds 5% internal energy for a very short period of the (~2.5% of total time) and then quickly becomes negligible. If I animate the results of my model I can see this part undergoing a small oscillation as a result.

I was wondering how should these results be treated? Should I modify my analysis to reduce the kinetic energy in the problematic part? Or, as the period for which the kinetic energy exceeds 5% internal energy for the part in question is small compared to the overall solution time, are these results acceptable? Just curious to get other peoples opinions.

Thanks in advance,
Dave

RE: Energy balance in a quasi-static explicit analysis

Pretty sure you're in the clear. The key part of the quote you gave is "throughout most of the process." Throughout most (97.5%) of the process you are below 5% and it's fine at steady state, so I think it's valid.

RE: Energy balance in a quasi-static explicit analysis

(OP)
Hi,

Thanks for the response. I guessed the results were probably valid considering the period of high kinetic energy is so short. Just needed a bit of reassurance!

Thanks again,
Dave

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