quasi-static

[amar]

Hello Dr.Bergstrom,
I did one of my riveting analysis with explicit and compared the stresses of interest to my standard analysis. The xeplicit analysis I did with different loading rates 0.001, 0.01,0.1 time to ensure everything. But the explicit analysis and standard show around 37% difference in the stresses. As far as I know I have done everything to make sure that I am not doing something wrong in my explicit analysis ( like applying displacement as smooth step etc.) Though my energy plots satisfy the requirements for the explicit analysis since my stresses dont match up does this mean that my assumption of this being a quasi static analysis is wrong? does this mean I am trying to simulate the analysis as quasi static with explicit when its is not ?
sincerely
amar

[Jorgen]

Hello Amar,

That is a large difference in the stresses. If performed correctly, implicit and explicit simulations should give the same results. Did you use mass scaling in your explicit simulations?

Jorgen

[amar]

Hello Dr.Bergstrom,
No I didnt use mass scaling in the analysis since I thought that might introduce one more parameter which might cause an error. So I solved the xplicit analysis with the original material density. I have made sure that my analysis is right. I am applying displacement using smooth step amplitude as recomendded. But since the results are not matching I was wondering about whether its a quasi static analysis.
amar

[Jorgen]

It is somewhat suprising that you do not get better agreement between the Standard and the Explicit simulations. As you mention, the likely explanation for this is that it is not a quasi-static problem, that is, inertial effects might play a role in the deformation response. To check this you can try to run an implicit dynamic simulation.