Learning Forum

[kwak dongkyu]

hi 

i have some errors to solve. 

my simulation situation is like above. in the hammer there is a box(from pic2) that move 1m/s to hit the box wall.

Box and hammer is separted. it's explicity dynamics. and all the material is alluminum alloy.

and my fixed support is on the handle part which is colored blue in the above image.

error1:

error2 :

error3:

 

Thank you

[SaiD]

Hi,

All the messages you shared above are warnings, not errors. So you should still be able to run the simulation. Are you unable to get the simulation to solve? If yes, then there may be some other errors present.

The second message states that the generated mesh may have some elements whose quality is not as good as you may have requested. You may have to use some local sizing or local mesh methods to improve the quality of the mesh.

The third message states that you have a few elements that are very small in size. Since LS-DYNA is an explicit solver, the smallest element in the mesh determines the time step. So in this case, you would get a very small time step and hence your simulation will be slow. One way to improve this is to use the CFL Time step tool (under LSDYNA Pre Toolbar) and figure out the regions where these small elements lie. You can then try to improve the mesh in this region to gte a more uniform mesh and get rid of these small elements. The other option you can try is using Mass Scaling.

Hope this helps.

 

[kwak dongkyu]

thanks