Learning Forum

[Dan Woods]

Hi,

I'm having an issue where the global acceleration from ACEL seems to be causing rigid body motion in my bridge model.

I have set gravity to -9806.5 mm/s2 and have my densities and other material properties in matching units (~0.002 - 0.008 g/mm3, E in N/mm2). The model seems to solve correctly when I apply pressure loads on the bridge deck elements but the global gravity load seems to always cause it to fail.

Am I missing something about how ACEL works? I've used DK to apply my boundary conditions. I'm not sure how the solution can solve with applied loads but not for gravity since surely any issues with my boundary conditions would apply to both cases. 

Any advice appreciated thanks.

[Ashish Khemka]

Hi Dan,

If you perform a modal analysis then you will come to know if there are any unconstrained bodies.

 

Regards,

Ashish Khemka