Large Truss - Extremely large stresses and deflections 1

[DarrenDM]

Hi there,

I'm trying to model a large truss (~180m span) with pin supports and cantilever ends however I am getting huge stresses and deflections in my results output under Gravity loading.

All units have been checked and are appropriate (m, N, kg, s, Pa, J, kg/m3)

In this model, I have imported the whole truss from AutoCAD as a single part, although I am also able to sub in parts separately using the Layer feature in AutoCAD. The problem I have with importing separate layers is that the deformed shape seems to "fall apart" (massive deflections, too large to even display shape). I assume this is some sort of problem with the interaction at the nodes for a multi-part model. Please tell me if importing the whole part as a single part is wrong.

I have attached the .cae file if any of you can give it a quick look over. This is a simplified model of the supertruss at the NRG/Reliant Stadium in Texas.

http://files.engineering.com/getfil...d-950f1cfced4d&file=Truss_with_Cantilever.cae

 

[Mustaine3]

Check your Youngs Modulus again.

 

[DarrenDM]

Thank you Mustaine3 for your continued help with my Abaqus queries, you have been of considerable help in my previous thread posts.

I have corrected the Youngs Modulus to 2e12 (200 GPa in Pa) - can't believe I made this error continuously! I seem to now have realistic output results, much appreciated!