More displacement with lineal analysis than geometric no lineal

Sergio

Hi, I'm modeling a simple steel sheet part that is hanging by his ends, affected only by gravity load. In the real life this part is deflecting too much (about 10-20mm for about 2000 overall length, will measure later), so I need to increase some bends angles to make it stiffer.

Now the problem, I have modeled the part with three hexa elements in thickness, and using second order elements. With a lineal analisys I have 22mm of deformation, but with geometric no lineal I have about 7mm... is normal to have this stiffer results? I would say that no lineal results would be higher than simple lineal

Victor

If the ends are fixed in the horizontal direction, then yes, nonlinear should have less deflection because the sheet would be stiffened by its tension, similar to a catenary.

If one end is free to slide horizontally, then I'm not so sure but I would think linear should have greater deflection because gravity only acts normal to the sheet, tending to bend it. Whereas for nonlinear, after it starts bending, a component of the gravity force will be in the plane of the sheet and not contribute to bending.

Since it's a simple solid model, perhaps compare to the internal solver too.

Sergio

Thanks for the support. I have removed the horizontal constrain to be more like the real situation, after that both models shows about the same deflection (20mm). For the lineal model, internal solver gives the same result, didn't try yet with the no lineal.

By the way, is there some issue for uploading files? I'm trying to upload some pictures from this morning without success.

Best regards.

Victor

Some file types are not allowed so you can zip or rename them. Or sometimes the forum is just flaky and refreshing the page might help.