Learning Forum

[michail.stockfelt]

Hello

I know that enabling Large Deformations allows the solver to rearrange the stiffness matrix somehow, leading to more precise results when the deformation is "large", whatever that means. I am guessing some proportion to element sizes.

But does it also redirect loads?

If I have a pressure load inside a wall, and the wall bulges out from flat, the pressure should go from acting straight out to acting normal to the arc that the wall now forms.

Does this occur? Or is that another setting? Or is it something ANSYS does every time automatically?

[Gary_S]

Hi Sir_Dudebro
Large Deflection = APDL command NLGEOM,ON

Here are the relevant help sections as far as Pressure loads and Load following:

NLGEOM (ansys.com)
In a large-deflection analysis, pressure loads behave differently than other load types. For more information, seeLoad Direction in a Large-Deflection Analysis.
8.3. Understanding Nonlinear Analyses (ansys.com)
Load Direction in a Large-Deflection Analysis
Consider what happens to loads when your structure experiences large deflections. In many instances, the loads applied to your system maintain constant direction no matter how the structure deflects. In other cases, forces change direction, "following" the elements as they undergo large rotations.
The program can model both situations, depending on the type of load applied.Accelerationsandconcentrated forcesmaintain their original orientation, regardless of the element orientation.Pressure loadsalways act normal to the deflected element surface, and can be used to model "following" forces.Figure8.7:Load Directions Before and After Deflectionillustrates constant-direction and following forces.

[michail.stockfelt]

Thank you!