Superimposing preload stress field on all linear transient result increments

AmirMar

Dear All,

I hope you can assist me with this question.

I have a linear transient analysis with a nonlinear preload. The nonlinear preload induces stress field.

However the solution of the linear transient case is relative to the beginning of the step. I would like to take each increment and add the nonlinear result. Is it possible to do that?

Thank you,

Amir

Adriano_Koga

Found this in the OptiStruct documentation. In HV you should be able to create a derived loadstep with superposition.

 

Results

All results that are supported for regular structural linear analyses are also available in the corresponding prestressed linear analyses.

It is important to note that, while the prestressed linear analysis includes the effects of preloading as a weakening or a stiffening of the structure, the results from the prestressed analysis do not include the preloading results. For example, the displacements from prestressed linear static analysis do not include the preloading displacements. In order to get the overall deflection/stresses of the structure, the displacements/stresses from the prestressed linear analyses have to be carefully superposed with the preloading displacements/stresses while post-processing. Particularly, while post-processing complex results from prestressed direct FRF, the correct approach would be to first obtain the complex results for a certain phase and then superpose the appropriate preloading result. Any other superposing approach would lead to incorrect results.

Prestressed Linear Analysis.pdf