distorted element during free-shape optimization

Rahul_P1

Hey everyone,

I´ve got a problem while executing a free-shape optimization with optistruct. As shown in the image below, there are few grids in my model, which do not move during the optimization iterations. Whereas their neighbor grids do correctly. This causes the following error: element XY distorted due to zero or negative jacobian...

Does anyone have an idea what the problem is? -The grid is not fixed using the GRIDCON-card...

Thanks, TKone

Rahul_P1

Do a element quality check and refine or remesh to improve the element quality, however , You may need to rethink how you define the free shape design region,

Ideally, free-shape design regions should be selected where it can be assumed that the shape of the structure is most sensitive to the concerned responses. For example, it would be appropriate to select grids in a high stress region when the objective is to reduce stress

Also control the the way in which the free-shape design region deforms, especially the direction type and the move factor so that it is more conducive,

read User's Guide > OptiStruct > Design Optimization > Free-shape Optimization > Defining Free-shape Design Regions