How to set up loadcases and loadsteps correctly?

Hi,

 

I'm a student of the university in Kaiserslautern, Germany. As a part of a student research project I have to setup a model for the structural optimization of a component in Hypermesh/Optistruct.

 

The component shall be optimized in two different ways:

1.) minimum weighted compliance + volume constraint

2.) minimum volume + static displacement constraints

 

Three different forces are applied to the component. Each of them with an individual point of application and a different direction: force one in the direction of the global x-axis, force two in the global y-axis and force three in the global z-axis. These forces can take effect individually or all at once. Each force leads to a distortion of the component.

 

If I create one individual loadcase/loadstep for every individual force (3 loadsteps and 3 loadcases in total) does Hypermesh assume that only one of these forces takes effect at the same time, or does the solver also consider the superposition of all three forces while trying to find a feasible desgin? I'm asking this question because in the weighted compliance panel aswell as in the static displacement constraint panel I have to choose loadcases these options take care of. Do I already consider a superposition of all three forces by activating all three loadcases (x,y and z) in these panels or do I have to create a fourth loadcase (card image: Load) in which all three forces are combined to one superpositioned loadcase if I want to take of care the situation where all forces take effect at the same time?

 

Thanks in advance!