How to do a Prestressed modal analysis with optistruct?

Altair Forum User

Hello everyone,

I want to do a prestress modal analysis? However, I don't know how to set up the case. Is there any example? Thank you

 

Best Wishes

Roy

Altair Forum User

Hi @Roy Duan

Yes, you can perform PreTension Modal analysis through HM-OptiStruct using STATSUB (PRELOAD) case control command.

 

You need to create two load steps, the first step can be Linear Static analysis

 

In the second load step which is Normal modes, pick the previous Linear Static analysis under STATSUB(PRELOAD) as shown below:

 

SUBCASE 1
    ANALYSIS = STATICS

SUBCASE 2
    ANALYSIS = MODES
    STATSUB(PRELOAD) = 1
    SPC = 2
    METHOD = 3