Quasi Static Analysis Radioss

Endeavor

Hello,

 

I am performing quasi static analysis for a truss work. I would like to clarify my following doubts. Could anyone please help me in this regard.

 

1. I have chosen the following control cards. My analysis runs and I am getting the result. But I would like to know what kind of analysis (implicit/explicit/ nonlinear/linear/ quasi static/impact) has been carried out with these card images that I have chosen (because I have not chosen any specific cards for quasi static or implicit linear or implicit non linear etc.)?

 

2. I want to do specifically a quasi static analysis. I have added the bending load curve with load application from 0 and ramp it to 10000N with 300milliseconds time interval. When I try to add the ENG_IMPL_QSTAT card to perform quasi static analysis, it shows me 'segmentation violation' error. The same happens when i choose the ENG_IMPL_LINEAR card. I would like to know here the reason why I get the 'Segmentation Violation' error and how do I perform quasi static analysis?

 

3. When I use Failure model for materials like '/FAIL/JOHNSON', what will the analysis run for? Will it run until the failure of the material happens? What type of analysis will be chosen?

 

 

Thanks in advance.

 

gopal_rathore

Hi,

Please find the remarks below:

1) The analysis run is though explicit technique. As there are no specific cards for implicit run. You can also check the time step where in explicit schemes uses relatively very low time step than implicit schemes. Quasi static is type of physics which lies in between dynamic analysis and static analysis which refers to slow ramp up of loading forces. It is non-linear or linear depends on the type of material , contact definition etc. But as you mentioned you are working on truss problem where in most of the parameters will be in linear domain as we don want any non-linear behaviour in such designs

 

2) For a quasi-static analysis, you can also use Optistruct for solving as less non-linearity parameters are expected in your truss model

 

3) Yes it is for material failure. For a truss we can check failure with stress values itself and compare it with material yield values. As we do not want the stress to go beyond the yield and also have factor of safety of say 1.5-2

 

 

 

Endeavor

My doubts are clear. Thanks for your time and reply!

 

I would like one more detail regarding my first question. Suppose if I choose quasi static loading case with bending load as I mentioned with 300ms interval for every step, can I say that the engine runs an explicit quasi static analysis on my model?