Linear Transient Stress Analysis

[JohnyGluebag]

Good day,
I am looking for books, references, tutorials to learn how to do a linear transient stress analysis using Femap/MSC Nastran. More specifically, Direct Transient analysis.

I am comfortable with static stress anlysis and modeling. What I am finding difficult is getting information regarding the functions used to describe the loading and the time intervals used for the analysis.

Over time I want to linearly ramp up the load on the structure, then ramp down the load. Then let the analysis run for a bit to monitor the stress and deflections after the loading is finished. The loading is taking place over a about 0.03 seconds, an impact load basically. I have done a few runs and have found that depending on how the loading function is defined, results can vary.

Anyway, I appreciate any comments and advice.

JohnyGluebag.

 

[ThomasH]

JohnyGluebag:

If you look at the MSC site under support/example exercises (link below) I think you should find something useful.

http://www.mscsoftware.com/support/online_ex/Library.cfm

Good Luck

Thomas

 

[JohnyGluebag]

Thanks ThomasH.
I am finding that there is no single resource to figure this out. I guess it would all be to easy then eh.

JohnyGluebag.

 

[EricZhao]

Transient load should be obtained from field testing/measurement. If you don't have real world data for your shock load, I would suggest you to consult some vibration testing standard, such as MIL-STD 810F (Method 520.2). You can use the shock load function descripted in that testing standard. By this way, you know your design would at least conform to that standard.

 

[JohnyGluebag]

The pieces are starting to come together. A consultant is supplying the physical testing data with load curves, numerical testing to compare too and such.

After running a couple transient cases it is interesting to see how the model buckles differently than shown in the eigenvalue analysis...so many things to figure out....

While I am totaly stressed out and concerned about my lack of experience (obviously doing good work is important), I am finding this very interesting and hope to come out of this with a good experience. How and why this job has been bestowed upon me is a messed up tale that I will not bore people with here.

Thanks again for the replys,
JohnyGluebag.