Software for Time History Analysis of Shell Structures

[JoeH78]

DEar All,

I'd like to know which s/ware can perform time history analysis for structure comprised from thick-shell elements. Recently I noticed that sap2000 was not capable of doing that and I'm afraid that Etabs also will not be able to do, so they work only for frame based elements. I also will appreciate if you specify which s/ware you use for that purpose.
REgards,

 

[ThomasH]

Hi

I don't know exactly what you need but I think that any general finite element software can solve it. Names like ABAQUS, Ansys or Nastran to mention a few.

Regards

Thomas

 

[JoshPlumSE]

I would offer up RISA, provided you were talking about linear time history. But, if you think that SAP2000 can't do this (I'm pretty sure it can), then you may have criteria that I'm not aware of.

 

[WARose]

I use STAAD for all my time history work. I'm not sure why type of "shell" we are talking about here but STAAD can (for example) model a dome with a fine mesh of plates. (STAAD does not (to my knowledge) have curved elements.)

 

[IDS]

I have recently been doing some non-linear time history analysis with Strand7, which has beam, shell and plate elements.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[JoeH78]

AFAIK all Abaqus, Ansys, Nastran are very high level acadamic purpose softwares, that means it will be very difficult to evaluate directly from outputted stress tensors and calculate the reinforcement for shell type element and check the regulationary limitations ultimate stress, deflections etc.. . So I'll need more practical s/ware, based on that it seems that STAAD, RISA and STRAND7 can do that.

To elaborate further, shell element will be Reissner-Mindlin thick shell element.

@JushPlum SAP2000 can do it but only for frame elements, not for shells.

 

[theonlynamenottaken]

I've done time history analyses for thin shell plate elements with GTStrudl, and I know they have some Mindlin based thick elements. I would imagine that it would be capable.

 

[ThomasH]

@ joehigashi
I would not say that ABAQUS, Ansys, Nastran are "academic". But they are definetly "all-purpose" and have options to handle things like element formulations. I work with structures and Nastran for dynamic applications.

As I understand it now, you want what I would call a "design" software. But first you just asked for a software .

Regards

Thomas

 

[JoshPlumSE]

Some comments on plate /sheel element validation between RISA, SAP, STAAD and GTStrudl that I worked on doing NQA testing for my previous company. As well as various comparisons and validations that I've done since I was at RISA. Though please understand that I'm not a PhD, but rather an SE trying to navigate these very esoteric concepts:

I know that RISA's is based on Mindlin-Reissner with interpolating functions for out of plane shear making it effective for thin or thick plate applications. Reference the MITC-4 element from KJ Bathe.

My impression is that SAP's plate/ shell element is also appropriate for thick plate applications. Though I don't have much information about the actual formulation, I believe it is based on an element formulation from Ed Wilson. The details should be reasonably easy to look up. However, I can say that it behaves very similarly to RISA's element in the tests that I have run.

GTStrudl has a number of different elements to choose from. Some will be good for thick and some will be good for thin. So, you have to know which ones to use and which ones to avoid.

STAAD's plate element formulation always seemed a little weird to me. It somehow puts some strain energy into the drilling degree of freedom, which I was originally taught shouldn't be possible. Then I read an excerpt from an FEM book by MacNeal (Finite Elements: Their Design and Performance) which criticized these types of plate elements. That being said, the test results matched up with RISA's fairly well (though not as well as SAP's if I remember correctly). Therefore, I can't say anything all that negative about it in practice. It's just that I'm uncomfortable with it in concept....