Dynamic transient analysis (shock)

[AXS]

Hello

I am a french student, and i work on the dynamic response of an elastomer.
A shock is applied on my structure, and i would like to know the response.
I made some first works, with very simple linear models (Kelvin-Voigt)
and then, i had include (using Msc Nastran) non-linearities ( in transient , i create a amplitude dependant stiffness (K(A)) as an hyperelastic model.
In parralel, i created a frequency dependent model in frequency analysis.
but, cause of it is an dynamic excitation (shock : half sine, amplitude 260g during 6.25 ms) this analysis do not realy interest me.
I would like to know if someone may help my in my study, may i use a hyperélastic model or a viscoélastic model or both???

The different model i found, are aplied in frequency analysis
but i work on transient analysis

non linearities are frequency dependent
i want to work with velocity dependent stiffness, is it possible??

i can use MSC NASTran , IDEAS or Msc Marc for this work.


sorry for my poor engish!!!


best regard

Pierre Perrot
pperrot@estia.fr

[Jorgen]

The most appropriate model will depend on what you are trying to accomplish. Based on your description it sounds like you need a viscoelastic model. The most common viscoelasticity model is linear viscoelasticity, which is based on a hyperelastic model and a viscoelastic part that can be defined in terms of a Prony series. This type of model will allow you to study transient cases.

The main limitation of linear viscoelasticity is that it is only accurate at small strains.

- Jorgen