Indentation depth in a laminate

[lavecchiasignora]

Hi all,

Does anyone know a procedure to calculate the indentation depth of a laminate if a rigid sphere is traveling with a certain energy on the laminate?

For example: A quadratic laminate made up of 12 layers [0/90]s and a steel ball is thrown at the laminate. How large will the indentation depth then be?

 

[SWComposites]

How to calculate it analytically - no. Probably can be done with a highly nonlinear FE using Abaques, LSDyna, etc. But it would require lots of effort, material properties that are hard to obtain, and correlation to test data anyway.

Get a laminate, drop a hemispherical tup on it, measure the dent with a dial indicator.

SW

 

[Compositepro]

How the laminate is supported would be a major factor. So you could come up with an empirical equation if you had sufficient test data. But a purely analytical approach would be close to impossible.

 

[Yagonyonok]

Impact On Composite Structures, by Serge Abrate talks about it some, and may have what you are looking for.

I would still have to agree with the previous responses that it may be easier to test it emperically, rather than try to gather all the needed material properties.



Use of product voids warranty.

 

[Hansmeister]

There was a lot of work done on impact testing in the 1970's and early 1980's.

Do a literature search in the "Journal of Composite Materials".

 

[bellx1]

Out of curiosity if this was to be approached analytically how would one even start? I'm know the epoxy impact strength would play a huge role in these equations but how would you take into account the strengthening fibers?

This is the first post I read this morning and now it's got me going on this thought experiment,

http://www.compositescentral.net

 

[cloa]

The fibres would probably have no effect- no time for the fibres if perpendicular to react to sudden impulse and small component to the cross-section so little effect on the stress waves. They are also relatively deep so stress waves have decreased a little bit by the time of interaction. Have to ignore unlikely occurance of fibres being parallel to the impact.