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Composite delamination simulation

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Hello all,

I would like to ask if RADIOSS (any block or RADIOSS bulk) supports the VCCT (virtual crack closure technique) and/or CZM (cohesive zone modeling) interface elements used for onset and simulation of delamination propagation in composite structures. If yes, what kind of material law and element properties will be used (in hypermesh)? Is it possible to calculate the energy release rates (GI,GII,GIII) and plot them in Hyperview?

To assist any attempts for an answer, suppose we have two surfaces with shell elements representing two layups of the same composite structure (PCOMP or PCOMPG properties assigned) and we want to create the interface between them to represent the glue material (matrix). Any suggestions about the elements that will be used in the interface are welcome: solids, CELAS (springs) etc.

Thank you in advance for your assistance.

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You can do it by using brick elements defined with material law 59. Put them in between your layers of shells which represent the plies to model the adhesive.


Take a look here:


http://www.altairhyperworks.com/hwhelp/Altair/hw12.0/help/hwsolvers/mat_law59_connect.htm


It says that the bricks can also have 0 height but i do not get that. If anyone knows how to do it please post it here.


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Ευχαριστώ  :)


 


Sorry, I haven't checked on this topic for a loooong time. Anyway. thank you for the link provided, although I cannot see it because it requires customer login which is something that I currently do not have (we used to have a license with support, but right now we don't). As to your question on the creation of zero-thickness (0 height) 3D elements here is the "trick" that I've done and tested:


 


-First, create three components called "2D mesh", "upper" and "lower".


- Make your 2D mesh component current and create a 2D mesh on a surface (using 2D-->automesh).


- Now, make current your "upper" component and go to tools-->translate-->select elements and select all your elements in 2D mesh component. One you've done that, click on "elements" button and select "duplicate". In the new window that appears select "current comp" and your duplicate elements will be transferred to the "upper" component. Click "return" since we do not actually need to "translate" any elements, this was only used in order to create a duplicate.


- Make current your "lower" component and repeat the above step. This time select elements by component and select "2D mesh" to select the initial mesh. At the end you will have two components with the 2D elements created overlapping each other. You can verify their existence by simply turning on/off the elements icon next to the component names on the assembly tree.


- Once you've done that, simply go to  3D-->solid map-->select general and select "none" as source and destination geometries. Select source elements by component and select "upper". Do the same for destination elements but now (surprise, surprise) select "lower". Have the show "solidmap mesh" option selected. Press return and voila! A solid map mesh will be created with 3D elements of zero thickness.


 


That's all.


 


PS: I have exported this mesh (as a NASTRAN .bdf) in other pre-processors (call me MSC...) and it is recognized like a charm.


 


I hope this helps.


xrek likes this

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Hi guys

and how is the connection between the faces and the "connection elements" (MAT59) is achieved? arent we suppose to enforce a contact between them? and the this material law is combined with lad_dama failure?

 

Thx

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