Manipulating ABD formulation 1

[Siavash Shoja]

I am working on a transient simulation of a laminate. I use the composite layups feature to use laminate theory for characteristics of my shell elements. Here you should define the properties of a ply so that Abaqus uses laminate theory to create the ABD matrices. My question is, Is there anyway I can get access to the matrices and manipulate them? Or define the ABD matrices instead of defining the ply properties?
My aim is to decrease the D (the bending stiffness matrix) for bunch of elements in my structure.

/Siavash

 

[Mustaine3]

It is possible to look at the ABD matrix for selected elements or the whole structure, but I think it is not possible to modify it directly.

 

[Siavash Shoja]

Thank you for the reply. Can you tell me how I can look at them please?

 

[Mustaine3]

There are multiple ways:

1. Use the A/CAE Plugin. Search in the DS Knowledge Base for answer QA00000008126 to find the plugin and instructions.

2. Use a Shell General Section (integration before analysis) and request model data output when creating the job. Then it is written into .dat during the datacheck.

3. Use *Element Matrix Output. Optionally add *File Format to get ASCII data.

 

[Siavash Shoja]

Well I think I found the answer. You can define your ABD matrix by defining the laminate properties in General Stifness Section. There you have a 6 by 6 matrix which is your ABD matrix (Section 29.6.6).

 

[Chris10B]

I am also attempting to reduce the bending stiffness for the purpose of simulating a prepreg molding process. I am avoiding having to write a material subroutine. Siavash, were you able to successfully use the SHELL GENERAL SECTION keyword to define your material?
Thanks,

Chris

 

[Siavash Shoja]

well I have not tried it yet myself. But seems if you want to change the bending stiffness you should change the D[4,4],D[4,5],D[4,6],D[5,5],D[5,6] and D[6,6] of the stiffness matrix