FEA Validation of Matrix Displacement Mehtod

[conorandrew]

Hi all,

First of all thank you for taking the time to read this, it is much appreciated and any help you could give would be great.

I am attempting to use ABAQUS to validate the Matrix Displacement method of thin walled structures. Essentially I am attempting this in 3 stages:

1. A 2-D truss structure
2. A 3-D truss surrounding one shear panel
3. Larger Truss/panel assembly such as a box structure

Analytically the assembly (2) consists of one rectangular constant shear flow panel bounded by 3 rod elements, with one edge embedded in a "wall".

I have choose to model on FEA as follows:

Panel - 3-D Deformable Shell with Homogeneous Shell Section
Rod - 3-D Deformable Wire with Truss Section

I use a TIE constraints to join the elements to the panel

Essentially my displacement and panel shear stress results are o.k, however calculation of nodal reaction and element stresses are WAY off. And when I move to stage 3, most of the displacements are also WAY off (in this stage I model similarly and introduce several panels in different planes, again with a TIE constraint).

Has anyone attempted this kind of model before? or no of any issues they have had?

Again, thank you in advacne for any help

Conor

 

[DanStro]

You should probably move this post to the Abaqus forum.

Han primo incensus