Shell Local Material Axis Definition for Orthotropic Material

Most orthotropic material rely on the parameter AOPT to define the change/update the default material axes defined by LS-DYNA. The default axis for every shell element is based on the order of the node numbers if INN=0 which is then based on N1-N2 and the cross-product of N1-N2 and N1-N4. The default material axes may not necessarily coincide with the direction of the intended axes for a given material. To help reorient the default material axes, LS-DYNA provides the parameter AOPT to reorient and further rotate the reoriented axes by using the BETA parameter in *SECTION_SHELL and/or *ELEMENT_SHELL_BETA. The following table attempts to illustrate this. I have ignored AOPT = 3, as I am yet to find a better way to illustrate it in a easier way but I will update it when its done.

Click to Enlarge

  • Nitin Devkar says:

    Hello Sir,

    Thanks for this useful information. Looking forward to have more information with AOPT = 3, which is used to define fabric warp and weft direction but definig it is not very clearly explained in manuals. Need more clarity on beeta parameter present in *mat34 and also in *section_shell (when ICOMP=1)

    Thanks and regards,

Leave a Reply

Your email address will not be published. Required fields are marked *