I'm working with a cylindrical tube structure. The problem at hand involves large deformations and the plasticity algorithm used is a basic isotropic yield function (von Mises). For the sake of plasticity calculations, the coordinate system does not affect the deformation since it is orthrotropic but I am interested in viewing the element stresses in a radial coordinate system where 1, 2, 3 are r, theta, z, rather than the current Cartesian system.
How do I go about assigning the simulation to a global coordinate system?
Thanks!
Thanks for the interesting question. First, by radial coordinate system, I assume that you mean cylindrical coordinates. What *Material model are you using that you want to view the stresses in cylindrical coordinates? This will matter if this is possible. There is an AOPT option within the *Mat card which needs to be AOPT=4 to switch to cylindrical coordinates. You will then also need to define the coordinates for origin P in the next line (XP, YP, ZP) and a vector along the z axis (V1, V2, V3). You can find the center of gravity of your cylinder for use as the origin by Element Tool -> Measure -> Inertia -> Active Elements Only -> All -> Apply. Make sure you only have the cylinder active when you do this.
If it's not possible to do this within LS-Dyna, you can still convert your stress from cartesian to cylindrical coordinate system using some equations.
Let me know if you have these options.