What are you trying to use the command for? Give an example please.
Dear Prof. Taylor, thank you again for your attention.
first a short answer to your question, If a panel is prestressed, I'd like to check whether the stress in prestressing direction is negative, in other words, totally under compression.
In the attached files you can see 3 Figures for our applications.
In Figure 1, the 3D arch model consists of several substructures, which are coupled with tied contact. The "black" lines in the middle are prestress cables. Each "cable" consists of two brick elements, with a tiny initial gap for creating prestressing, and coupled with tied contact.
In Figure 2, if the substructures are not prestressed (with zero initial gap), the contour plot of 1st principle stress shows that tension exists. (top right, with PLOT RANG 0 1E5, thus red color only for tension)
In Figure 3, the substructures are prestressed, but the problem is that there is always some tension in the first principle direction, instead of completely compressed, and the direction is not known. The plot with "PLOT STRE 1" shows only the projected stress, which is also not useful in this case.
So the solution in my opinion is either to check the direction of all the 1st/2nd/3th principal stresses, or use some stress plot in local coordinate system maybe by using ESTRess just for testing.
Actually, I am able to prove that the stress in cable direction is negative, but it is just to time consuming to check all the stresses with different plots. If you have any idea or are interested in that, please let me know.
Best regards,
sicheng6699
