Thank you so much for answering, nclarification: I performed a thermal analysis on the wall in which the front elevation of the wall is under fire. things went smoothly, and now i'm trying to solve the structural model. the temperatures from the thermal analysis are assigned on the nodes of the front elevation. nhere is my wall, fixed from the bottom with UZ and UY constrained. I took half of the wall in length so I constrained Ux on the side. eccentric axial load is applied on a line of nodes on top of the wall. nAs I said, I made volumes on top and bottom of the wall to reduce stress concentration. the volumes have a steel material with assigned Ex and PRXY. I tried to make the upper volume bigger in thickness but the result didn't change. nI also tried to make the upper volume exactly as experimental. nI also made a trial where I divided my wall in height into three volumes in order to assign only elastic properties of concrete for these volumes. (no stress-strain diagrams at elevated temperatures). the solution also diverged. nnI increased the number of substeps from 50 to 500 but no change. nsometimes the error just says that solution is not converged and sometimes it shows the error I inserted in the post. nThank you again and Best Regards,nMaha n