Abnormal deformation of link180 element
l m running a static analysis on a simply-supported prestress beam in APDL. l used solid65 to model concrete, beam188 to model reinforcing steels and link180 to model the prestressing strands. prestress was applied by defining thermal expansion for the prestessing strand material. l defined 3 different load steps. load 1 ( the prestressing), load step 2 for self-weight and load step 3 for applied external force. l got convergence problem after a very small part of the external force was applied. l realize that the link element has an abnormal large deformation at mid span (see attached files). l have no idea of what could be inducing this problem. can you help me resolve this?