I am modeling a Brick masonry wall in Mechanical APDL R19.2 version. In this model, the brick elements (SOLID65) are connected to other bricks by a combination of Spring Elements COMBIN39 (representing Mortar) & contact elements CONTA178 (representing brick-mortar interface & its normal and sticking stiffness are a function of contact area of brick and mortar). Vertical precompression is applied as a first load step after which Lateral in-plane load is applied to the wall.
The problems I'm facing are:
1. Non-convergence of model; the wall fails abruptly after a few milimeters of lateral deflection
2. Brick elements behaviour (like E value) does not correspond to the Input value (Figure attached)
Can anybody please help me & guide towards the root cause of the problem?