The force displacement graph of the abaqus input file and my force vs displacement graph are different. I found that abaqus model has only one instance and my model has two parts top and bottom so two instances. I want to know if this is the cause of the problem I would also want to know how do I solve this issue

Abaqus ​​​​​​​Technical Domain usage ​​​​​​​Force Displacement graph ​​​​​​​Edu ​​​​​​​