I just have a remark... If your goal is to try to get a more accurate result, this is not the best way.
Compare to ANSYS, wich is a h-method solver, you must increase the number of node to get more accurate result. But, Mechanica is a p-method, so you must set an higher polynomial order to get a more accurate result.
For a h-method solver, the equation between the node is linear or quadratic. But for a p=method, the equation is a polynomial.