Sigma_max is the maximum stress over the entire area or volume depending on the integration domain. Here sigma can be considered the first principal stress but has alternative definitions depending on other criteria I won't detail here. I am currently using quadratic quad elements and require high precision. I previously used the average value from each element via an etable but the results were not satisfactory. Is there a command to perform integration of a user specified expression within Ansys Mechanical APDL? Here sigma_max and m are scalar values I can retrieve.

To determine the effective volume and surface area of test specimen in Weibull analsys with a nonuniform stress field, the previous equation must be integrated over the area or volume where m is the Weibull modulus determined from experimental data.