Thanks for your reply. I performed analysis by turning on inertial relief for static structural analysis. Now, consider that I have to perform topology optimisation where mass of the body will increase/decrease after each topology optimisation iteration. This will change the inertial load (acceleration) significantly and the model will be imbalance. So for topology optimisation and even for axisymmetric model analysis, I can't turn on inertial relief. Thus, I need to update the acceleration for each iteration and this is where I am struggling to figure out the way that can take care of variable acceleration. I looked for APDL command, parameter set using Excel and other tutorials but no luck, n