I am having some trouble in doing the motion analysis assuming a spring in an assembly. My structure is a bumping post used at the end of the tracks of a train to avoid trains getting offtrack. So I have to calculate the change in stress in the whole structure with the introduction of a spring at point of force(i.e. the pads). I am attaching the model itself so it could provide a better idea. Please help me as my whole Master's Project depends on this.