Springs

A spring is an elastic element used to store mechanical energy which retains its original shape after a force is removed. Springs are typically defined in a stress free or "unloaded" state. This means that no loading conditions exist unless preloading is specified, which creates an initial "loaded" state. Springs connect two bodies together, which connects them and transfers the load from one body to the other. Longitudinal or torsional springs generate a force that depends on displacement or rotation, respectively.