External forces, such as process forces, can be applied as function of time or as function of any motion result, that is calculated by SAM. The same holds for external torques. The user can define a force (value & direction) as function of time. Forces/torques can also be modeled as a function of any kinematic property. This feature can be used to model a force that has a fixed value and an angle that corresponds with the angle of an element. This basically mimics a force in a local coordinate system that moves together with the motion of one of the linkages. Mass/inertia can be part of a beam or it may be attached to a node.