Apparent structural stiffness of closed mechanisms under the effect of internal forces during dynamic motion

When a mechanism is overconstrained it leads to the generation of internal forces. These forces do no work but have an effect on the apparent structural stiffness of the mechanisms. The degree of this effect depends on the magnitude or the mode of the internal forces and the geometry of the mechanisms. Internal forces may result from external or gravitational forces or the inertial loads during motion. If a mechanism has a closed chain structure, the redundant actuation may generate internal forces as well. -. . `o The authors analyse the apparent structural stiffness of the closed mechanisms due to redundant actuation and the forces arising during dynamic motion