Kinetostatic modeling of an asymmetrical double stepped beam for displacement amplification

A kinetostatic model of an asymmetrical double stepped beam under axial loading is developed. The beam is composed of two thick segments and three thin segments where a thick segment is between two thin segments, and the longitudinal axis of the thick segment is not colinear with that of the thin segment. The kinetostatic model based on the beam constraint model (BCM) is capable of predicting accurate bending and near buckling behaviours of the beam. A virtual rigid link neighbouring the non-colinear segments is introduced in the BCM to broaden the applicability of the BCM. An analytical formula to represent the critical load of a symmetrical double stepped beam under axial loading is derived and the value calculated by the formula agrees with the limit load of the asymmetrical double stepped beam within the elastic range. The investigated beam has potential applications in displacement amplifiers and robotic grippers.