An Experimental Investigation of the Dynamic Response of an Elastic Mechanism

Abstract

Interest in the dynamic response of elastic mechanisms has recently prompted several analytical investigations. To date however, experimental data on the response of such mechanisms has been lacking. In this paper the experimentally determined steady state elastic response of a planar four bar, quick return mechanism is presented. Strain data are given for points on the coupler and output links for several different input rotation speeds. Structural damping of the links was also determined experimentally. Excitation of the link bending modes by the quick return impulse is clearly evident in the recorded strain data. The experimentally determined bending strains are compared with analytical results obtained using a digital computer program which employs a matrix structural analysis representation of the mechanism at a discrete set of crank angle positions. Agreement between calculated and measured strain data is good.