Theoretical and Experimental Studies on Mechanical Impact Dynamics in Multibody Systems

The dynamics of mechanical impact is studied for a planar kinematic chain consisting of a freely moving bar and a fixed plate. Through mathematical modelling and virtual prototyping, the dynamic components of the impact function are identified. The structure of the impact function thus determined is used to study the dynamic response of an articulated quadrilateral mechanism. This mechanism is part of the structure of an experimental stand used for fatigue testing of a torsion spring-bar. It was considered that due to errors in execution and assembly or due to wear, radial clearance occurs in the rotational joint between the rod pivot and the rocker arm bearing. This clearance will lead to the generation of a mechanical impact with considerable effects for fast moving mechanisms, thus the effect of the impact force on the kinematic and dynamic parameters of the mechanism will be studied. The evolution of the kinematic and dynamic parameters before and after the impact is studied under the assumption that the contacting bodies are deformable.