Optimisation of a beam in bending subjected to severe inertia impact loading

This paper summarises an optimal analytical study of a bar when it is subjected to shock inertia loading such that the severe bending causes permanent yielding. The findings are related to a practical case study application and help explain the necessary actions that have to be taken to minimise the impact damage. The analysis relates the sudden strain energy which the bar gains following an impact (when either the stationary bar is collected by a body moving with substantial momentum or alternatively when the moving bar is suddenly brought to a halt) and establishes the bending strength as a function of mass, stiffness and other kinematic conditions. The optimal analysis results in a surprising paradox which is borne out in the actual detail design solution to a critical component which had caused major maintenance problems in the braking system of a railed vehicle. The study reveals some interesting findings relating to the best bar configuration in terms of geometrical design, support locations and material choice.