Simplified model to consider influence of gravity on impacts on structures: Experimental and numerical validation

Abstract

Traditionally, the effect of gravitational force has not been considered in the study of impacts on structures, partly due to lack of knowledge. In most cases, it may be reasonable to disregard this effect, but it is not clear where the limit is and, therefore, in which cases its effect should be considered. Is this limit the same regardless of the type of structure? What criterion should be adopted? This paper develops a simplified model that allows, through a simple formulation, the calculation of the displacement and contact force in an impact considering the effect of the force of gravity on the structural response. In this article, the formulation has been validated with experimental impact tests on beams and also with finite element models. In addition, a coefficient is proposed which enables the evaluation, prior to any analysis, of whether the impact will be significantly influenced by the force of gravity, whatever the structure under study.