Simplified model for analyzing soft impacts on structures: validation on steel beams

Abstract

Traditionally, simplified methods have been used to try to solve and understand impacts. These simplified methods sometimes assume hypotheses that excessively limit their applicability or are not sufficiently simplified and require numerical solutions. To analyze the influence of projectile flexibility in the structural response to impacts, finite element (FE) models are commonly used due to the limitations of simplified methods. This article proposes a new simplified model that enables the calculation of both structural displacement and contact force during an impact on simple structures, which can be represented as a spring-mass system, such as beams. The model takes into account projectile deformation and the effect of gravitational force on the structural response, providing an analytical solution. The proposed formulation has been validated by means of experimental impact tests and with finite-element models of impacts on beams. The effect of gravity, multiple impacts, and the influence of projectile flexibility when defining soft or hard impact are discussed in depth in this article. This research enables the calculation of complex impacts in an easy way while also facilitating the understanding of the phenomenon and the key parameters for managing it.