Dynamic Analysis of Plates Subjected to Explosive Loading: Comparison Between SDOF and FEM Models

Resumo

With the global increase in explosive events, arising from armed conflicts and/or accidental occurrences, a thorough analysis of the dynamic behavior of structures under this type of load becomes important. The explosive phenomenon causes an overpressure (positive) wave with a subsequent underpressure (negative) phase, which is often disregarded. Moreover, recent studies have highlighted that this negative phase can generate displacements and stresses as relevant as the ones from the positive phase only. This work investigates simply supported plates subjected to explosive loading considering the membrane effect (laterally immovable condition) which introduces nonlinearities in the model. Due to the problems mathematical complexity, these nonlinear dynamic analyses are usually performed using complicated finite element models. In this way, a software called DYNAblast was developed using a simpler approach based on a Single Degree of Freedom (SDOF) analytical model which incorporates the von Karman plate theory. Dynamic analyses were carried out in DYNAblast to understand the influence of the positive and negative phases of the blast loads, as well as the contribution of the membrane energy of the plate. Numerical models implemented in ABAQUS software were used for the validation of DYNAblast results, with excellent agreement.