Blast Wave Structure Interaction Studies on Shaped Concrete Structural Units and the Influence of Charge Geometry

Abstract

Blast loading studies assume significance on account of the destructive effects newlineon structures and the possibility of endangering human life. In the present circumstances newlineit becomes all the more imperative. This research study investigates the blast wavestructure newlineinteractions in shaped structural units and also examines the influence of newlineexplosive charge shapes in the spatial distribution of blast pressures on the incident newlinefaces of the structural units. Three distinct structural shapes, namely square, cylindrical newlineand apsidal are considered in the study. newlineThe finite element analysis is carried out using the nonlinear finite element code newlineLS-DYNA. Study uses theoretical and numerical methods for the validation of the newlineresults obtained. newlineThe 3 D surface plots of the spatial distribution of incident blast pressures reveal newlineclear patterns of the variation in the incident pressures on the front and side faces of the newlinestructural units. The mean values of the incident pressures for the square unit indicate newlinean increase in the range of 1.4 % to 6.5 % over the corresponding values for the newlinecylindrical and apsidal units. The perceptible variations in the average and maximum newlinevalues of the blast parameter indicates clearly the attenuating and dissipating effects of newlinethe curved surfaces. newlineDiffering aspect ratios of a cylindrical charge generates distinct patterns of the newlinespatial distribution of effective pressures. A 54 % reduction in the effective pressure is newlineobserved when the aspect ratio of the cylindrical charge varies from 1 to 2. In newlinesimulations involving both the spherical and cylindrical charges, random forests newlinealgorithm was used to analyze the response values and build predictive models. The newlinedifferent charge shapes generate unique patterns in the spatial distribution of the newlineeffective pressures. In the simulations analyzing the displacement response, it is found that peak displacements of the apsidal unit are lower by 69 % than the corresponding values for the square unit. Factoring the two constitutive models, namely RHT and CSCM.