K. Senthil

Ballistic resistance of mild steel plates of various thicknesses against 7.62 AP projectiles

The ballistic resistance of mild steel plates has been studied against 7.62 AP projectiles through numerical simulations using ABAQUS/Explicit commercial finite element package. The projectiles were impacted on 4.7, 6, 10, 12, 16, 20 and 25 mm thick target plates at varying incidence angles. The material parameters proposed by authors for the Johnson–Cook model were used to predict the material behavior of target, while the material behavior of projectile was incorporated from the available literature. The numerical results thus obtained have been compared with the experiments available in the literature. The experimental and numerical results with respect to failure mechanism, residual projectile velocity, and maximum angle for perforation and the effect of configurations on spacing and critical angle of ricochet have been compared. A close correlation between the experimental findings and the predicted results has been found. In general, the resistance of target has been found to increase with an increase in target obliquity. The critical angle of the projectile ricochet has been found to decrease with an increase in target thickness. The ballistic limit for all given thicknesses of mild steel targets has also been obtained numerically. The ballistic limit thus obtained has been used to calibrate the Recht–Ipson empirical model for calculating the residual projectile velocity corresponding to a given incidence velocity. Simulations were also done for three-layered target of 4.7- and 6-mm-thick plate and spacing was varied to study its effect on their ballistic resistance. The variation of spacing at normal impact was found to have an influence as long as the spacing was smaller than the projectile length.

Behavior of cantilever and counterfort retaining walls subjected to lateral earth pressure

Abstract Three-dimensional (3D) finite element simulations have been performed in order to study the response of cantilever and counterfort retaining walls subjected to lateral earth pressure using ABAQUS/Standard. Four retaining walls with different geometrical configurations were analyzed including three cantilever and one counterfort wall. The results thus obtained were compared, and the mechanics involved in the behavior of the retaining wall was discussed. The lateral displacement, vertical settlement, and stresses developed in each component of the retaining wall were studied and compared with the other walls. The choice of the retaining wall based on the economic analysis was also discussed and compared.