Effective rigid perfectly plastic models to predict deflection and residual velocity of post local failure motion of impulsively loaded circular plates

Abstract

Two deformation models are proposed for clamped circular plates undergoing pulse loadings. By these models, behaviors of plate are studied effectively for the situations before and after local failure. In the first model, it is assumed that impulsive load is uniformly distributed and final deformation is of a spherical dome shape. In order to analyze this model, it assumed that under the shock wave, the mechanism of deformation is represented by a multi-peripheral stationary hinge scheme. In the second model, the final shape is considered to have a conical shape represented by a single peripheral plastic moving hinge. In this part, an alternate deformation model is proposed and the final shape is induced by transverse and radial motion of the plastic hinge. For each model, the deformation and motion after severance of the plate (post local failure) will be analyzed. Calculated plastic energies dissipated in deformation process, energy absorbed in boundaries during failure, residual kinetic energy and velocity after local failure are evaluated and discussed. Computed results show good agreement between our approaches and experimental data; better than that obtained with other models. Key words: Impulsive load, shear local failure, plastic hinge, rigid perfectly plastic, residual kinetic energy.