Thin circular metal plates subjected to localised impulsive loads

• Main Author: Radford, Anthony Michael
• Other Authors: Nurick, Gerald N
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2016
• Subjects: Mechanical Engineering
• Online Access: http://hdl.handle.net/11427/21703

This thesis presents a theoretical model to predict the response of thin circular metal plates subjected to localised impulsive loads. These predictions are compared to experimental data and a finite element model. The theoretical model is described by two models where the first model predicts the plate deformation and the second model, using the deformation from the first, predict the strains in the plate. The first model or theoretical displacement model presents a stepwise velocity field approach, in which it is assumed that the explosive burns as a set of discretised rings spreading from the centre of the plate to the outer radius of the explosive. For each ring a velocity field for the plate is developed, and after including strain rate effects, a corresponding displacement is calculated. The total final displacement is determined by summing each of the individual displacements. The predictions are compared with all experimental data and a satisfactory correlation is found for both the mid-point displacements and the final plate shape. The second model or theoretical strain model uses the final displaced shape calculated using the theoretical displacement model to determine the strain in the deformed plates, with results being compared to uniaxial tensile strain and mean cap diameters obtained from experimentation. The maximum strain at failure calculated using the theoretical strain model gave good correlation to the uniaxial tensile strain and its position correlated well with the mean cap diameter.