Prediction of Pre and post- Failure Behaviors of Circular Plates Subjected to Impulsive Loads Using Limit Analyses of Deformation

Two effective quasi – static models are presented to consider pre and post- failure behaviors of the clamped circular plates subjected impulsive loads based on upper bound limit analyses of deformation. In first model, final profile is considered to have a conical shape, which is represented by radial and vertical motions of a single peripheral plastic hinge; permanent deflection is calculated before local failure. In second model, supposing the final deformation being as a dome shape, mechanism of deformation is caused by multi- peripheral stationary hinges with uniform or non- uniform distribution. In this part, motion after severance of the plate is considered at the instance that the local failure is occurred. Calculating plastic deformation energies, permanent deflection before the severance is computed and influence of number and distribution of hinges are investigated. Since, value of residual velocity after tearing can perform principal role for validation of a quasi static estimation of the deformation at transit threshold from the first failure mode into second one. So, having amounts of relevant energies, value of this velocity is evaluated without needing dynamic analysis. Finally, by comparisons between obtained results from introduced models and other works and experimental data, good agreements are observed.