پیش بینی رفتار پیش و پسا-گسیختگی ورق‌های دایره‌ای تحت بارهای دفعی با استفاده از تحلیل‌های حدی تغییر شکل (علمی-پژوهشی)

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, it is assumed that 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 is 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 considered. Since, value of residual velocity after tearing can perform principle role for validation of a quasi static estimation of the deformation at transit threshold from the first failure mod into second one. So, having amounts of relevant energies, value of this velocity is evaluated without needing to dynamic analysis. Finally, by comparisons between obtained results from introduced models and other works and experimental data, good agreements of them are observed.