Tearing always initiates at mid-point on longer side of rectangular plate.
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Blast duration, aspect ratio and impulse affects deformation mode in the plate.
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Crack path along boundary deviates into the plate before reaching corner.
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Mode III deformation insensitive to aspect ratio and impulse.
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Design maps generated by a zero-period loading approximation are conservative.
Abstract
The deformation and failure of fully-clamped rectangular plates subjected to zero-period, uniform-momentum impulsive loads are studied. Analytical predictions are given for the critical velocities corresponding to the transition between deformation modes. Three-dimensional (3D) numerical analyses were performed using the non-linear finite element (FE) code ABAQUS/Explicit® to predict the maximum central deflection and deformation mode of rectangular plates for different combinations of aspect ratios and impulses. Two competing mechanisms of bulk material failure, viz. by the nucleation, coalescence and growth of voids and by shear band localisation, are implemented in the FE model to simulate tensile tearing, resulting in progressive ductile fracture, at the support. The numerical results are validated against experimental data for square mild-steel and aluminium plates where they are found to be in good agreement. Deformation maps delineating the different deformation régimes for different combinations of blast impulse and aspect ratio are constructed for plates of equal mass. The effects of imposing a finite-period, as opposed to a zero-period, impulsive load upon the deformation mode and maximum deflection are also discussed.
