Finite viscoplastic deflections of an impulsively loaded plate by the mode approximation technique

The application of the mode approximation technique to a fully clamped circular plate is here described. Mode solutions for finite deflections are obtained from a sequence of instantaneous modes. Master solutions for chosen initial velocity amplitudes are constructed in nondimensional form. These depend weakly on a parameter of viscoplastic material behavior and size of structure, and so can be applied to a variety of loadings and structures. Finding each instantaneous mode shape and acceleration constitutes an eigenproblem, solved by finite elements with iterations. Comparisons with recent tests on steel and titanium plates are discussed in some detail.