Abstract:The critical stress and the exponential parameter of the buckling inertia term are treated as the twin characteristic parameters for the plastic dynamic buckling of rectangular thin plates subject to in-plane step load.The governing equations are derived by the adjacent-equilibrium criterion.The supplementary restraint condition of buckling deformation at the fronts of compression waves is obtained in terms of the criterion of transformation and conservation of energy in the transient process of dynamic buckling.The necessary and sufficient conditions of determining quantitatively the two characteristic parameters and buckling modes consist of stability equations,boundary conditions,continuity conditions at the front of plastic wave,and the supplementary restraint condition.In the dynamic buckling process of the rectangular thin plate, the relations of its thickness-width rate, the amplitude of impulsive loads, buckling modes and critical buckling length are studied.