NONLINEAR DYNAMIC BUCKLING OF DISCRETE STRUCTURAL SYSTEMS UNDER IMPACT LOADING

Nonlinear dynamic buckling of discrete dissipative or nondissipative, nonlinearly elastic, structural systems, geometrically perfect or imperfect, under impact loading is thoroughly examined. Applying the law of impulse momentum one can determine analytically the initial conditions valid immediately after impact. Thereafter, the response of the system is governed by a set of autonomous highly nonlinear ordinary differential equations. Using an efficient and qualitative analysis exact and lower-upper bound dynamic buckling estimates, very useful for structural design purposes, are established without integrating the aforementioned nonlinear initial-value problem. The analysis is supplemented by a variety of numerical results of a two-degrees-of-freedom dissipative model. From these results it is clearly shown how the point attractor response of the system is changed after a sudden jump to dynamic buckling occurring through a global dynamic bifurcation.