Dynamic elastic-plastic buckling of circular cylindrical shells under axial impact
The understanding of dynamic elastic-plastic buckling phenomena of thin walled ductile metal tubes is especially of great practical importance when one considers energy absorbing properties. Although there exist a number of investigations of this phenomenon, some aspects are still poorly understood due to their complexity and due to the presence of parameters. In particular, the initiation of the buckling as a transient process has so far received little attention, and is studied in the present paper for variations of velocity of impacting mass on a large interval. This allows to clarify the influence of elastic and plastic stress waves on the initiation of buckling, and to provide some insight into post-buckling behaviour. The authors use a discrete model where springs are used to simulate the elastic-plastic material properties. A strain rate insensitive elastic-plastic material with linear strain hardening and displaying Bauschinger effect is assumed. The highly nonlinear system of equations is integrated numerically using a BDF method. Simulation results are compared and shown to be in good agreement with experiments performed on aluminium alloy tubes. The most important findings of the paper are that the dynamic buckling process is governed by stress wave propagation effects, and that the entire length of shell is involved in the deformation process for a high-velocity impact. Moreover, the final buckled shape depends strongly on inertia properties of the striker, and on the geometry of the shell. A thorough discussion of these and many other findings is presented in this excellent paper.
strain-rate insensitive elastic-plastic material
scientific article; zbMATH DE number 1485124