Dynamic Elastic‐Plastic Buckling Behavior Illustrated by Simple Model

Abstract

A simple model that is imperfection sensitive under quasi‐static compression in the elastic range is studied theoretically and numerically for its elastic‐plastic dynamic buckling behaviors under the half‐sine impact load. For its elastic dynamic buckling behavior, the case of impact load with finite duration is analyzed. The effects of load factors and imperfections on dynamic buckling are discussed. Results show that the critical load magnitude of buckling GD lowers if the duration of the load is longer, and the buckling is imperfection sensitive. For large duration and large imperfection, the model will not reach plasticity but buckle in the elastic range if load magnitude G0 is large enough. The GD is also lower if the extent of strain hardening is greater. When the load magnitude is lower than a critical value Gos that is lower than GD, the model can reach impact shakedown under the repeated impacts. These dynamic buckling behaviors can possibly occur in practical engineering structures.