Effect of Loading on the Snap-through Response of a Post-buckled Beam

摘要

Snap-through response is a post-buckling phenomenon, which results in large amplitude motion between the equilibrium configurations. This paper provides some observations on snap-through response of a flat-beam specimen through both experiments and simulations based on experimentally motivated parameter values. The effect of static (thermal) loading and dynamic loading is investigated for its effect on snap-through response. It is shown that snap-through response frequency increases with increasing dynamic load but decreases with increasing static load. Further, snap-through response amplitude increases both with increasing dynamic load and with increasing static load. This research analyzes the characteristic of snap-through response frequency and suggests that the paradigm of intermittent and persistent snap-through should shift to a snap-through response frequency spectrum. A reduced-order modal model of the flat beam is used to numerically estimate a snap-through boundary in the parameter space of loading. These results contribute to the development of an analytic snap-through boundary. Although a conservative estimate for this boundary can be obtained via energy principles, this research seeks to establish a detailed characterization of snap-through response such that it could lead to design criteria for non-conservative aerospace structures. A sensitivity analysis is then conducted on the snap-through boundary. This analysis includes variations in linear stiffness, nonlinear stiffness and damping.