A lower bound on snap-through instability of curved beams under thermomechanical loads

作者：Stanciulescu Ilinca^*; Mitchell Toby; Chandra Yenny; Eason Thomas; Spottswood Michael

来源：International Journal of Non-Linear Mechanics, 2012, 47(5): 561-575.

DOI：10.1016/j.ijnonlinmec.2011.10.004

• Snap-through
• Finite element
• Curved beam
• Solid (continuum) elements
• Thermomechanical loads

A non-linear finite element formulation (three dimensional continuum elements) is implemented and used for modeling dynamic snap-through in beams with initial curvature. We identify a non-trivial (non-flat) configuration of the beam at a critical temperature value below which the beam will no longer experience snap-through under any magnitude of applied quasi-static load for beams with various curvatures. The critical temperature is shown to successfully eliminate snap-through in dynamic simulations at quasistatic loading rates. Thermomechanical coupling is included in order to model a physically minimal amount of damping in the system, and the resulting post-snap vibrations are shown to be thermoelastically damped. We propose a test to determine the critical snap-free temperature for members of general geometry and loading pattern; the analogy between mechanical prestress and thermal strain that holds between the static and dynamic simulations is used to suggest a simple method for reducing the vulnerability of thin-walled structural members to dynamic snap-through in members of large initial curvature via the introduction of initial pretension.

• 出版日期2012-6