Stability of prebuckled sandwich elastica arches: parametric study

Stability of a newly proposed structural system, namely the prebuckled (prestressed) sandwich arch is investigated. Stability of prestressed elastica arches with sandwich or homogeneous sections are compared through a parametric study of various geometric and mechanical factors by using a nonlinear finite element model. Results indicate that for prestressed sandwich elastica arches the relative thickness and shear modulus of the core layer not only affect the critical load of the arch, but may also change its governing mode of buckling. On the other hand, flexural rigidity of the core layer does not have a significant impact on the buckling load. Also, the bifurcation loads of prestressed sandwich arches increase almost proportionally with the rise parameter of the arch. The category of prestressed elastica arches can be optimized by using sandwich construction since prestressed sandwich arches are shown to be less vulnerable to loading imperfections leading to sidesway buckling. The effects are more pronounced for sandwich sections with thicker and softer cores.