Buckling of laser-welded sandwich panels. Part 2: elastic buckling normal to the webs

Abstract: This is the first of three companion papers that examine the elastic buckling and collapse of laser-welded sandwich panels with an adhesively bonded core and uni-directional vertical webs. In compression parallel to the webs, the face sheet in between two webs can be treated as a long rectangular plate supported at the sides and resting on a continuous elastic foundation. Using a generalized form of the Kirchoff equation, the plate buckling load is evaluated for a Winkler and Pasternak foundation, and for a foundation model where the core is characterized by an elastic half-space. Although the elastic half-space model is most sophisticated in the way that the decay of transverse stress through the core is described, it requires that the buckling load is calculated iteratively and is therefore not suitable for engineer-ing applications. In contrast, the Pasternak foundation model is able to demonstrate the effect of different boundary conditions at the laser weld and different core properties by the variation of a simple clamping factor and two foundation moduli. By changing the clamping factor, the model can be used to describe plate buckling as well as wrinkling, and, by varying the foundation moduli, it is possible to distinguish between symmetrical and anti-symmetrical buckling modes. Evaluation of the buckling solution shows that, for low modulus core materials