Longitudinal bending of corrugated sandwich panels with cores of various shapes

The mechanical response of aluminium corrugated sandwich panels with cores of different shapes subjected to longitudinal three-point bending is investigated experimentally and numerically in this paper. The shapes of the core are sinusoid, triangle, trapezoid, and rectangle, respectively. The experimental and simulated results match well with each other. Subsequently, numerical models with specific boundary conditions are developed to simulate the corrugate sandwich panels with an infinite number of core cells. Parametric studies are conducted using these numerical models. The effects of core web thickness, core length, and corrugation angle are investigated numerically. Two deformation modes (Mode I and Mode II) are observed. The panels that deform in Mode I have a larger indentation area and minor global bending. Mode I tends to happen in panels with weaker core webs. Finally, the multiobjective Bayesian optimization method based on lower confidence bound (LCB) criterion is adopted to optimize the geometry of trapezoidal corrugated sandwich panels to improve the specific energy absorption (SEA) and reduce the intrusion depth during the bending.