Adhesive layers are discretized with beam elements.

Strength criterion and stiffness degeneration law of an adhesive layer are proposed.

Sandwich beam obtains maximum strength when angle between the oblique side and the horizontal bonding side of the corrugated layer is 90°.

And when the core has rectangle inner boundaries and the adhesive layers arranged symmetrically along deflection direction.

Crack expands easier in the adhesive layers near the upper and lower panels.