Volume 20, Issue 4 (July 1992)
Fracture Testing Wood Adhesives with Composite Cantilever Beams
A new approach to evaluating wood-adhesive joints is being used by the Wood Adhesives Science and Technology Research Work Unit at the Forest Products Laboratory. This test involves the measurement of adhesive fracture toughness in Mode I cleavage. It is an extension of the contoured double cantilever beam (CDCB) test developed by Mostovoy and others  and generally follows the procedures outlined in ASTM D 3433 . Samples are prepared by bonding thin wood laminates to contoured aluminum beams. The addition of a laminate to the aluminum adherends significantly reduces the change in linear compliance with crack surface area (dC/da) of the composite, thereby influencing the calculation of fracture toughness. This effect is established both experimentally and theoretically.