The PI Laboratory has maintained a continuing interest in the development of satisfactory test methods for determining shear characteristics of wood, plywood, adhesives, and more recently sandwich constructions. The anisotropic structure of wood has added to the difficulty of developing test methods that reliably evaluate the desired properties.
This paper presents a brief description of the test methods used, traces the history of some of the methods, and presents a discussion of their advantages, disadvantages, and suitability.
Discussed are the shear and torsion tests for solid wood; the plate shear, panel shear, “rolling” shear, and tubular torsion tests for plywood; the plywood glue shear, wood glue joint shear, metal lap joint and torsion test of adhesives for metals; and the shear tests for sandwich constructions and cores. An analysis of the stress conditions in the test specimens is presented for some of the tests.
