Mechanics of adhesive joints

Summary

Taking into consideration both the pulling and bending actions of the external force, the differential equations for bending of a partly attached tape in a peeling test have been derived. The equations relating the peeling load to the adhesive force were derived under the assumption that the peeling may proceed step by step from the attached end when the adhesive force is overcome by either the tensile stress along the interface (shearing peeling) or that which is perpendicular to the interface (tensile peeling). To verify the validity of the obtained equations, the dependence of the peeling load P on the angle α between the direction of the action of the load and the adhering surface has been investigated using plasticized polymer films. In view of the elementary mechanics, the results were satisfactory, while a modification was attempted by introducing the stress concentration factor.