Wood Shear Panels Bonded with Flexible Adhesives

The influence of adhesive rigidity on the stress distribution in a prefabricated plywood wall panel subject to a racking load has been investigated. A typical low-cost housing wall panel, joined by means of a thick-layer adhesive, was studied analytically and experimentally. The results of stress analyses of the panel were performed with two different adhesive rigidities-a rigid adhesive and a relatively flexible adhesive. For each analysis, the stresses in the plane of the sheathing were compared. The analytically predicted critcal rolling shear stress between framing and sheathing was found to be three times greater in the panel joined by the rigid adhesive than in the panel joined by a flexible adhesive. The flexible adhesive serves to reduce stress concentrations by distributing loads uniformly throughout the structural system. The results of a limited testing program partially substantiate the results of the analytical study. A wall panel was fabricated and constructed with a material similar to a flexible thick-layer adhesive. The agreement was good which in part substantiates the conclusions drawn from the finite element analysis.