Effect of laminate tapering on strain distribution in adhesive joints: an experimental investigation

One major problem when using FRP laminates to strengthen and repair structural members is the concentration of stresses in an area close to the end of the laminate which might govern the failure of the joint. One method that has been suggested to reduce the stress concentration in this area is to taper the end of the laminate. Strain distribution in adhesive joints with untapered and normal-tapered laminates has been investigated using experimental method. An optic measurement system, ARAMIS, was used to monitor the strain field in the adhesive layer. The results indicated that normal tapering of the laminate did not affect the shear and principal strain components, while it increased the maximum peeling strain in the joint for the tapering length examined in this study