Effects of geometrical modifications on behavior of adhesive joints used to bond CFRP laminates to steel members - experimental investigation

Paper in proceeding, 2009

One major problem when using FRP laminates to strengthen and repair flexural members is the stress concentration in an area close to the end of laminate which might govern the failure of the strengthening. A method that has been suggested to reduce the stress concentration in this area is to modify the geometry of the adhesive joint by tapering the laminate end and or adding an adhesive fillet. This paper presents the results of a comprehensive study on effects of geometrical modifications on behavior of adhesive joints carried out at Chalmers University of Technology. The focus of this paper is on the strain distribution in adhesive joints with untapered and normal-tapered laminates since the results from normal tapering of the laminate showed negative effect of tapering on strength of joints. An optic measurement sys-tem, 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