Use of a curved adhesively bonded anchorage for a pultruded composite cable

In order to join a plane composite cable to the main structure of a composite footbridge designed within (Caron, 2009), it was decided to investigate structural adhesive bonding. This technique is indeed particularly adapted to composite materials. However structural adhesive bonding induces stress concentrations at the edges of the adhesive joint, which have been studied by a large number of researchers in order to reduce these phenomena and increase the capacity and service life of the bonded joint (Kinloch, 1987). These studies are all concerned with optimizing shear stress transfer in adhesively bonded joints. This paper investigates the role of hydrostatic pressure on the ultimate capacities of common civil engineering adhesives. The conclusions led us to study a new joint geometry, the "curved" bonded joint that naturally creates compressive stresses on the edge of the bonded joint. Several experimental investigations are presented within this paper to illustrate the optimization. These are quasistatic tests that compare classical shear lap joints to curved joints. Additional testing is currently in progress, but the curved bonded joint seems to hold good prospects and a patent has been filed.