Effect of surface preparation technique on bond behavior of CFRP-steel double-lap joints: Experimental and numerical studies

Abstract An experimental program was conducted to evaluate the performance of various CFRP-steel double-lap shear (DLS) joints in terms of strength, failure mode, load–displacement behavior, and interfacial shear stress distribution. The variables studied through this program are: (i) surface preparation method, (ii) CFRP/adhesive system, and (iii) bond length. Non-linear finite-element models were developed to simulate the behavior of specimens with different failure modes. From all considered configurations, grit-blasted specimens with strand sheet CFRP exhibit the highest strength, maximum displacements, and interfacial shear stresses. In this configuration, specimens exhibited mixed interfacial/cohesive failure. In all other configurations, specimens failed at the adhesive-steel interface.