Impact of Laser Texturing on the Shear Strength of the Adhesive Layer between Steel and Wood

In bonded steel–wood composite members, the adhesion between the adhesive and the steel surface is insufficient, thereby affecting the overall shear strength of the composite specimen. This paper proposes creating strip textures on steel surfaces to increase the contact area and embedding depth for the adhesive, thereby enhancing the mechanical performance of the adhesive layer. Laser strip textures of varying widths and depths were carved on steel surfaces. The surface morphology, roughness, and texture depth were measured using a super depth-of-field three-dimensional (3D) microscope system. The contact angle was surveyed with a goniometer, and the distribution of adhesive within the textures was examined using a scanning electron microscope. Based on test data, a finite-element model of a single-lap shear joint was developed, and numerical analysis results were compared with test outcomes to analyze the effect of texture parameters on the shear strength of the adhesive layer. Results indicated that laser texturing altered the failure mode of the adhesive layer in single-lap shear joints and enhanced the shear strength of joints. The finite-element analysis model based on cohesive elements is suitable for optimizing the parameters of laser textures on steel surfaces.