Statistical, Numerical, and Experimental Analysis of Thickness-Graded Adhesive for Enhancing Single-Lap Joint Strength

Document Type : Research Paper

Authors
Faculty of Materials and Manufacturing Technologies, Malek Ashtar University of Technology, Tehran, Iran
Abstract
This research examined the adhesive joint strength between aluminum (Al) and glass-epoxy composite (GL) adherents using graded adhesive through the thickness of the joint (thickness-graded adhesive). Single-lap joints with thickness-graded adhesive were fabricated and subjected to tensile loading. Tensile strength was predicted with finite element simulations employing cohesive zone and shear-damage modeling, and compared with experimental outcomes. Statistical analysis and optimization were performed utilizing response surface methodology (RSM), incorporating total adhesive thickness, adhesive layer thickness ratio, and adherend type as variables. Findings revealed a significant correlation between the shear damage model and experimental results, with adhesive grading enhancing joint strength by 48%. Optimization via RSM indicated that peak tensile force was attained with a total adhesive thickness of 1mm, adhesive layer thickness ratio of 0.85, and GL-GL adherent type.
Keywords
Subjects

Publisher’s Note Shahid Chamran University of Ahvaz remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Available Online from 07 July 2026