Effect of Cohesive Zone Parameters on the Finite Element Method Results of 3D-Printed Single-Lap Joints Using Taguchi Method

Abstract

Additive manufacturing methods are increasingly popular for producing parts with complex geometries due to advantages such as cost reduction and shorter production times. Among these methods, material extrusion is widely used in automotive, aerospace, and biomedical industries for its fast, precise, and low-cost production capabilities. However, the strength of 3D-printed parts remains a critical challenge, primarily due to weak interlayer adhesion, which significantly affects mechanical performance. Previous studies have extensively analyzed factors such as design parameters, adhesive properties, adhesive thickness, and part geometry on joint strength. This study investigates the effects of cohesive zone model (CZM) parameters on the interlayer adhesion strength of single-lap joints produced with a 3D printer. Simulations were conducted using the CZM in Abaqus finite element software and were experimentally validated. The maximum force in the simulation results was obtained at only a 1.35% error rate (1200.1 N in the simulation, 1184.16 N in the experiments). Taguchi analysis was employed to determine the behavior of design factors with a minimal number of simulations. Cohesive stiffness (K), damage initiation (sigma f), and fracture energy (GIIc) were selected as design factors, while maximum force and displacement served as output parameters. Analysis of variance (ANOVA) was used to determine the effect ratio of these design factors on the output parameters. Additionally, the influence of different damage element types, damage stabilization, and fracture energy on the force-displacement behavior of the material was investigated. The results showed that maximum force and displacement increased with higher damage initiation and fracture energy, while cohesive stiffness had a variable effect. Moreover, damage initiation, cohesive stiffness, and fracture energy were ranked in order of their impact on maximum force and displacement.