Estimation of CZM Parameters for Investigating the Interface Fracture of Adhesively Bonded Joints Under Mode I, Mode II, and Mixed‐Mode (I/II) Loading

• Published in: Fatigue & fracture of engineering materials & structures Vol. 47; no. 12; pp. 4636 - 4649
• Main Authors: Saikia, P. J., Muthu, N.
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01.12.2024
• Subjects: adhesive bonded joints; Adhesive bonding; Adhesive joints; Adhesive strength; Bonded joints; Bonding strength; Cohesion; cohesive zone modeling; Crack initiation; Damage; Error analysis; FEM; Fracture mechanics; Fracture toughness; interface fracture; Interfaces; Mechanical properties; mixed‐mode crack; Parameter estimation; Peak load; Shear
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/ffe.14457

ABSTRACT The mechanical performance of joints for any engineering applications requires accurate characterization of joint interfaces. This paper presents a simplified experimental procedure to estimate the cohesive zone model (CZM) parameters for predicting the interface failure of adhesively bonded joints subjected to mode I (opening) and mode II (shear) loading. The novelty of this procedure lies in predicting all CZM parameters—cohesive stiffness, strength, and cohesive energy (fracture toughness), of the bonded interface using one common experimental setup. It is observed that the cohesive strength and cohesive energy in shear loading are approximately 3.8 and 11.6 times, respectively, compared to the opening loading condition. Employing a triangular cohesive law, the CZM parameters are combined with appropriate damage initiation (quadratic stress) and evolution (power law) criteria. The proposed methodology is verified against experimental load–displacement responses of the bonded interface under mixed‐mode I/II (opening/shear) loading across a wide range of mode mixity (α = 0°, 15°, 30°, 45°, 60°, 75°, and 90°). The maximum error between the experimental and the numerical peak load is 5.11%. The acceptable agreement between the numerical and experimental results confirms the effectiveness of this method in investigating interface fracture in adhesively bonded joints under different loading conditions.