اميرحسين روحي

With the growing use of adhesive joints, the need for an optimized method that provides low-cost, accurate, and simple tests to eva‎luate failure in these joints has become increasingly evident. Existing tests for analyzing the fracture behavior of adhesive joints, such as the Double Cantilever Beam (DCB) test and the End-Notched Flexure (ENF) test, have several disadvantages. These include high testing costs, nonlinear behavior, large specimen sizes, unstable crack growth, difficulty in monitoring crack propagation due to minimal crack opening and displacement (sliding between two surfaces) during the fracture process, friction between crack surfaces, premature adhesive failure, and the complexity of the tests. Additionally, these tests do not cover all mode mixity ratios. Therefore, in this study, for the first time, the fracture characterization of adhesive joints was investigated using the Short Beam Bending (SBB) test under shear-dominated loading, employing the Compliance-Based Beam Method (CBBM). The SBB specimen has a simple and uncomplicated geometry, low manufacturing costs, and requires basic laboratory equipment. By adjusting the position of the supports, all mode mixity ratios can be covered. To ensure the accuracy of the derived formulations for the SBB test, ENF and SBB specimens were fabricated and tested under Mode II fracture loading using the same adhesive and adherends. The fracture energy was calculated using the compliance-based method (CBBM) for both the ENF and SBB tests and compared. A good agreement was observed between the new specimen and classical energy measurement methods, with a fracture energy difference of about 8.9%. Finally, to validate the calculations, ENF and SBB tests were simulated using Abaqus software. The traction-separation law parameters were determined as input parameters using an indirect method. After the simulations, the load-displacement curves were obtained from the software, showing a strong correlation between the experimental and numerical load-displacement curves.

اتصالات چسبي , آزمون شكست , مود دو شكست , نرخ آزادسازي انرژي كرنشي , مدل ناحيه چسبنده

Adhesive joints , Fracture test , Fracture Mode 2 , strain energy release rate , Cohesive Zone Model

Amir Hossein Roohi

Dr.Hadi Khorrami Shad