| About this Abstract |
| Meeting |
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
| Symposium
|
2024 ASC Technical Conference, US-Japan Joint Symposium, D30 Meeting
|
| Presentation Title |
Evaluating Process-Induced Residual Strains in Multi-Material Single-Lap Joints Using an Experimental Approach |
| Author(s) |
Syed Fahad Hassan, Saratchandra Kundurthi, Suhail Hyder Vattathurvalappil, Mahmood Haq |
| On-Site Speaker (Planned) |
Syed Fahad Hassan |
| Abstract Scope |
This paper investigates the processing-induced strains developed in the adhesive layer of a multi-material single lap joint. High-resolution distributed optical fiber sensors were embedded in the adhesive for in-situ measurement of axial strains and temperatures, developed during the lap joint manufacturing and cooling process. The single lap joints were made of Glass-Fiber Reinforced Plastic (GFRP) and Aluminum Alloy 6061-T6 adherends, which were bonded using a thermoplastic adhesive, Acrylonitrile Butadiene Styrene (ABS). The coefficient of thermal expansion (CTE) mismatch between adhesive and optical fiber results in varying interfacial shrinkage and stresses, leading to interfacial strain incompatibility. The experimental strains recorded by the optical fiber therefore do not represent the actual strains experienced by the adhesive. To overcome that challenge, a detailed thermo-mechanical finite element (FE) model is required that can accurately capture the response of the optical fiber within the ABS adhesive bondline.
To achieve the objective, the project was divided into two parts a) an experimental investigation into the temperature and strain response of the embedded optical fiber and b) validation of the experimentally measured optical fiber strains and temperatures with a high-fidelity coupled thermomechanical FE model. The FE model would then be employed to predict the residual strains and stresses induced in the ABS bulk adhesive during the processing cycle. The current work focuses purely on the experimental investigation of the strain induced in the optical sensing fiber during processing. Bonded joints embedded with optical fiber were subjected to two cooling cycles and the measured strains were compared with the results obtained for GFRP adherend single-lap joints in a previous study. The measured strains were then used to make an analytical estimation of residual strains in the adhesive bondline. A significant increase in experimental strains and analytically calculated residual strains was observed for the multi-material bonded lap joints. |
| Proceedings Inclusion? |
Definite: Post-meeting proceedings |