PSI - Issue 64

Visal Thay et al. / Procedia Structural Integrity 64 (2024) 925–931 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 6. Enameled wire installation.

In order to obtain the debonding of the adhesive joints ( P pe_db ), a bending load test was performed on the cantilevered specimen. An enameled wire was used to evaluate the debonding of the adhesive joints. As shown in Fig. 6, enameled wires were attached at 2 mm from the end of the patch plate against the side of the specimen. The load at which the enameled wire failed was taken as the failure load P pe_db . In addition, the debonding of the end of the patch plate was observed using a microscope (Sanko, Dino-Lite Premier). The bending static test is shown in Fig. 7. Fig. 7 (a) shows the scheme of the bending static test and Fig. 7 (b) shows the setup of the bending static test. The tests were carried out under displacement control manually on three specimens for each case.

固定部 Fixed end

Load

延長板

試験体 Specimen

Frame

(a) Scheme of bending static test

(b) Setup of the bending static test

Fig. 7. The bending static test.

4.2. Experimental result The debonding load of the adhesive joint for each case are shown in Table 3. The variation in the test results for each case was evaluated using the coefficient of variation, which was in the range of 0.02 to 0.10, and it was confirmed that the variation in the fracture load of the three specimens were small in all cases. In addition, the debonding load of the adhesive joint for Cases 0 to Case 3 was 3.7, 5.1, 5.3, and 5.0 kN, respectively, as the average of the experimental values for the three specimens. The debonding load magnifications ratio of the test specimens for Cases 1 to Case 3 relative to Case 0 were 1.40, 1.43, and 1.35 times, respectively. Fig. 8 shows the debonding load and the debonding load magnification ratio in the bar graph for each case. Fig. 9 shows the debonding mode of the adhesive joints in each case taken with a microscope at the end of the patch plate. It was confirmed that the failure mode in all cases was cohesive failure.