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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3. FE Analysis

3.1. Analytical model FE analysis was carried out to determine the end shape and dimensions of the specimen used in this study. The general-purpose finite element program used was MSC Marc/Mentat 2022. As shown in Fig. 2, The analytical model consisted of a steel patch plate adhered to one side of the steel base plate, and a linear elastic analysis was performed by applying a concentrated load of 5kN downward to the cantilevered specimen model with one side completely fixed. Elastic analysis of shell elements with perfect bond between steel and adhesive layer were used, and the minimum dimension of the adhesive joint was 0.1mm (aspect ratio of 1). The method determined by FE analysis was based on a model without end design as shown in Fig. 2 (Case 0). In addition to the reference model (Case 0), three other cases were considered: a model using a 30° fillet (Case 1), a model using a 30° reverse taper at the end of the patch plate (Case 2), and a model using a reverse taper with a partially chamfered end of the patch plate (Case 3). An overview of the end design method that was decided is shown in Fig. 3. It should be noted that end design was only performed on the end of the patch plate on the fixed end side. In the FE analysis, it focused on the principal stress generated in the adhesive joint at the end of the patch plate on the fixed end side, and its maximum value was compared for each case.

(a) Analytical model and boundary condition

(b) Analytical model mesh element

Fig. 2. Analytical model of adhesive joints.

Fig. 3. Patch plate end design method and its dimensions.

3.2. Analytical results Fig. 4 shows the principal stress distribution of the adhesive joints by the applied load of 5 kN. 0mm on the horizontal axis of the figure indicates the fixed end, and 40 to 290mm indicates the section of the patch plate. From the figure, the principal stress generated in the adhesive joint is reduced by the patch plate end design. The results of the maximum principal stress from the FE analysis are shown in Table 2. The reduction ratios of principal stress in Cases 1 to 3 compared to Case 0 were 25.5%, 57.4%, and 46.8%, respectively.