PSI - Issue 61

João C.M. Santos et al. / Procedia Structural Integrity 61 (2024) 79–88 Santos et al. / Structural Integrity Procedia 00 (2019) 000 – 000

83 5

E 1 [MPa]

44028.7

7854.8

2.3. Numerical modelling The numerical models were developed in Abaqus ® . To simplify the procedure while guaranteeing accuracy of the results, a 2D representation of the geometry was chosen. A CZM with triangular shape traction-separation law is used to simulate failure in the adhesive layer connecting the hull to the deck. The materials, both the hull and the deck, are linear elastic and orthotropic. A thickness of 0.2 mm was considered for the adhesive. The adherends were dimensioned for a length of 50 mm. In terms of thickness, the deck adherend is 3.6 mm thick, while the hull adherend is 4.2 mm thick, centered on each other, i.e., with 0.3 mm offset on each side. The joint was subdivided into sections to allow the differentiation of each material and the subsequent attribution of their distinct properties. For the PVC core, a thickness of 3 mm was assumed, while for the GFRP and CFRP, a thickness of 0.3 mm was considered for each layer. For each section, the mechanical properties and their respective behavior were defined from the data of Table 1, Table 2 and Table 3. PVC, CFRP and GFRP were defined as homogeneous solid materials, while the adhesive was defined as a cohesive material. Boundary conditions were established to emulate different possible loadings applied to the joint. To this end, a geometric restriction (encastre) was applied to the lower adherend, while a displacement condition depending on the loading scenario was applied to the upper adherend (Fig. 5). CPE4 elements were used for the adherend layers, while one row of finite thickness COH2D4 elements was used for the adhesive, both with full integration. Bias (size grading effects) in the constructed mesh ensured good refinement at the most critical locations to extract the stresses at these locations more accurately. Additionally, the cohesive element size was considered to be equal to 0.2×0.2 mm 2 and the solid elements in the adhesive layer surroundings were generated and propagated by means of partitioning following this geometric rule. This strategy has proven in previous works that the results would be accurate without the need for more refined elements (Rocha and Campilho 2018). A convergence analysis on SLJ was carried out by Campilho et al. (2011), which corroborated these findings. The triangular shape traction-separation CZM model is described by Rocha and Campilho (2018). In Fig. 6 is presented the mesh for each corresponding joint geometry analyzed in the numerical work and the detail view of the adhesive layer region.

Fig. 5. Boundary conditions of the numerical study: a) traction; b) compression; c) bending; d) shear.