PSI - Issue 52

Leonardo Gunawan et al. / Procedia Structural Integrity 52 (2024) 560–569 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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stiffener part of the experimental specimen is a very rigid part to maintain the shape of the specimen. To model a rigid stiffener, a multi-point-constraint (MPC) is given with a control point that is at half the height of the stiffener In the second model (Model 2), the base plate was perfectly clamped using *TIE constraint to the base frame on its left and right sides only. Meanwhile, the top and bottom sides of the base plate were connected to the frame using cohesive interaction with low stiffness values. This low stiffness value allows the plate to slip w.r.t. the frame and therefore, mimics imperfect bolt fastening. In addition, to capture realistic conditions, only the area connected by the 7 bolts at the top and bottom sides were cohesively connected by cohesive interactions. The bolt was modeled using small circle partition with a radius of 4 mm each with a distance between circle centers of 44 mm. The second model of the base panel can be seen in Fig. 4(b) with detailed depictions of the initial cross-cut on Fig. 5. (a), and the bolt details can be seen on Fig. 5(b). In the simulation the cohesive values between the base plate and the base frame were varied for several values of stiffnesses, namely K = 1, 10, 100, and 1000 N/mm. The meshed model of the base plate can be seen in Fig 5.(c).

Fig. 4. (a) Base panel Model 1; (b) Base panel Model 2.

3.2. Water The cylindrical water container in the experiment with a diameter of 1.5 meters and a height of 1.4 meters was simplified into a box with a square 1.6 m × 1.6 m bottom with a side length of and a height of 1.1 m, while the water height was 0.6 m. This was done to facilitate the formation of meshes and reduce computational time. Water was modeled with Eulerian 3D type with a global mesh size of 10 mm, as shown in Fig. 6(a). The boundary conditions used were Eulerian boundaries with outflow and non-reflective flow types as seen in Fig. 6 (b).

Fig. 5. Detail of (a) cross cut of the center hole. (b) Bolt area for base panel Model 2. (c) Mesh of the base plate.