PSI - Issue 47

Yogie Muhammad Lutfi et al. / Procedia Structural Integrity 47 (2023) 660 – 667 Lutfi et al. / Structural Integrity Procedia 00 (2019) 000 – 000

662

3

The model in this study was chosen for two models of stiffened panels on the hull due to the time efficiency of the research process. The reference itself is obtained from ISSC-2000, as shown in Figure 1, which illustrates the cross-section of the bulk carrier. The selection of the models for this study included the stiffened panel on the side and bottom parts of the ship which experienced pressure loadings due to ambient fluid (stiffener numbers 2 and 3) according to Figure 1. 2.2. Geometrical modelling Based on the provided reference in Figure 1, stiffener number 2 and 3 is referenced as light and heavy models which both will be given 100% imperfection (see drawing in Figure 2). Imperfection value refers to the results of the model experiencing buckling to get the ultimate strength value. Making these two models is necessary to compare the ultimate strength results, which are affected by the inertia of the area of each model.

(a) (b) Figure 2. Proposed geometry model in this work: (a) light model, and (b) heavy model.

Boundary conditions in this modeling can be seen in Figure 3. To apply continuous conditions, the longitudinal and transverse edges are set to be uniform. In this modeling, only boundary conditions are given in the form of fixed conditions on the transverse frame without modeling the transverse frame itself. This is enough to get an easy calculation without changing the intent of the calculation itself. The two web nodes in opposite directions will be given axial compression of 5 mm each. In addition, the center point of the plate is also regulated so that it does not experience displacement during the initial application displacements. Element discretization in this work is set to 25 mm in size on the overall geometry. This selection is taken by considering the formed mesh later will appear as a fine element in which each element shape is similar to a perfect square. The choice of mesh size is adjusted to the efficiency of the simulation time to achieve near-accurate results. Images when meshing can be seen in Figure 4.

y = Bay (transverse) z = Height (Vertical) 0=Fixed Uniform = Force work on all nodes

Note: ϴ =Rotation U = Displacement x= Span (longitudinal)

Note: Unit inmm

ϴz = 0 ϴy = Uniform Ux = Uniform Ux = -5 mm

25

ϴz = 0 ϴx = Uniform Uy = Uniform

25

Uy = 0

Z

X

Y

ϴz = 0 ϴy = Uniform Ux = Uniform Ux = 5 mm

Uz = 0

Ux, Uy , Uz = 0

Z X

25

25

Y

25

25

Figure 3. Determined boundary conditions on the finite element model.

Figure 4. Meshing configuration on the panel geometry.