PSI - Issue 81

Mohammad Daffa Noorsyahputra et al. / Procedia Structural Integrity 81 (2026) 84–91

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3. Research Methodology 3.1. Geometry model and material properties

The geometry of the trash box is modeled to reflect its actual dimensions and structural configuration, as shown in Fig. 1. The model consists of a base plate and side walls that directly support the operating load. The trash box's effective internal volume of 0,80448 m 3 serves as the baseline design capacity and is used as a 100% reference for all load variations in the analysis. The material utilized is galvanized steel, and its mechanical properties are shown in Table 1. Fig. 2(a) presents the stress – strain curve obtained from a uniaxial tensile test, whereas Fig. 2(b) illustrates a schematic representation of the typical microstructure of a galvanized coating, based on previous studies.

Fig. 1. Geometry model of the trash box.

Table 1. Mechanical properties of galvanized steel (Kamal et al., 2013).

Density (kg.m -3 )

Young’s Modulus ( GPa)

Yield Strength (MPa)

Poisson’s Ratio

7850

210

300

0.3

a

b

Fig. 2. (a) Stress-strain curve of galvanized steel (adapted from Wang and Shao, 2023); (b) schematic microstructure of the galvanized coating (Langil, 2016).

3.2. Boundary condition The applied loads and boundary conditions on the trash box model are shown in Fig. 3. The base plate receives uniform pressure to represent the weight of the stored water hyacinth, while the inner surfaces of the side walls receive linearly distributed lateral pressure along their height. This pressure field represents the load transfer from the stored biomass to the trash box structure under operating conditions. Fixed boundary conditions are applied only to the mounting regions that connect the trash box to the vessel's hull and provide rigid mechanical support, such as brackets or bolted installations. At these locations, all degrees of translational and rotational freedom are restricted, preventing relative movement between the trash box and the hull (Hanif et al., 2023a; 2023b; Malsyage et al., 2025; Melnyk et al., 2025; Rizky et al., 2025; Prabowo et al., 2025).