PSI - Issue 81

Ahsan Anugrah Elbar et al. / Procedia Structural Integrity 81 (2026) 3–10

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3.4. Case configuration

A comprehensive evaluation of the ramp plate’s structural performance was conducted, and three simulation cases were developed to represent various loading scenarios that may occur during operation. The first case applied a uniformly distributed load over the entire plate surface to simulate a steady, static out-of-plane pressure, serving as the baseline condition for comparison. This configuration was essential for assessing the plate's fundamental behavior, including its stiffness, stress distribution, and overall deformation under uniform pressure. The second case introduced a triangularly distributed load, intended to replicate a non-uniform pressure that may result from uneven weight distribution or localized accumulation of materials such as water hyacinth or debris. This simulation helped identify stress concentration zones and deflection patterns as the loading intensity varied gradually across the plate surface, thereby providing a more realistic representation of operational conditions. The third case combines a 150% increase in uniform load with pitting corrosion to simulate the ramp plate under severe mechanical and environmental degradation. In this scenario, the corrosion depth is defined as 30% of the plate thickness, representing a critical level of material loss that significantly compromises the plate's structural integrity. To capture the inherently random nature of pitting corrosion, a Monte Carlo – based stochastic modeling approach was adopted. The statistical distribution of sampled pit depths and a representative realization of the resulting corrosion-induced thickness variation applied to the finite element model are shown in Fig. 5. The pit depth at each surface location was modeled as an independent random variable with a uniform distribution over the range from zero to the maximum corrosion depth. This distribution was selected due to the absence of preferential pit growth data and represents a conservative assumption for advanced corrosion conditions. The spatial variability of corrosion was introduced by randomly assigning pit depths across the plate surface mesh without imposing spatial correlation, thereby assuming statistically independent pit formation. A total of 200 Monte Carlo realizations were generated, each producing a distinct corrosion-induced thickness field. For every realization, the modified thickness distribution was incorporated into the finite element model and analyzed under the intensified loading condition. The structural response of the ramp plate was evaluated in a probabilistic framework by extracting statistical measures from the Monte Carlo simulations. Key outputs include the mean response, standard deviation, and selected percentile values, enabling a more robust assessment of the structural performance and durability under the combined effects of increased mechanical loading and stochastic material degradation.

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Fig. 5. Monte Carlo – generated corrosion modeling: (a) statistical distribution of sampled pit depths; (b) representative realization of corrosion-induced thickness variation over the plate surface. 4. Simulation Result and Discussion The simulation results for the ramp plate under different loading conditions are summarized in Table 4. Under uniform load, deflection increased from 1.38 mm to 4.37 mm, while the maximum stress rose from 12.1 MPa to 38.2 MPa as the applied pressure increased from 50% to 150%. For the triangular load condition, deflection and stress values were significantly lower, indicating that load distribution strongly influences the plate response. The contour plots in Fig. 6 show that the maximum stress occurs near the fixed edges, while displacement concentrates at the plate center. Table 4 also presents the simulation outcomes for the ramp plate subjected to triangular loading. In this condition, both deflection and maximum stress were relatively small, ranging from 8.79×10 -8 mm to 2.56×10 -6 mm and from 8.03×10 -7 MPa to 2.36×10 -5 MPa, respectively. Compared with the uniform load case, the triangular pressure distribution yields lower stress and