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

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recorded from the heavy model (see Figure 10), in which after the ultimate point was achieved, the stress behavior was found to decline as the strain approached strain 0.004. The stress of both the heavy models, with and without pressure, was put higher than 200 MPa, even though the model without pressure almost reached the 200 MPa lines. It can be taken as an initial conclusion that the pressure effect is lesser in the proposed heavy model.

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Figure 9. Simulation results of the proposed light model.

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Figure 10. Simulation results of the proposed heavy model.

3.2. Comparison of the FE results and IACS regulation After the FE simulation was completed, a comparative study was carried out to quantify the relationship between the results of finite elements and calculation results using the IACS-CSR [2022]. Based on the data in Table 1, it can be concluded that the ultimate strength value from the simulation results is below the IACS-CSR 2022 value. Additional loading has a negative effect on the ultimate strength value or reduces the ultimate strength value. Approximately, there is a 5% difference for the light model with pressure and 4% for the light model without pressure. This tendency is also observed in the heavy model which the highest distinction between the FE approach and IACS calculation surpasses 10%. Data from this table also indicates that the decreasing ultimate strength value is in line with the small inertia of the area of the model. If the inertia of the area decreases, the ultimate strength will also decrease, or vice versa. Reduction of the ultimate strength is recorded in the range of 4-7% for models without pressures in finite element simulation, and 1.5% for the calculation using IACS-CSR regulation.