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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After adding axial compression, the stress obtained by the model will be higher at each step. At step 2:8, experience the ultimate strength of the model. At step 2:8, the model experiences ultimate strength so that the strength of the model is at its maximum level. When the simulation increment is continued, the model will distribute its stress until it cannot be endured. Next is explained for the last step of this simulation, as follows. Step 2:20 is the last step in the model when it is loaded with pressure and axial compression. Based on the results presented in Figure 8, it can be concluded that the stress in the model focuses on the center, which is affected by axial compression. Then, if a detailed observation is made, there are bends in the model, both from the plate, web, and flange. This was influenced by the high stress that the model could not withstand. This phenomenon is called column buckling because all three sections, namely plate, web, and flange, are buckling.

Figure 7. Results of the heavy model simulation for the step (2:8).

Figure 8. Results of the heavy model simulation for the step (2:20).

After analyzing each increment, the results of the heavy model are compiled to analyze the effect of pressure on ultimate strength. As presented in Figure 9, two conditions are given, i.e., pressure and without pressure. It is found that there is a slight difference in the ultimate strength between the two conditions, which specifically occurred in the stress range 250-300 MPa, and strain 0.001 and 0.002. The estimation of this difference is not higher than 5% of overall stress. The structural behavior observed in post-ultimate strength was achieved as closer to strain 0.004, the light model with and without pressures, put the stress was fallen to approximately 190 MPa. An opposite tendency is