PSI - Issue 59

B. Ganendra et al. / Procedia Structural Integrity 59 (2024) 238–245 Ganendra et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 6. Final deformation shape of model DT100 with mesh size (a) 20 mm, (b) 10 mm, (c) 5 mm, and (d) 2.5 mm.

According to the result shown in Figures 5 and 6, generally the prediction of final deformation shape of the cylindrical shell models is closer to the deformation occurred during experiment when large mesh size was utilized in the numerical simulation. Conversely, by using large mesh size the shape of the final deformation will be less visible. This means that the numerical simulation will not capture the subtle changes in the shell geometry that occur during the loading process. For an instance, the final deformation shape of model DT150 is nearly the same with the actual deformation when the mesh size was 20 mm which is the greatest mesh size used in the numerical simulation. This indicates that model DT150 is less sensitive to the mesh size variation than other models. Within the following simulation, the mesh size was reduced which result in less visible inward buckling in the midspan of the shell. However, different behavior is shown in other three models whereas the closest final deformation shape prediction is obtained when the mesh size was 10 (see Figures 5 and 6). This suggests that these models require finer mesh size to accurately simulate their deformation patterns. 5. Summary and Conclusions This study aimed to predict the flexural strength of steel cylindrical shell by using numerical simulation. In total, there are four models with D/t ratio ranging from 75, 100, and 125, and studied in this paper. The numerical simulation setup was set to replicate the four-point bending experiment. The data obtained from numerical simulation was later compared with the experimental data and presented in graph. The result reported that the numerical simulation were able to predict the ultimate load of each cylindrical shell model close to the actual ultimate load and revealed the fact that at certain point the ratio of the ( ) ( ) of every model will no longer sensitive to the mesh size, whereas in this study it happened when the value of ratio between mesh size / thickness is 5. Even though the ratio of ( ) ( ) of each model is approximately 1 in all range of mesh size / thickness ratio, there is a certain point on each model where the prediction of the ultimate load ( ) is the most accurate, i.e., the ratio between mesh size / thickness of 10 for model DT75 and DT125 and 5 for model DT100 and DT150. In terms of final deformation shape, larger mesh size is great to predict the final deformation shape of cylindrical shell model whereas in present study, the best prediction of final deformation shape is shown when the mesh size was 20 mm for model DT150 and 10 mm for model DT75, DT100, and DT125. Acknowledgment This work was supported by the Penelitian Kolaborasi Internasional TOP 100 (iTOP-100) – Year 2023 under contract number 3272.1/UN27.22/PT.01.03/2023 in Universitas Sebelas Maret, Surakarta. The authors gratefully acknowledge the support.