PSI - Issue 37

Behzad V. Farahani et al. / Procedia Structural Integrity 37 (2022) 668–675 Behzad V. Farahani et al./ Structural Integrity Procedia 00 (2021) 000 – 000

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a) b) Figure 6. a) Force – displacement extracted on the loading position and b) force – displacement curves monitored on residual space.

Table 2. Total energy calculated for the bus section.

Deviation * FEM & Experiment

R66 standard Regulation 66 = 12 × 10 3 (J) = 731 (J) Experiment

FEM = 753 (J)

3 %

∗ 100 × ( − )/ . Nevertheless, the studied bus section with the current configuration did not have the potential to pass the R66 standard regulation for rollover test. 4. Concluding final remarks This paper is based on the passive safety protection technology of transit buses subjected to the rollover test. A segment of a-12-m long passenger bus was considered as the case study. The bus section was manufactured and then experimentally loaded following the R66 standard regulations for rollover tests. The force/displacement curve was thereby characterized on the loading position. It must be mentioned that a residual space was considered in the experiment as recommended by the R66 standard regulation. Numerically, the problem was solved using FEM formulations by a dynamic explicit model simulated in ABAQUS © . As a main key, the internal energy was computed for both numerical and experimental analyses and therefore compared to the one recommended by the R66 standard regulation. Regarding the obtained force-displacement curve, it can be inferred that after reaching a certain load applied, the curve experienced a drop that can be justified as a damage or failure occurrence in some parts of the structure. It means that some components had been already yielded which led to reduce the structural rigidity. Therefore, the valid result was considered before reaching this phenomenon. As a summary, it can concluded that this bus structure with the present configuration did not have the potential to pass the essential requirements proposed by the R66 standard regulation for rollover tests. Acknowledgements Dr. Behzad V. Farahani sincerely acknowledges the funding received from Ministério da Educação e Ciência, Fundação para a Ciência e a Tecnologia (Portugal), under grant PTDC/EME-EME/29339/2017. This work was developed in the scope of the project CRASH – Ref. POCI-01-0247-FEDER-039711, funded by "Programa Operacional Competitividade e Internacionalização".