Framework for constructing bus superstructure based on UNECE R66 Annex 9

Since ages, buses are the most prevalent mode of transportation around the world due to its affordable cost and accessibility. Among all the types of bus accidents, the rollover is the most dangerous. A regulation known as United Nations Economics Commission for Europe (UNECE) Regulation No. 66 regarding the strength of the bus superstructure in case of rollover has been legislated and implemented by many countries including Malaysia since 2007 following the horrendous bus accident which claimed 22 lives in Bukit Gantang. Although the regulation is legislated, however, the specific guideline of constructing the bus in Malaysia to meet the regulation’s requirement is considered insufficient or almost towards nonexistence. Since testing the rollover of the complete bus consumes huge expense, many opt for computer simulation which is also approved in R66 as Annex 9. The aim of the work is to prepare a framework of constructing bus superstructure that can survive the impact of the rollover without interrupting the residual space using three different materials which are standard mild steel, ASTM A500 Grade B steel and AS1163 steel with ultragal coating and simulated with FEA software, LS Dyna. For this purpose, a standard single decker bus model is used with the length, width, and height of 11525mm, 2450mm and 3840mm. The bus uses square hollow section (SHS) and rectangular hollow section (RHS) pillars and is considered to have unladen kerb mass which is not having any passengers’ weight. A few parameters are selected to be altered including the dimension and thickness of the pillars, and installation of the additional support at the corner of the roof to find the minimum condition where the residual space is preserved during the rollover. As a result, the dimensions of the ring pillars are widened to 60x60 mm, and large supports are added at the roof corners. The differences for each material are the thickness of the ring pillars and the lower structure. For the mild steel, the ring pillars are changed to 5.0 mm except for the last ring pillar which is 6.0 mm and 3.0 mm for the lower structure causing the weight to increase as much as 0.6805 tonne. For the ASTM A500 Grade B is 4.0 mm and 5.0 mm for the last ring pillars while all ring pillars are set at 3.0mm thickness for AS 1163 with ultragal coating material. The thickness of the lower structure remains unchanged at 2.3mm and the increment in weight are 0.271 tonne and 0.0088 tonne respectively. After the modification, the residual space is unharmed with the clearance between the ring pillars and residual space are 13.8mm, 15.6mm and 6.3mm for standard mild steel, ASTM A500 Grade B and AS1163 with ultragal coating. Therefore, the minimal thickness of the ring pillars required to pass the UNECE R66 for standard mild steel is 5mm, ASTM A500 Grade B is 4mm and AS1163 is 3mm with the dimension 60x60 mm. These combinations of measurements can be used as a framework to construct the bus in future to reduce the fatalities and injuries of the passengers and driver in rollover accidents. Furthermore, a survey was conducted among the eleven bus manufacturers to get a grasp on their awareness towards R66 and the implementation of the regulation in their company. From the survey, only 58.2 percent are aware about the R66. The common materials used for bus making as well as the dimensions and sizes are also included in the survey.

Text FK 2023 36 - Declaration Form.pdf Restricted to Repository staff only Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (554kB) Text FK 2023 36 - Full Text.pdf Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (10MB) Text FK 2023 36.pdf Restricted to Repository staff only Available under License Creative Commons Attribution Non-commercial No Derivatives. Download (10MB) Official URL or Download Paper: http://ethesis.upm.edu.my/id/eprint/18956

Actions (login required)

View Item