Certification of Buses as per AIS-031/ ECE-R66 Using CAE Methods 2009-26-0001
Bus is one of the major modes of mass public transport in India. Rollover accidents are a major concern for passenger safety in buses. Considering social and economical impact, AIS-031 regulation is being implemented in India from October 2008, which is equivalent to ECE-R66, specifying requirement of strength of superstructure of buses during rollover.
The AIS 031 standard specifies four different methods viz. roll over test on a complete vehicle, roll over test on a body section, pendulum test on a body section and verification of strength of superstructure by calculation. Each method has its own advantages and disadvantages. Application of the standard also needs engineering evaluation of various aspects such as determination of a vehicle family and worst case among that family, which side to rollover, etc. The first revision of ECE-R66 has become effective from February 2006. This revision, though does not affect the requirements, provides more details about the procedures and improves clarity.
As there have been no legal requirements on bus body building in India, there are plethora of designs and variants of the same design in the country. This makes it difficult both for the manufacturers as well as the testing agencies to decide the family concepts and arrive at the worst case. This paper addresses these issues and discusses suitability of the four methods and their practical implementation vis-à-vis ECE-R66-01 - by both computer simulation and physical testing. Issues involved in the validation of the computer simulation by physical testing are also addressed.