In order to design a bus structure, not only stiffness and strength criteria under static and dynamic load conditions, but also crash energy absorption criteria have to be taken into account. Therefore, the rollover phenomenon has to be pointed up due to its importance in accidents in which coaches are typically are involved.
That is why international organizations whose main concern is to regulate such issues are developing important strategies in order to establish new safety standards. An example of such standards in Europe is the Geneva Regulation number 66, which has been developed in order to regulate a minimal rollover resistance for a bus superstructure.
The present paper shows a simulation technique for the roll over test. This technique is based on the Geneva Regulation number 66, which requires a previous validation prior to a new type of bus is released by a company. This paper deal with a test carried out on a representative part of a global bus superstructure behavior and the simulation of this test, by means of applying the developed technique. Results obtained in the simulation showed a high correlation degree with the experimental measurements.
According to these targets, the present paper shows a new concept of lightweight bus completely made with composites, due to its outstanding advantages in the transportation such as the weight saving. This bus structure is able to meet both stiffness and strength requirements, which must be met by traditional metallic buses. The rollover of the composite bus is studied by means of the developed calculation technique and the implementation of adequate material models for the accurate treatment of the special characteristics of composites.
A prototype of the composite bus in the Hispano Carrocera S.A. Company has been developed and manufactured, in order to be tested under several load cases, enclosing dynamic and static measurements with strain gages at representative points.