PSI - Issue 42

Rogério Lopes et al. / Procedia Structural Integrity 42 (2022) 1159–1168 Rogério F. F. Lopes et al./ Structural Integrity Procedia 00 (2019) 000 – 000

1162

4

a)

b)

Fig. 1. Procedure to perform the ECE R29 test: a) frontal impact (test A) and b) mannequin to test the survival residual space according to standard regulation of R66 2. Model definition Welding is used to join the profiles and components, creating a rigid frame. Many components deemed to be significant in energy absorption were added to the chassis. It is also vital to employ the outer fiberglass panels, windshield, and certain side metal plates. The test bench attachment must be as simple as possible, eliminating the front axle and suspension systems. As a result, the structure completely absorbs the impactor's energy with no losses via the other bus body components. This method will result in a significant simplification of the tested structure as well as significant design cost reductions, Fig. 2.a-b), (Lopes et al., 2022b). The manufactured stiff component employed to anchor the superstructure is seen in Fig. 2.c). Due to the lack of a front axle on this prototype, the fixation is instantly replaced by a rigid connection to the ground. This connection type takes use of the structural floor's perforations being spaced 1000 mm apart, resulting in a 3x3 matrix pattern. This option allows the structure to be fastened without the possibility of energy losses due to chains, making the construction more stable.

a) c) Fig. 2. Section to be tested according ECE 29 regulation: a) side view of R-29 test section of ≈ 3.9 length, b) experimental coach section and c) chassis of the section developed for ECE 29 test The vehicle substructure was designed mostly with tubular parts for the frame. The procedures employed to manufacture this prototype are the same as those used to develop the original chassis. This one contains a tiny cast iron component that enhances the rigidity of the construction in the event of a collision. In this case, the component was replaced by four square-section tubes to replicate the original component stiffness as closely as possible. As a result, the following conditions were met: the involved welding process was MIG/MAG; the dimensions and tolerances of the chassis were in agreement with the manufacturer; development of the front platform by MIG welding of square section tubes; panels and the roof followed the same attachment techniques; the chassis welding was in accordance to the manufacturer restrictions; the steering column fixture by two semi-curved clamps; installation of seat and steering wheel; plywood floor at the entrance; application of aluminium sandwich panel and PET core in the passenger area and assembly of the fiberglass dashboard manufactured using manual moulding. b)