Metelap Volodymyr

Scopus Publications

DEVISING AN APPROACH TO ASSESSING THE DURABILITY OF BUS BODY ON A FRAME CHASSIS
Dmytro Ruban, Lubomyr Kraynyk, Hanna Ruban, Maria Zakharova, Volodymyr Metelap, Vladyslav Khotunov, and Sergiy Mykhaylyuta
Private Company Technology Center
The object of this study is the processes and permissible limits of aging of bus bodies on the frame chassis during operation. As a result of research by simulation method, the durability of the bus on the frame chassis, was determined, which is in the range from 5 to 11 years depending on the operating conditions. The study took into account the following factors: passenger occupancy, microprofile of the road, bus speed, corrosion. The durability of the bus depends primarily on the durability of the frame and body frame. Since the frame is made of alloy steels and heat-treated, it is not repaired but replaced with a new one when cracks in the frame are formed. When determining the durability of the bus on the frame chassis, it was found that the frame has 1.5–1.8 times greater durability than the body frame itself. This is because the frame is made of alloyed materials and has an open structure. The body frame has closed cavities, which provoke the development of corrosion with the accumulation of moisture in them. A feature of the results is that previous studies considered buses only with a load-bearing body structure. The issue of durability of bodies on the frame chassis has been considered. As experience shows, the durability of bus bodies on a frame chassis depends on many operational factors. For operating organizations and manufacturing plants, it is important to provide for the durability of the bus depending on the operating conditions. The results of this study will allow operating organizations to provide for scheduled repairs, as well as take measures to increase the service life of buses during operation. For manufacturing plants, the findings will make it possible to apply rational technologies and materials to form the service life of the bus body.

DEVELOPMENT OF BUS BODY TECHNOLOGIES IN TERMS OF CORROSION AND DURABILITY
Dmytro Ruban, Lubomir Kraynyk, Hanna Ruban, Maria Zakharova, Sergiy Burmistrov, Vladyslav Khotunov, and Volodymyr Metelap
Private Company Technology Center
The object of this study is the technology of bus bodies and the formation of recommendations for design bodywork subject to the regulated durability of the body introduced into production. Advancing the technology of manufacturing bus bodies implies improving anti-corrosion protection, using new polymeric materials, and reducing the length of welds. The issue of corrosion resistance of bus bodies has been considered. It is established that the use of new polymeric materials will increase the corrosion resistance of bus bodies while existing technologies weakly protect against corrosion (resource up to 5 years). The peculiarity of this study is that the adhesion of new materials has been tested, with artificial aging, which confirms the durability of glued joints. According to the old technology, the body was exposed to anticorrosive treatment after welding the cladding with uncovered places left between the frame and body cladding, which provoked corrosion. The main idea is that in the new technology, the cladding is welded or glued after the body frame is fully coated with primer. New technologies and materials not used in the automotive industry have been proposed. Three variants of technologies were put into production. First: the welding of steel zinc sheets. In welding sites, the frame is covered with conductive primer. It was implemented for school buses (after 7 years, without damage). Second: gluing steel zinc sheets. It was implemented for city buses (after 6 years, without damage). Third: gluing sheets from composite materials not used in the automotive industry. The transition to new adhesive cladding technologies from composite corrosion-resistant materials instead of steel sheet, reduces by 2.5–3 times the length of welds (up to 20 years without damage). The studies have confirmed the strength of glued joints (cohesion rupture exceeds 95 %). The reliability of glued joints and high corrosion resistance of the body have been confirmed in the operation of buses. The scope of practical use of the results: bus-building plants. The reported results are suitable for production of all types while cataphoretic coatings are only for mass production