This paper addresses the issue related to forecasting the durability indicators of public transport buses under operational conditions. It has been established that when buses are operated to transport passengers the bus bodies wear at different intensities. During operation, the strength of the body frame weakens under the influence of corrosion in combination with sites of fatigue destruction. As it was established, the intensity of corrosion of the bus body depends on the number of residents in the city where the bus is operated. The earlier established dependences were taken into consideration; the current study has identified two conditional variants of corrosion evolution based on the number of inhabitants: up to 1 million and exceeding 1 million. The expediency of repairs and their impact on the bus passive safety has been analyzed. It was found that the elements of the body frame, without external characteristic damage, no longer meet the specified conditions of strength as a result of sign-alternating loads and during long-term operation. Determining the durability of the bus body was made possible through the construction of a mathematical model. The model’s adequacy was confirmed by road tests of the bus. The devised model describes the movement of the bus over a road surface with different micro profiles, with different corrosion penetration, different loading by passengers, and bus speeds. It was established that the reason for the evolution of structural corrosion is the influence of salt mixtures preventing the icing of roads, as well as ignoring the washing of buses after such trips. It is recommended to use new software for the in-depth study into this issue addressing the combination of various factors of destruction: cyclic loads at variable bus speeds and the corrosion progress. The study results could make it possible to predict a life cycle of the body frame under factors that correspond to actual operating conditions.

The article describes the technological principles of ensuring the durability of bus bodies. Features of technologies on increase of corrosion resistance of bodies of buses of public transport are resulted. The basic tendencies at the modern enterprises on improvement of anticorrosive protection and manufacturing of bodies of buses are considered. New materials for the manufacture of bus bodies are presented. The application of new technologies in the production of small-class bus bodies was introduced in Ukraine in the late 1990s. This was a design development of OJSC «Ukravtobusprom», which was used at OJSC «Cherkasy Bus» since the beginning of production of «Bogdan» buses. The body of the bus «Bogdan» A091, in the process of improvement, received a non-seeded structure, which had a number of significant advantages. The use of glued front and rear fiberglass panels on these buses has significantly increased the corrosion resistance of the bus body. To protect against corrosion of the side panels began to use steel sheets with double-sided galvanizing, which were welded to the uncovered frame of the body. With further improvement of the technology of corrosion protection, the body frame was completely covered with anti-corrosion, highly adhesive soil. In the places of welding of the cladding panels, the frame pipes are covered with heat-resistant conductive soil. Today, galvanized side panels are glued to JSC «Cherkasy Bus» in the production of «Ataman» A092H6/16 buses, which has significantly reduced the number of corrosion cells. At JSC «Ukravtobusprom» the technology of facing of a body provides even less use of steel elements. On TUR A407 and TUR A303 buses, the cladding is made of composite materials (so-called ecobond sheet), which is glued to the frame using Sika technology. Constant improvement of technologies of anticorrosive protection of bodies of buses promotes increase of durability in realities of operation in our state. Because quite often, as real practice shows, operating organizations do not take measures to eliminate the effects of corrosion until the manifestations of structural corrosion, which make it impossible to further operate the bus.

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