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 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
During prolonged storage at low temperatures, meat quality deteriorates due to the activation of the oxidation of unsaturated fatty acids. The use of antioxidants in feeding birds to the prefabricated period and during storage of meat significantly inhibits its oxidative damage and prolongs the terms of storage. Vitamin E is traditionally used as one of the most effective fat-soluble antioxidants. The purpose of the work was conducting a comparative analysis of the effects of high content of vitamin E, depending on the technology of its application, on the oxidative damage of geese meat in the course of low temperature storage. The meat of the first experimental sample was obtained from geese that received feed with twice the content of vitamin E in the pre-slaughter period. The meat of the second test sample was obtained by treating geese meat with a vitamin E solution, before low temperature storage. The results of the experiment proved that regardless of the technology of vitamin E application, it contributes to the inhibition of the oxidative damage. An increase of vitamin E dose in the geese dietary is more effective . The content of secondary lipoperoxidation products in the meat of the control sample stored for 210 days increased by 5.3 times, in the first test sample by 2.5 times, and in the second sample by 4.6 times. An additional use of vitamin E in both studied samples contributed to the preservation of unsaturated fatty acids, but the mechanisms of exposure and changes in the content of individual acids in experimental samples are significantly different.
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.
The object of this study is the permissible limits of aging of bus bodies during operation and the formation of appropriate recommendations to control them based on the conditions of compliance of the body with passive safety rules. According to the current method, the new model of the bus is checked for compliance with passive safety by a destructive method. However, during operation, the physical and mechanical properties of the body deteriorate until the moment of non-compliance with the requirements of passive safety. Therefore, the principles of technical control of bus bodies under the conditions of passive safety by non-destructive methods, the implementation of which became possible during the operation of buses, have been developed. 3 implementation options have been proposed. In the first variant, visual control is complemented by a measuring tool – an ultrasonic thickness gauge for measuring the thickness of the frame pipes. This method has not previously been used in the certification of vehicles. The second option involves checking the mechanical properties during repairs on a breaking machine. It is proved that during the restoration repairs of buses, the endurance limit of the steel elements of the body frame is reduced by 1.14–3.33 times. In the third variant, the methodology for modeling and calculating the stressed-strained state of the body was improved based on the method of finite elements, taking into account the effects of corrosion and fatigue strength of the metal of the frame. When modeling, the deformation of the body racks exceeded the permissible values by 1.5–2.0 times. This non-destructive method makes it possible to check the bus for compliance with passive safety requirements during operation, which was previously impossible. The scope of practical application is the introduction of research results into the real practice of operating buses at the legislative level. The results are suitable for monitoring the technical condition of buses by non-destructive methods during operation
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.