Extremal-Micro Genetic Algorithm Model for Time-Cost Optimization with Optimal Labour Productivity

In a highly competitive manufacturing environment, it is critical to balance production time and cost simultaneously. Numerous attempts have been made to provide various solutions to strike a balance between these factors. However, more effort is still required to address these challenges in terms of labour productivity. This study proposes an integrated substitution and management improvement technique for enhancing the effectiveness of labour resources and equipment. Furthermore, in the context of time-cost optimization with optimal labour productivity, an extremal-micro genetic algorithm (Ex-μGA) model has been proposed. A real-world case from the labour-intensive medium-scale bus body fabricating industry is used to validate the proposed model performance. According to the results, the proposed model can optimize production time and cost by 34 % and 19 %, respectively, while maintaining optimal labour productivity. In addition, this study provides an alternative method for dealing with production parameter imbalances and assisting production managers in developing labour schedules more effectively.

Forecasting the durability of public transport bus bodies depending on operating conditions

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.

Comparative TCO Analysis of Battery Electric and Hydrogen Fuel Cell Buses for Public Transport System in Small to Midsize Cities

This paper shows the results of an in-depth techno-economic analysis of the public transport sector in a small to midsize city and its surrounding area. Public battery-electric and hydrogen fuel cell buses are comparatively evaluated by means of a total cost of ownership (TCO) model building on historical data and a projection of market prices. Additionally, a structural analysis of the public transport system of a specific city is performed, assessing best fitting bus lines for the use of electric or hydrogen busses, which is supported by a brief acceptance evaluation of the local citizens. The TCO results for electric buses show a strong cost decrease until the year 2030, reaching 23.5% lower TCOs compared to the conventional diesel bus. The optimal electric bus charging system will be the opportunity (pantograph) charging infrastructure. However, the opportunity charging method is applicable under the assumption that several buses share the same station and there is a “hotspot” where as many as possible bus lines converge. In the case of electric buses for the year 2020, the parameter which influenced the most on the TCO was the battery cost, opposite to the year 2030 in where the bus body cost and fuel cost parameters are the ones that dominate the TCO, due to the learning rate of the batteries. For H2 buses, finding a hotspot is not crucial because they have a similar range to the diesel ones as well as a similar refueling time. H2 buses until 2030 still have 15.4% higher TCO than the diesel bus system. Considering the benefits of a hypothetical scaling-up effect of hydrogen infrastructures in the region, the hydrogen cost could drop to 5 €/kg. In this case, the overall TCO of the hydrogen solution would drop to a slightly lower TCO than the diesel solution in 2030. Therefore, hydrogen buses can be competitive in small to midsize cities, even with limited routes. For hydrogen buses, the bus body and fuel cost make up a large part of the TCO. Reducing the fuel cost will be an important aspect to reduce the total TCO of the hydrogen bus.

Development of Conceptual Design for Electric Bus Body Structure Using Simple Structural Surface Method

An optimum design for a vehicle structure is always desired because the structure can significantly affect the vehicle's performance. However, some complex iterations are usually involved in the designing process. The objective of the present study is to implement the Simple Structural Surfaces (SSS) method for analyzing electric bus body structure that can reduce complexity in the stage of conceptual design. The SSS method model the vehicle structure as several planar sheets and determine the forces in each sheet. Implementing the SSS method at the early stage of the vehicle's development can minimize the number of parameter changes needed during the late stage of development. The results showed that compared with the results obtained from FEM, the SSS method gave the maximum stress value on the chassis in good accordance. Yet, the downside of using this method is that determining the deflections in the structure becomes a little bit complicated. Successfully implementing this strategy can reduce the time and cost required to develop an effective vehicle structure.

Aerodynamic Analysis of VOLVO Intercity 9400 Bus Using CFD

Now a days most of the peoples are using public transport. The main mode of public transport in our country is bus. The availability and price of the fuel are making the public transport to be inefficient and we get only 40% of overall efficiency from any vehicle. It is mainly due to friction. But, friction plays the major role in the stability of the bus. However, we can reduce some unwanted friction like drag and so on., Our main target is to reduce the drag force and to increase the fuel efficiency, which can be done by choosing the best aerodynamic design of the exterior of the bus.The prototype of the bus body has been modelled by modelling software and CFD analysis is done by using analysis software (ANSYS)and it is remodeled to reduce the drag force. These models are named as model 1 and model 2. Model 1 is existing Volvo intercity 9400 bus model and model 2 is modification of existing Volvo intercity 9400 bus. Model 2 is to modify and analyse by using CFD to reduce the drag force, which results in increased performance and reduced fuel requirement.

Technological principles for providing the durability of bus bodies in the production process

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.