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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation into the feasibility and application of fibre composites to flatbed semi-trailers

Coker, Rick January 2003 (has links)
The highly competitive nature of the transportation industry has produced significant demand for increased equipment efficiency. This has been manifested in attempts to increase carrying capacity whilst lowering running costs. While these factors remain at the forefront of trailer design, the dependence on steel as the primary material has limited the extent to which these goals are realised. The advantages associated with the use of fibre composite materials in automotive applications have been well documented, demonstrating that the substitution of steel with fibre composite materials greatly increases the scope for tare mass reduction. However, to fully utilise the advantages produced through the use of fibre composites, it is necessary to formulate a design philosophy that incorporates the selection of materials and the definition of acceptable performance of both the material and the trailer. This dissertation addresses this broad subject. Within this greater context, this study addresses the incorporation of fibre composite materials into semi-trailers, with the significant issues being divided into two areas: - The development of a design philosophy, intended specifically to address the application of fibre composites to semi-trailers. - The design, analysis and experimental validation of a new type of fibre composite trailer chassis, utilising the aforementioned design philosophy. This PhD project is a foundational study on the suitability of fibre composite materials in the heavy transportation industry, primarily focusing on a practical assessment of the potential for tare mass reduction. The work presented in this dissertation is seen to provide a basis for fibre composite trailer design, in addition to a foundation upon which further investigation into this field can be made. The major outcomes of this project include, amongst others: - The definition of significant load cases and trailer classifications · The development of a design philosophy suited specifically to FRP semi-trailers - The establishment of selection criteria which identifies appropriate FRP materials for use in this application - The development of a new type of FRP chassis for a flatbed semi-trailer - Validation of the design philosophy through experimental testing - Affirmation of the potential of FRPs in application to flatbed semi-trailers
2

Constrained dynamic path planning for a tractor and semi-trailer vehicle

Mugarza, Imanol January 2015 (has links)
The aim for this project is to design and implement a dynamic path planningmethod for a tractor and semi-trailer vehicle. This vehicle will be in environmentwhich is simulated as a harbour, where containers and other autonomously guidedvehicles are represented as possible objects. Various physical limitations of thevehicle are taken into consideration. For this purpose, a simulator is built, where the environment is reproduced.During the simulation, the vehicle should drive towards the goal avoiding contain-ers and other vehicles, which are sensed by a detection and tracking system. Also,a case study is provided where the functionality of the proposed solution is shownin a given environment. Based on the results of the project, the vehicle computes and follows a tra-jectory towards the goal until a collision is predicted. A new alternative path iscalculated then in order to avoid the obstacle.
3

Safety while handling trailers

Kinik, Ayça January 2012 (has links)
Road transportation grew by 3.3 % per year over the past ten years which is faster than the economic growth of 2.3 % per year. European Commission plans for an increase of 55 % for road transportation between 2000 and 2020. This growth puts pressure on current trucking industry considering fuel consumption, emissions of green house gases, and traffic congestion.  High demand logistics industry and current pressure creates trends towards flexibility and longer vehicle combinations for efficiency and to reduce the number of engines on roads, challenging the current coupling methods of the trailers.  Primary method called 5th wheel coupling comes from a similar coupling used on 4 wheel horse-drawn carriages of the 19th century which is reliable in terms of attaching truck and trailer but has significant safety, efficiency and comfort issues for driver and the vehicles-people around.  So what if hauling setup could be safer and smarter?
4

Long-haulage transport in China : A mapping of segments, needs and future trends for semi-trailers / Fjärrtransport i Kina : eEn kartläggning av segmant, behov och framtida trender för semi-trailers

Tengdelius, Fredrik January 2012 (has links)
This report describes the Chinese truck transport industry; how companies in that industry manage their businesses and the problems they face regarding how they can conduct their long-haulage transport business as efficiently as possible. The method used in this thesis is a qualitative approach where data mainly have been collected through interviews with transport companies. Initially, the components necessary for road transport are discussed, what separates them and how legal demands limit them. Through studies and interviews with transport companies in China and Europe, differences between the different continents are identified in terms of development level and efficiency in logistics handling. These aspects are connected to factors such as salary differences and legislations to finally identify three key segments for the Chinese market. These segments are then analyzed individually and compared against each other to identify one segment where an optimized semi-trailer could improve the current segment and also be an attractive product, for transport companies in that segment as well as for semi-trailer manufacturing companies. Specifications for a proposed semi-trailer are suggested based on needs for that segment. Finally different options for the introduction of such a product at the Chinese market are investigated considering risk-taking, profit requirements and feasibility. This study shows and arguments that there is a big market potential for better semi-trailers than the ones used in the market today and that the segment with the biggest improvement possibilities is a segment where both weight and volume are bottlenecks in the daily business. This study further shows that a high potential can be seen through a growing market and new legislations in China which implies that current semi-trailers will have to be phased out within a period of fifteen years to a product that fulfills the new legislations. / Denna rapport beskriver den kinesiska lastbilstransportmarknaden, hur aktörerna på denna bedriver sin verksamhet och vilka problem de står inför med avseende på att bedriva sin verksamhet så effektivt som möjligt. Använd metod är en kvalitativ approach där data huvudsakligen införskaffats genom intervjuer med transportföretag. Inledningsvis diskuteras de ingående fordonstyper som utgör en bas för lastbilstransporter, deras olika egenskaper, vad som skiljer dem åt och hur lagkrav begränsar dessa. Genom studier och intervjuer av transportföretag i Kina och Europa identifieras olikheter mellan de två kontinenterna vad gäller utvecklingsgrad och effektivitet i logistikhantering. Dessa kopplas ihop med faktorer så som löneskillnader och lagkrav för att slutligen dela upp den kinesiska marknaden i tre segment. Dessa segment analyseras därefter individuellt och ställs mot varandra för att identifiera ett segment där en optimerad semi-trailer dels skulle kunna förbättra det befintliga segmentet men också utgöra en attraktiv produkt för de företag som befinner sig däri, samt för företag som producerar semi-trailers. Specifikationer för den föreslagna semi-trailern läggs fram baserat på behov i det segmentet. Slutligen utvärderas olika möjligheter för att introducera en sådan produkt på den kinesiska marknaden med avseende på risktagande, vinstkrav och genomförbarhet. Denna studie visar och argumenterar för att det finns en stor marknad för bättre semi-trailers än de som marknaden för närvarande använder och att det segment där störst vinst kan göras är ett segment där både vikt och volym utgör flaskhalsar för den dagliga verksamheten. Studien visar vidare att det finns en potential i semi-trailerförsäljning på den Kinesiska marknaden genom förändrade lagkrav vilka kräver att nuvarande semi-trailers byts ut från marknaden inom en femtonårs period och ersätts med nya lagliga.
5

Efektivita využití konceptu EMS v porovnání s jinými způsoby přepravy / Efficiency of the EMS concept in comparison with other modes of transport

Míková, Barbora January 2015 (has links)
This thesis focuses on concept of European Modular System. It describes its characteristics, main advantages and disadvantages and experiences of other countries. A separate chapter focuses on swap bodies so that modular heavy goods vehicles can be compared to them in practical part of this thesis. Aim of this thesis is to evaluate what is better for transport of particular goods, if classical semi-trailer unit with maximum allowed length of 16,5 m, combined transport road-rail with use of swap bodies or modular heavy goods vehicle. Costs, transpotation times and emissions will be compared in this section. The thesis also aims at evaluating if main arguments of opponents of this concept are eligible or not.
6

Třístranně sklápěná korba návěsu / three-sied tipping body of trailer

Peňáz, Jan January 2010 (has links)
This diploma thesis deals with proposal three-side tipping body of tractor semi-trailer with maximum weight 23 tons. In beginning the thesis includes background research part and design of conception body inclusive back door. In the middle part thesis contains the strength calculations using the finite element method, shape optimization and check strength calculation. Strength checks consider especially deformation and strain analysis in different load angle states. The work is finished by analytical calculations included partial body of semi-trailer. Enclosed are graphic illustrations results in program ANSYS Workbench. Part of the thesis is also design documentation. Work is created in co-operation with company ZDT Ltd. Body is designed for universal for multipurpose versatile body carrier Mega 230.
7

Comportamento estrutural de um chassi de semirreboque submetido a manobras relacionadas às dinâmicas lateral e vertical

Boaretto, Joel January 2012 (has links)
A elaboração de projetos de chassi para semirreboques exige a compilação de fatores primordiais à sua aceitação, como atender a requisitos normativos, adequar-se a legislações de trânsito vigentes, conciliar anseios de transportadores e responder adequadamente às excitações das estradas por onde estes irão trafegar. A junção destes requisitos de entrada, geralmente, resulta em limitações estruturais ao semirreboque, neste trabalho destaca-se o fator da restrição geométrica oriunda do sistema de acoplamento da unidade tracionada com a unidade tratora. Esta condição de contorno gera uma região crítica na longarina do semirreboque, suscetível a falhas, que passam por deformações plásticas a trincas transversais que inutilizam o equipamento. O objetivo deste trabalho é estudar o comportamento estrutural do chassi de um semirreboque carregado, segundo legislação vigente, submetido a manobras direcionais relacionadas às dinâmicas lateral e vertical, a fim de avaliar os níveis de tensão atuante frente aos carregamentos impostos. Para isso desenvolve-se uma metodologia de avaliação baseada em acelerações e tensões em pontos específicos do chassi. A sistemática compreende uma análise dinâmica virtual, uma análise estrutural via método dos elementos finitos e uma instrumentação experimental do semirreboque, a fim de calibrar os modelos virtuais. Obtiveram-se resultados de aceleração e deslocamentos para os três tipos de manobra, double lane change, para velocidades de 50, 60 e 70 km/h, costela de vaca, para velocidades 10, 20 e 30 km/h e o slalom para velocidades de 30 e 40 km/h. Os resultados demonstram que, para um carregamento adequado, todas as manobras imprimem níveis de exigência compatíveis com a estrutura proposta. / The project evaluation for a cargo road equipment chassis requires the compilation of key factors to its acceptance as meet regulatory requirements, as adapt to existing traffic laws, reconciling aspirations of carriers and respond adequately the roads excitations of the through where they will travel. The combination of these entry requisites usually results in structural limitations on the semi-trailer, thus this work highlights the geometric restriction which arises from the coupling between the tractor and pulled units. This boundary condition creates a critical region in the road equipment stringer, susceptible to failures, which goes though plastic deformation and transverse cracks that may disenable the equipment. This study aims to investigate the chassis’s structural behavior of a loaded semi-trailer, following the current legislation, submitted to directional maneuvers related the lateral and vertical dynamic in order to evaluate the stress levels acting due to the imposed loads. Therefore, an evaluation methodology based on accelerations and stresses on specific points on the chassis has been developed. The systematic comprises a virtual dynamic analysis, a structural analysis by finite element method and an experimental instrumentation of the semi-trailer in order to calibrate the virtual models. Results were obtained for displacement and acceleration for three kind’s maneuvers, double lane change to speeds of 50, 60 and 70 km/h, cow ribs to speeds 10, 20 and 30 km/h and for slalom speeds of 30 and 40 km/h. The Results shows for a proper loading, all maneuvers show stringency levels consistent with the proposed structure.
8

Comportamento estrutural de um chassi de semirreboque submetido a manobras relacionadas às dinâmicas lateral e vertical

Boaretto, Joel January 2012 (has links)
A elaboração de projetos de chassi para semirreboques exige a compilação de fatores primordiais à sua aceitação, como atender a requisitos normativos, adequar-se a legislações de trânsito vigentes, conciliar anseios de transportadores e responder adequadamente às excitações das estradas por onde estes irão trafegar. A junção destes requisitos de entrada, geralmente, resulta em limitações estruturais ao semirreboque, neste trabalho destaca-se o fator da restrição geométrica oriunda do sistema de acoplamento da unidade tracionada com a unidade tratora. Esta condição de contorno gera uma região crítica na longarina do semirreboque, suscetível a falhas, que passam por deformações plásticas a trincas transversais que inutilizam o equipamento. O objetivo deste trabalho é estudar o comportamento estrutural do chassi de um semirreboque carregado, segundo legislação vigente, submetido a manobras direcionais relacionadas às dinâmicas lateral e vertical, a fim de avaliar os níveis de tensão atuante frente aos carregamentos impostos. Para isso desenvolve-se uma metodologia de avaliação baseada em acelerações e tensões em pontos específicos do chassi. A sistemática compreende uma análise dinâmica virtual, uma análise estrutural via método dos elementos finitos e uma instrumentação experimental do semirreboque, a fim de calibrar os modelos virtuais. Obtiveram-se resultados de aceleração e deslocamentos para os três tipos de manobra, double lane change, para velocidades de 50, 60 e 70 km/h, costela de vaca, para velocidades 10, 20 e 30 km/h e o slalom para velocidades de 30 e 40 km/h. Os resultados demonstram que, para um carregamento adequado, todas as manobras imprimem níveis de exigência compatíveis com a estrutura proposta. / The project evaluation for a cargo road equipment chassis requires the compilation of key factors to its acceptance as meet regulatory requirements, as adapt to existing traffic laws, reconciling aspirations of carriers and respond adequately the roads excitations of the through where they will travel. The combination of these entry requisites usually results in structural limitations on the semi-trailer, thus this work highlights the geometric restriction which arises from the coupling between the tractor and pulled units. This boundary condition creates a critical region in the road equipment stringer, susceptible to failures, which goes though plastic deformation and transverse cracks that may disenable the equipment. This study aims to investigate the chassis’s structural behavior of a loaded semi-trailer, following the current legislation, submitted to directional maneuvers related the lateral and vertical dynamic in order to evaluate the stress levels acting due to the imposed loads. Therefore, an evaluation methodology based on accelerations and stresses on specific points on the chassis has been developed. The systematic comprises a virtual dynamic analysis, a structural analysis by finite element method and an experimental instrumentation of the semi-trailer in order to calibrate the virtual models. Results were obtained for displacement and acceleration for three kind’s maneuvers, double lane change to speeds of 50, 60 and 70 km/h, cow ribs to speeds 10, 20 and 30 km/h and for slalom speeds of 30 and 40 km/h. The Results shows for a proper loading, all maneuvers show stringency levels consistent with the proposed structure.
9

Comportamento estrutural de um chassi de semirreboque submetido a manobras relacionadas às dinâmicas lateral e vertical

Boaretto, Joel January 2012 (has links)
A elaboração de projetos de chassi para semirreboques exige a compilação de fatores primordiais à sua aceitação, como atender a requisitos normativos, adequar-se a legislações de trânsito vigentes, conciliar anseios de transportadores e responder adequadamente às excitações das estradas por onde estes irão trafegar. A junção destes requisitos de entrada, geralmente, resulta em limitações estruturais ao semirreboque, neste trabalho destaca-se o fator da restrição geométrica oriunda do sistema de acoplamento da unidade tracionada com a unidade tratora. Esta condição de contorno gera uma região crítica na longarina do semirreboque, suscetível a falhas, que passam por deformações plásticas a trincas transversais que inutilizam o equipamento. O objetivo deste trabalho é estudar o comportamento estrutural do chassi de um semirreboque carregado, segundo legislação vigente, submetido a manobras direcionais relacionadas às dinâmicas lateral e vertical, a fim de avaliar os níveis de tensão atuante frente aos carregamentos impostos. Para isso desenvolve-se uma metodologia de avaliação baseada em acelerações e tensões em pontos específicos do chassi. A sistemática compreende uma análise dinâmica virtual, uma análise estrutural via método dos elementos finitos e uma instrumentação experimental do semirreboque, a fim de calibrar os modelos virtuais. Obtiveram-se resultados de aceleração e deslocamentos para os três tipos de manobra, double lane change, para velocidades de 50, 60 e 70 km/h, costela de vaca, para velocidades 10, 20 e 30 km/h e o slalom para velocidades de 30 e 40 km/h. Os resultados demonstram que, para um carregamento adequado, todas as manobras imprimem níveis de exigência compatíveis com a estrutura proposta. / The project evaluation for a cargo road equipment chassis requires the compilation of key factors to its acceptance as meet regulatory requirements, as adapt to existing traffic laws, reconciling aspirations of carriers and respond adequately the roads excitations of the through where they will travel. The combination of these entry requisites usually results in structural limitations on the semi-trailer, thus this work highlights the geometric restriction which arises from the coupling between the tractor and pulled units. This boundary condition creates a critical region in the road equipment stringer, susceptible to failures, which goes though plastic deformation and transverse cracks that may disenable the equipment. This study aims to investigate the chassis’s structural behavior of a loaded semi-trailer, following the current legislation, submitted to directional maneuvers related the lateral and vertical dynamic in order to evaluate the stress levels acting due to the imposed loads. Therefore, an evaluation methodology based on accelerations and stresses on specific points on the chassis has been developed. The systematic comprises a virtual dynamic analysis, a structural analysis by finite element method and an experimental instrumentation of the semi-trailer in order to calibrate the virtual models. Results were obtained for displacement and acceleration for three kind’s maneuvers, double lane change to speeds of 50, 60 and 70 km/h, cow ribs to speeds 10, 20 and 30 km/h and for slalom speeds of 30 and 40 km/h. The Results shows for a proper loading, all maneuvers show stringency levels consistent with the proposed structure.
10

Analýza kombinovaných jízdních souprav / European Modular System analysis

Sládková, Nikola January 2015 (has links)
This master thesis is focused on the analysis of economy efficiency of the European Modular System. This determination is going to proceed from comparison of standard and longer trucks. The sense of this thesis is to find out, if standard or longer trucks are more efficient. The comparison is going to be made with the aid of a calculation of costs, which arise on two chosen independent routes. The conclusion evaluation of the trucks is going to work on these analyses.

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