The topic of this thesis is springing of front driving axle design in Zetor tractor of series Proxima including FEM analysis. The thesis also deals with study of currently used suspended front axles produced by word known manufacturers.

This diploma thesis deals with creation of computational model of AZUB recumbent tricycle composite axle for stress strain analysis. The thesis consists of four main parts. The first part contains introduction to the offer of full suspended tricycles from the most known manufacturers. Furthermore it contains introduction to composite materials that makes the main element of AZUB´´s suspension, and the description of the AZUB´´s front axle. In the second part there is detailed compilation of computational model for purpose of stress strain analysis of three load states. The effect of specific material and geometry parameters on axle behavior is discussed with the aim of choosing the most appropriate variant. Third part deals with the manufacturing of the front axle prototype and with tests leading to input data for numerical model and verification of computational model. Modifications and changes that lead to manufacturing of the second prototype are content of the last part. Based on this experience some recommendations for future development of the numerical axle model and the front axle suspension itself are formulated.

The goal of this thesis is structural design of the trailer for a LASKI chippers and to create a construction drawings. Important part is information about legislation rules, which this trailer has to fulfill. The aim of this work is to do a dynamic simulation using multi-body system. Results of this simulation are used for a stress analysis witch using a fine element method.

The diploma thesis deals with examinations of forces which are acting from road surface on tyres. The aim is to design and build measuring circuit which measure forces in front suspension. The thesis deals with designing of mathematical model in addition describes problematic of strain gauge sensors, their calibration and verification measure in details. The results are data obtained from static and dynamic measurement and outputs from multi-body system softwares. The results are evaluated and compared at conclusion.

Besides the braking system the steering system is one of the most important systems on vehicles. The reliability and the performance of a steering system decides on the controllability of the vehicle under normal conditions as well as emergency situations. In everyday use the characteristics, the connectivity to assistance systems and the energy efficiency of the steering system become more and more important to fulfill the increasing demands regarding fuel consumption, carbon dioxide emissions and comfort. To meet these demands, new steering systems must be implemented and new technologies have to be developed. This contribution compares different approaches regarding functionality and energy efficiency to give an indication which system is the most promising solution for future front axle steering systems as well as rear steered axles (tag- or pusher axle) on trucks.

Dot peen markings are used by Scania Ferruform to maintain a traceability of their products throughout the manufacturing. Quality inspection of the markings are performed to ensure that they are added correctly and readable. This is, however, done manually by workers, which they are looking to change. Machine vision, in combination with machine learning, could prove helpful in automating this process, which is where this thesis comes in. Images of two types of dot peen markings were gathered using different experimental setups and equipment. Amazon Rekognition and MVTec Halcon were both used to predict the characters of the images, in order to determine if the two systems could be used to demonstrate that the quality inspection can be automated. To improve the result, the images were also processed with varied techniques. The pretrained version of Amazon Rekognition and MVTec Halcon, with unprocessed image, performed the best. They both predicted all the characters correctly, and showed a high confidence in their predictions, with an average confidence of 96.41% and 99.87% respectively. When processing the images before predicting the confidence of the systems decreased and predictions were also made incorrectly. Custom training a model also showed a poor result, with the best combination of average precision and overall recall being at 0.733 and 0.561 respectively.

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The need for modern transportation systems together with the high demand for sustainable pavements under applied loads have led to a great deal of research on concrete pavements worldwide. Development of finite element techniques enabled researchers to analyse the concrete pavement under a combination of axle group loadings and environmental effects. Consequently, mechanistic approaches for designing of concrete pavements were developed based on results of finite element analyses. However, unpredictable failure modes of concrete pavements associated with expensive maintenance and rehabilitation costs have led to the use of empiricalmechanistic approach in concrete pavement design. Despite progressive knowledge of concrete pavement behaviour under applied loads, concrete pavements still suffer from deterioration due to crack initiation and propagation, indicating the need for further research. Cracks can be related to fatigue of the concrete and/or erosion of materials in sub-layers. Although longitudinal, midedge and corner cracks are the most common damage modes in concrete pavements, Austroads method for concrete pavement design was developed based on traditional mid-edge bottom-up transverse cracking introduced by Packard and Tayabji (1985). Research presented in this thesis aims to address the most common fatigue related distresses in concrete pavements. It uses comprehensive finite element models and analyses to determine the structural behaviour of concrete pavements under vehicular loads and environmental effects. Results of this research are supported by laboratory tests and an experimental field test. Results of this research indicate that the induced tensile stresses within the concrete pavement are significantly affected by vehicle speed, differential temperature gradient and loss of moisture content. Subsequently, the interaction between the above mentioned factors and concrete damage modes are discussed. Typical dynamic amplifications of different axle groups are presented. A new fatigue test setup is also developed to take into consideration effects of pavement curvature on fatigue life of the concrete. Ultimately, results of the research presented in this thesis are employed to develop a new guide for designing concrete pavements with zero maintenance of fatigue damage.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Road Tra c legislation prescribes constraints on the forces/loads which vehicles may exert on the road at contact surfaces or load points. These constraints have bearing on speci c contact surfaces or groups of contact surfaces. The constraints are in the form of maximum force values and maximum ratios, which may exist between forces. The forces exerted by a vehicle on the road is determined by a combination of the vehicle's own mass, dimensional characteristics, and the mass and position of its cargo. The mass and position of the cargo can be modelled by only considering its centroid. The centroid's position is linked to a certain cargo arrangement. It is necessary, in terms of legal constraints, to distinguish between legally permissable- and non-permissable arrangements. Methods are proposed in this dissertation to determine the borders for the position of the centroid according to cargo-mass, for a variety of vehicle con gurations. The determination of borders for the position of the centroid is the result of a three part process. Firstly, the legal limits are translated to mathematical inequalities that must be satis ed for the forces at contact surfaces. Secondly, conservative parametric estimates for the forces, in terms of the position and the mass of the centroid of a given vehicle, must be derived. Finally these estimates are incorporated into the load constraints and an enclosed permissable area for the centroid is found. These position constraints are suitable inputs to solution methods of various cargo arrangement problems. Linear programmes which can solve certain general arrangement problems by utilising the position constraints on the centroid, were successfully developed. Solutions are presented for the arrangement of pallet-freight, as well as the arrangement of cargo units with asymetrical centroids over the length or width of a vehicle's cargo area. / AFRIKAANSE OPSOMMING: Padvervoerwetgewing skryf grense op kragte/laste voor wat voertuie by kontakoppervlakke of laspunte, op die pad mag uitoefen. Hierdie voorskrifte het betrekking op spesi eke laspunte en groepe van laspunte. Die voorskrifte is in die vorm van maksimum laswaardes by laspunte en maksimum ratio's wat tussen sekere laste mag bestaan. Die laste wat 'n voertuig op die pad uitvoer word bepaal deur 'n kombinasie van die voertuig se eie massa, dimensionele eienskappe, sowel as sy vrag se massa en posisie. Die vrag se massa en posisie kan gemodelleer word deur slegs die massamiddelpunt daarvan te beskou. Die massamiddelpunt se posisie word gekoppel aan 'n bepaalde vragrangskikking. Dit is nodig om, in terme van wetlike voorskrifte, te kan onderskei tussen wetlik toelaatbare en -ontoelaatbare rangskikkings. Metodes word in hierdie proefskrif voorgestel waarmee daar grense vir die posisie van die vragmassamiddelpunt bepaal kan word na gelang van die vragmassa, vir 'n verskeidenheid van voertuigkon gurasies. Die bepaling van grense vir die posisie van die vragmassamiddelpunt is die resultaat van 'n drieledige proses. Eerstens word die wetlike beperkings herlei na wiskundige ongelykhede waarbinne laste by kontakoppervlakke moet val. Tweedens word konserwatiewe parametriese beramings vir die laste verkry in terme van die ligging en massa van die vragmassamiddelpunt vir 'n gegewe voertuig. Laastens word hierdie beramings in die lasbeperkings opgeneem om 'n afgebakende toelaatbare gebied vir die vragmassamiddelpunt se posisie te verkry. Hierdie posisiebeperkings is geskik om as inset te dien in die oplossingmetodes van 'n verskeidenheid van vragrangskikkingsprobleme. Line^ere programme wat sekere algemene rangskikkingsprobleme kan oplos deur die aanwending van posisiebeperkings op die vragmassamiddelpunt, is suksesvol ontwikkel. Oplossings word aangebied vir die rangskikking van paletvrag, asook die rangskikking van vrageenhede met asimmetriese massamiddelpunte oor die lengte of breedte van 'n voertuig se vragarea.

Volvo Construction Equipment is highly regarded for robust products, but with an increasing competition in their market, development of the product portfolio is more important than ever. One step being carried out is to reduce losses in powertrains and increase the fuel efficiency for solutions such as articulated haulers and wheel loaders. This would eventually lower the fuel costs and emissions for the end customer. With this development, Volvo CE could strengthen their position in the market while also contributing to reducing the construction industry's environmental impact. By investigating the front bogie axle of the recently introduced hauler, Volvo A60H, important information about possible reductions and the distribution of the current losses were found. The investigation focused on a front bogie axle, but some of the results are applicable for other applications such as wheel loaders as well, since a lot of the technology in the axles are similar. A conceptual study was performed where completely new ideas were generated, such as implementing a dry sump system in the axle, as well as ideas for improving the subcomponents currently found in the axle. Two cases were presented for the evaluation of concepts, one with a fully loaded dump body and low speeds, and one with an unloaded dump body and a wider speed interval. The concepts were later evaluated using calculation tools such as MATLAB and a Simulink-model was created for the losses in the axle. When combining concepts that reduces load dependent losses, a potential reduction of 64% of the axle's total losses was achieved for the case with a full dump body. The largest improvement found for the load independent losses was 8% with an unloaded hauler and the highest speed investigated, 50 km/h. A dry sump system improves the axle's efficiency with 45% in optimal working conditions, but was found to lower the efficiency at other conditions. Room for improvement of axle losses currently exists both for load dependent and load independent losses. The evaluation performed pointed towards the load dependent losses being the largest influence on the total losses, even with an unloaded dump body and high speeds. This is an interesting observation since a lot of work at Volvo CE has revolved around reducing the load independent losses since these are easier to affect with different lubrication levels and rotational speeds. A test methodology for load dependent losses should be implemented in order to validate the results of this thesis work, and also to aid further development at Volvo CE.