This paper deals with the description of the surface texture measurement methods, describes the devices by which the surface texture can be recorded and describes the parameters that allow the surface texture to be quantified. The practical part deals with the evaluation and comparison of the parameters of metric threads M10 made by cutting and forming by analysis of their cross-sections, then the attention is focused on the analysis of pressure forces and torques which occur during the manufacture and in the last part of the thesis there is an economic evaluation of the cost of manufacturing one piece of cut thread.

The thesis deals with an evaluation of the surface texture of various materials, created by machining technologies (turning, milling and grinding). As for the theoretical part of the thesis, it contains a theoretical analysis of the effect of surface texture on friction, wear, coating and lubricating properties. The main emphasis is put on the analysis of the most frequently evaluated profile and surface parameters as well as their possible influence on the functional areas of machined parts. The experimental part includes evaluated and compared measured data based on the monitored parameters with benefits for machinery industry.

This master’s thesis deals with online diagnostics of the machine tool and marginal analysis of surface texture. The first part of the thesis deals with problems theoretically, there are described the machine tools, maintenance, methods of technical diagnostics, specifically online vibrodiagnostic systems and an overview of profile and area parameters. In the practical part, two test samples created under ideal and degraded conditions. In the practical part, two signal processing processes under ideal and degraded conditions are compared using signal analysis from an online vibrodiagnostic system and surface texture analysis. Part of the work is the evaluation of the performed analyzes and recommendations for practice.

The thesis primarily deals with the optimization of laser cutting center for coated aluminium sheet cutting and with the subsequent comparison of measured results and a sample made using waterjet cutting. The thesis is divided in two parts, the theoretical part followed by the practical one. The theoretical section is concerned with the unconventional technologies used, with their general analysis, design, history and utilization for industrial appliances. Main parts of this thesis deals with classification of particular cutting principles and their specific description. The theoretical part contains also classificaton of aluminium alloy, description of surface texture measurement and explanation of basics terms used for roughness measurement. The practical section is concerned with the particular task solution and with all knowledge used for optimization and evaluation of laser cutting. This part contains the measurement results, the measured material, the machines and devices used and also the technical and economical evaluation of this thesis content. The overall evaluation of the laser cutting optimization of specific component is mentioned in the experiment outcome evaluation article.

This master’s thesis includes an overview of profile method of surface texture evaluation according to ISO standards and VDA automotive standards, as well as an overview of areal method according to ISO 25178 standard series, which includes a proposal for improvement of czech terminology. Suitability of application of selected measurement methods for measurement of a portfolio of automotive parts was evaluated based on measurements carried out using a contact profiler, a coherence scanning interferometer and a confocal microscope. Further recommendations for practice in surface texture metrology were also formulated. A regression analysis of the relationship between values of selected profile surface texture parameters and their areal equivalents was also performed. Its results may aid the spread of areal surface texture evaluation in the industry.

Im Beitrag werden bei verschiedenen Lastkollektiven und zwei Reibgeschwindigkeiten die Erodierstrukturen K27, K36, K42 und die Ätzstruktur K36 mit glatten Probekörpern hinsichtlich des Reibwertes und des Verschleißverhaltens untersucht. Als strukturierte Probekörper kommen die Kunststoffe POM und PA und als Gegenkörper zwei verschiedene PE-UHMW´s zum Einsatz. Die Ergebnisse zeigen eine deutliche Abhängigkeit des Reibwertes von der Oberflächenstruktur der Probekörper, jedoch ist die Senkung des Reibwertes stark von den Belastungsparametern Normalkraft und Reibgeschwindigkeit abhängig.

Without lubrication, machines are not imaginable to perform over a long period of time and complete their designated operations. With its omnipresent availability, the air is capable of functioning as a lubricant in long operations very efficiently. Moreover, thrust bearings support axial loads and transmit power at the same time under heavy loads. Therefore, to provide separation under heavy loads in lubricated rotating devices such as thrust pad bearings keeping the power losses at a minimum, film thickness and pressure distribution are very important to investigate at the bearing interfaces. Thrust pad gas (air) bearings are being used in very high-speed rotating machines. Usages of these air bearings are increasing nowadays in industries. In this thesis project, simulations of lubricated contacts of a thrust pad air bearing are performed utilizing multiphysics phenomena and surface textures as mathematical functions. Structural mechanics and fluid mechanics physics are used to model multiphysics functionality. Ideal surface texture models defined by mathematical functions are utilized. More efficient techniques such as homogenization techniques to model the influences of surface roughness are introduced for multiscale study. The current work also presents the Reynolds equation for incompressible and iso-viscous Newtonian fluid flow and formulation for a stationary study. The air bearing with three pads is presented and a virtual twin of this model is built for simulation in COMSOL Multiphysics software. Simulation results are obtained using a single pad from the air bearing considering periodicity of the mathematical formulation. Numerical solutions for pressure build-up and film thickness distributions are achieved from a stationary study performed in COMSOL Multiphysics. MATLAB is used for rigid body solutions. Numerical verification is carried out between the rigid body solutions from MATLAB and fluid physics solutions from COMSOL Multiphysics only for the simulations with tilting pad configuration. Obtained rigid body solutions are also compared to the trends of thrust pad bearing design diagrams to verify the modelling approach and the results. A tilting pad lubricating configuration is used for the thrust pad bearing first. Then pocket geometries for optimization of the bearing pads are explored. For that purpose, separate digital models of the bearing pad are built in COMSOL and analysed for the best performances. Material properties of steel AISI 4340 and Polylactic Acid (PLA) material are used to model virtual bearing pads. To understand the performance of the bearing better, its performance parameters such as load carrying capacity (LCC), relative power loss, and coefficient of friction torque (COT) solutions from the simulations of lubricated contacts of the thrust pad air bearing are analysed. To characterize the performance of the bearing, dimensionless LCC, relative power loss, and COT are explicitly formulated and computed from the pressure and film thickness solutions obtained in the simulations. Relative power loss and COT are resulted from the development of shear stresses in the lubricating fluid due to motion. Parametric analysis is also performed for these parameters in COMSOL Multiphysics. Additionally, performances of several pocket geometry design configurations are also analysed for the best values reached such as the maximum LCC. Pockets with shallower depths are found to have provided higher LCC in general than deeper pocket geometries and plane pads with tilting pad lubricating configuration. Finally, a physical model of an air thrust pad bearing with 3D-printed bearing segments made of PLA material is tested. The physical bearing performed very well in achieving full film separation in the test.

A smooth surface with good friction on the cycle path is not only important for the traffic safety of the cyclists but also for their comfort and level of service. Potholes, cracks, and bumps are frequent obstructions on the cycle paths. These are all maintenance-related deficiencies associated with the degradation of the structure. In general, the knowledge on degradation of roads is good, as there is a long tradition of investigation into the degradation factors. Cycle paths, even though constructed with similar materials and techniques as the roads, are however not designed in the same way as roads, mainly since they will not be subjected to the same traffic load. Thus, one purpose of this licentiate thesis is to identify degradation factors specific for cycle paths, through a state-of-the-art literature study. The literature review is complemented by two papers, where Paper A analyses the distress found on Swedish municipal cycle paths and Paper B evaluates a novel method for condition assessments on cycle paths related to cycling comfort—the Bicycle Measurement Trailer. The review and papers are meant to act as the basis for the general aim of the PhD-project, namely, to develop more knowledge on the degradation of cycle paths. This knowledge is needed to improve the structural design approaches and maintenance strategies for cycle paths and to give guidance for preventive measures to inhibit degradation. / En slät yta, med god friktion, på cykelbanan är inte bara viktig för cyklisternas trafiksäkerhet, utan för deras komfort och framkomlighet. Potthål, sprickor och ojämnheter är vanliga hinder på cykelvägarna. Dessa underhållsrelaterade brister är direkt kopplade till nedbrytningen av cykelvägarna. Generellt sett är kunskapen om nedbrytning av vägar god då det finns en lång tradition av forskning kring nedbrytningsprocesserna. Cykelvägar, även om de är byggda med liknande material och tekniker som vägarna, är dock inte dimensionerade på samma sätt som vägar då de inte utsätts för samma trafikbelastning. Ett syfte med denna licentiatuppsats är således att identifiera nedbrytningsfaktorer som är specifika för cykelvägar. En ”state-of-the-art” litteraturstudie kompletteras av två artiklar, där Paper A analyserar de skador som återfinns på svenska kommunala cykelvägar och Paper B utvärderar en ny metod, Cykelmätvagnen, för tillståndsbedömningar på cykelvägar, relaterat till cykelkomfort. Litteraturstudien och artiklarna är tänkta att ligga till grund för doktorandprojektets övergripande syfte, nämligen att utveckla mer kunskap om cykelvägars nedbrytning. Denna kunskap behövs för att förbättra de strukturella dimensioneringsprinciperna och underhållsstrategierna för cykelvägar och ge vägledning för förebyggande åtgärder som motverkar deras nedbrytning.

Surface quality plays a vital role in controlling the function performance of the workpiece. With the development of the measuring technique, areal surface measurement has been widely applied in the industry. However, estimating the uncertainty of areal surface measurement is still a challenge. Except for the metrological characteristics of the measurement system, measurement conditions should be considered for uncertainty evaluation. The dissertation investigates the influence of measurement settings on surface measurement. A silver-plated surface, three different rough grinding surfaces, and three different rough cylindrical grinding surfaces were measured using structured illumination microscopy. The measurements were at the different objective lenses, vertical scanning interval, exposure time, and sample tilt. The results show that the measurement settings influence the non-measured points, measurement noise, and areal surface texture parameters. Therefore, according to the investigation, the sample tilt and exposure time should also be included in the uncertainty budget. An approach was proposed to investigate the influence of non-measured points on the areal surface texture parameters. The relation between the non-measured points ratio and measurement settings was investigated, and how the areal surface texture parameters changed due to the non-measured points was studied. Moreover, an approach based on the metrological characteristic method was proposed to estimate the uncertainty due to the measurement noise. This method can be extended to the uncertainty evaluation due to other metrological characteristics. Additionally, an approach based on the Monte Carlo Method was proposed to estimate the measurement uncertainty due to different influences. This approach was verified as feasible in the practical measurement.

O desempenho dos pavimentos de concreto asfáltico depende das propriedades e proporções relativas dos seus principais componentes, ou seja, dos agregados minerais, do cimento asfáltico e do volume de vazios. O desempenho das misturas asfálticas de graduação densa é predominantemente influenciado pelas características de forma, angularidade e textura superficial dos agregados finos, que condicionam a estabilidade das misturas. O ensaio de Angularidade do Agregado Fino (FAA), adotado pelo Superpave para avaliar e quantificar a forma, a angularidade e a textura superficial das partículas, tem levantado muitas dúvidas quanto à sua adequabilidade. O objetivo deste trabalho é verificar se o ensaio FAA é capaz de classificar os agregados finos, identificando materiais com melhores condições para utilização em misturas asfálticas. Para tanto, são realizados, além de ensaios de angularidade do agregado fino, análise visual da forma, angularidade e textura superficial, ensaios de cisalhamento direto em amostras de agregado fino e ensaios Marshall em amostras de misturas asfálticas produzidas com diferentes agregados finos. Os resultados obtidos nas análises visuais indicam que o ensaio FAA não é capaz de separar os efeitos de angularidade e de forma das partículas. Os resultados dos ensaios de cisalhamento direto demonstram que um agregado fino com maior FAA não apresenta, necessariamente, uma maior resistência ao cisalhamento. Os resultados do ensaio Marshall também não demonstram correlação da estabilidade com os valores de FAA. Todos os resultados obtidos revelam que o ensaio FAA não é capaz de classificar adequadamente os agregados finos e, desta forma, não é capaz de identificar agregados que proporcionam misturas asfálticas com melhor desempenho / The performance of hot-mix asphalt (HMA) pavements depends on the properties and proportions of the major components, i.e., mineral aggregates, asphalt cement and air voids. The performance of dense asphalt mixtures is influenced mainly by fine aggregate characteristics, such as shape, angularity and surface texture. The Fine Aggregate Angularity test (FAA), adopted by Superpave to evaluate and quantify the shape, angularity and surface texture of fine aggregate particles, has lead a lot of doubts regarding its suitability. The objective of this work is to verify if the FAA test is really able to classify fine aggregates and identify the good ones to be used in asphalt mixtures. Thus, FAA test, visual analysis of shape, angularity and surface texture, direct shear test with samples of fine aggregates and Marshall test with samples of asphalt mixtures produced with different fine aggregates are performed. The results obtained in the visual analyses indicate that the FAA test is not able to separate the effects of angularity from the effects of shape. The results of the direct shear test demonstrate that a fine aggregate with a higher FAA doesn't present, necessarily, a larger shear strength. The values of the Marshall test doesn't demonstrate correlation between Marshall stability and FAA values. All the results show that the FAA test is not able to classify fine aggregates appropriately and, therefore, is unable to identify aggregates that provide mixtures with better performance