I en kantviksmaskin som används för plåtbockning sker oönskade deformationer i mekanismen som klämmer fast arbetsmaterialet. Risken finns att deformationerna gör så arbetsmaterialet flyttas och det kan påverka positionen för bockningen.Målet med studien var att mäta laster och deformationer i kantviksmaskinen och sammanställa mätdata för att jämföra med FEM-analyser av konstruktionen och till grund för framtida arbete med maskinen. Problemet undersöktes genom att utföra mätningar med LVDT-givare och en lastcell. Mätresultatet visade att det blev en förskjutning och vid fastklämningen av arbetsmaterialet varierade klämkraften. FEM-analyserna kom upp i en lägre förskjutning än den uppmätta. Det finns då misstanke om att en del av förskjutningen kan bero på en mekanism för verktygsbyte. För att bekräfta detta behöver mätningar genomföras som kan visa bidraget av deformation från denna mekanism. FEM-analyserna gjordes med olika lastfördelning för att motsvara klämkraften. Analysen med en uppdelad last var baserad på klämkraftens fördelning som var uppmätt och det gav en fördelning av förskjutningen som var lik den uppmätta. För framtida analyser rekommenderas att använda denna eller en liknande lastfördelning. Utifrån mätningar och analyser konstateras det att överprismat böjs och vrids under klämningen. Detta i sin tur ändrar öververktygens position samt bidrar till att klämning inte sker i mittenpositionerna. / In an edge folding machine, used for sheet metal bending, which have undesired deformations in the mechanism that clamps the work material there is a risk that the deformations will cause the work material to be moved and this can affect the position of the bending. The aim of the study was to measure loads and deformations in the edge folding machine and compile measurement data to compare with FEM-analyzes of the design to get a basis for future work with the machine. The problem was investigated by carrying out measurements with LVDT-sensors and a load cell. The results showed that there was a displacement in the clamping of the work material and that the clamping force varied. The FEM-analyzes came up in a lower displacement than the measured one. A possible conjecture could be that a part of the displacement may be due to the tool change mechanism. To confirm this, measurements need to be performed which can show the contribution of deformation from this mechanism. The FEM-analyzes were made with different load distribution to correspond to the clamping force. The analysis with a divided load where the sectioning was based on the distribution of the clamping force that was measured gave a distribution of the displacement that was similar to the measured. For future analyzes it is recommended to use this or a similar load distribution. Based on measurements and analyzes it is found that the upper prism is bent and twisted during the clamping. This changes the position of the top tools and contribute to no clamping in the middle positions.

As is generally known, pressure-resistant solenoids for valves are used in hydraulics and pneumatics. These solenoids, for example, consist of a so-called pole tube with an integrated armature and a separate solenoid coil. Suitable displacement measuring systems are used in order to measure the armature´s as well as valve spool´s position constnatly; these ar directly mounted to the solenoid. Exeamples here are Hall Effect sensors or LVDT transducers. In case of lesser requirements, it is also possible to measure the valve spool´s position directly and in simplified manner. Here, partially standard proximity sensors are employed, which use the valve spool directly as measuring object. In these cases, however, only discrete position measurement is possible. A constant displacement measurement is not necessary. By means of the sensorless position-control developed by MSM, the armature´s position can be executed directly by analyzing the solenoid coil, partly replacing the usual sensors, under adapted basic conditions.

The diploma thesis aim to the design of equipment for ŠKODA JS a.s., which is part of a new inspection stand (N-SIO). This equipment is an inspection column that provides the possibility to inspect spent fuel assemblies at the operation of the Temelín nuclear power plant. This master thesis is also a summary of the whole design of the new inspection stand and a description of the individual inspection components and devices. One of the parts of the thesis is also a basic strength analysis and a drawing of the main assembly of inspection equipment.

This thesis work deals with the volume changes during the solidification of cast irons and peritectic steels. The volume changes in casting metals are related to the expansion and/or contraction of the molten metal during solidification. Often, different types of shrinkage, namely macro- and micro-shrinkage, affect the casting quality. In addition to that, exposure of the metal casting to higher contraction or expansion during the solidification might also be related to internal strain development in samples, which eventually leads to surface crack propagation in some types of steel alloys during continuous casting. In consequence, a deep understanding of the mechanisms and control of the solidification will improve casting quality and production. All of the experiments during the entire work were carried out on laboratory scale samples. Displacement changes during solidification were measured with the help of a Linear Variable Displacement Transformer (LVDT). All of the LVDT experiments were performed on samples inside a sand mould. Simultaneously, the cooling curves of the respective samples during solidification were recorded with a thermocouple. By combining the displacement and cooling curves, the volume changes was evaluated and later used to explain the influence of inoculants, carbon and cooling rates on volume shrinkages of the casting. Hypoeutectic grey cast iron (GCI) and nodular cast iron (NCI) with hypo-, hyper- and eutectic carbon compositions were considered in the experiments from cast iron group. High nickel alloy steel (Sandvik Sanbar 64) was also used from peritectic steel type. These materials were melted inside an induction furnace and treated with different types of inoculants before and during pouring in order to modify the composition. Samples that were taken from the LVDT experiments were investigated using a number of different  methods in order to support the observations from the displacement measurements:  Differential Thermal Analysis (DTA), to evaluate the different phase present; Dilatometry, to see the effect of cooling rates on contraction for the various types of alloys; metallographic studies with optical microscopy; Backscattered electrons (BSE) analysis on SEM S-3700N, to investigate the different types of oxide and sulphide nuclei; and bulk density measurements  by applying Archimedes' principle. Furthermore, the experimental volume expansion during solidification was compared with the theoretically calculated values for GCI and NCI. It was found that the casting shows hardly any shrinkage during early solidification in GCI, but in the eutectic region the casting expands until the end of solidification. The measured and the calculated volume changes are close to one another, but the former shows more expansion. The addition of MBZCAS (Si, Ca, Zr, Ba, Mn and Al) promotes more flake graphite, and ASSC (Si, Ca, Sr and Al) does not increase the number of eutectic cells by much. In addition to that, it lowers the primary austenite fraction, promotes more eutectic growth and decreases undercooled graphite and secondary dendritic arm spacing (SDAS). As a result, the volume expansion changes in the eutectic region. The expansion during the eutectic growth increase with an increase in the inoculant weight percentage. At the same time, the eutectic cells become smaller and increase in number. The effect of the inoculant and the superheat temperature shows a variation in the degree of expansion/contraction and the cooling rates for the experiments. Effective inoculation tends to homogenize the eutectic structure, reducing the undercooled and interdendritic graphite throughout the structure. In NCI experiments, it was found that the samples showed no expansion in the transversal direction due to higher micro-shrinkages in the centre, whereas in the longitudinal direction the samples shows expansion until solidification was complete.   The theoretical and measured volume changes agreed with each other. The austenite fraction and number of micro-shrinkage pores decreased with increase in carbon content. The nodule count and distribution changes with carbon content. The thermal contraction of NCI is not influenced by the variation in carbon content at lower cooling rates. The structural analysis and solidification simulation results for NCI show that the nodule size and count distribution along the cross-sections at various locations are different due to the variation in cooling rates and carbon concentration. Finer nodule graphite appears in the thinner sections and close to the mold walls. A coarser structure is distributed mostly in the last solidified location. The simulation result indicates that finer nodules are associated with higher cooling rate and a lower degree of microsegregation, whereas the coarser nodules are related to lower cooling rate and a higher degree of microsegregation. As a result, this structural variation influences the micro-shrinkage in different parts. The displacement change measurements show that the peritectic steel expands and/or contracts during the solidification. The primary austenite precipitation during the solidification in the metastable region is accompanied by gradual expansion on the casting sides. Primary δ-ferrite precipitation under stable phase diagram is complemented by a severe contraction during solidification. The microstructural analysis reveals that the only difference between the samples is grain refinement with Ti addition. Moreover, the severe contraction in solidification region might be the source for the crack formation due to strain development, and further theoretical analysis is required in the future to verify this observation. / <p>QC 20170228</p>

Se ha estudiado el efecto de las restricciones hídricas en distintos períodos fenológicos, y de la carga de cosecha sobre la respuesta agronómica y las relaciones hídricas de una plantación joven de ciruelo Japonés cv. Black-Gold. En post-cosecha, las restricciones hídricas permitieron ahorros de agua de hasta un 29% sin afectar ni a la intensidad de floración ni el cuajado ni el crecimiento del fruto del año siguiente. Sin embargo, a medio plazo, tres años, el estrés hídrico aplicado en post-cosecha puede reducir la produción de la plantación debido al efecto acumulado de las restricciones sobre el crecimiento del árbol. El estrés hídrico llevado a cabo durante las fases II y toda la fase III del crecimiento del fruto, redujo su tamaño de forma proporcional a la integral de estrés. La restricción moderada del riego, antes y después de la cosecha, auanque permitió el mayor ahorro de agua (30%), provocó una reducción demasiado severa en el crecimiento del árbol, además de afectar al crecimiento del fruto. La carga alta de cosecha redujo el tamaño final del fruto en un 16%, pero permitió aumentar la cosecha en un 46% además de afectar al crecimiento vegetativo del árbol. La carga también afectó a las relaciones hídricas del árbol. Por otra parte se ha demostrado la eficacia de los dendómetros y del potencial de hoja no transpirante como indicadores de estrés hídrico. Finalmente se evaluó la utilidad de los sensores Watermark que respondieron razonablemente bien a las restricciones del riego, en particular cuando fueron severas, y permiten estimar con cierta precisión el estado hídrico del árbol, en particular para Ym<-40kPa. / Intrigliolo Molina, DS. (2005). Efectos del riego deficitario y de la carga de cosecha sobre las relaciones híbricas y la respuesta agronómica del ciruelo japonés cv. Black-Gold [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1869 / Palancia

Ultraprecision single point diamond turning is required to produce parts with sub-nanometer surface roughness and sub-micrometer surface profiles tolerances. These parts have applications in the optics industry, where tight form accuracy is required while achieving high surface finish quality. Generally, parts can be polished to achieve the desired finish, but then the form accuracy can easily be lost in the process rendering the part unusable. Currently, most mid to low spatial frequency surface finish errors are inspected offline. This is done by physically removing the workpiece from the machining fixture and mounting the part in a laser interferometer. This action introduces errors in itself through minute differences in the support conditions of the over constrained part on a machine as compared to the mounting conditions used for part measurement. Once removed, the fixture induced stresses and the part’s internal residual stresses relax and change the shape of the generally thin parts machined in these applications. Thereby, the offline inspection provides an erroneous description of the performance of the machine. This research explores the use of a single, high resolution, capacitance sensor to quickly and qualitatively measure the low to mid spatial frequencies on the workpiece surface, while it is mounted in a fixture on a standard ultraprecision single point diamond turning machine after a standard facing operation. Following initial testing, a strong qualitative correlation exists between the surface profiling on a standard offline system and this online measuring system. Despite environmental effects and the effects of the machine on the measurement system, the capacitive system with some modifications and awareness of its measurement method is a viable option for measuring mid to low spatial frequencies on a workpiece surface mounted on an ultraprecision machine with a resolution of 1nm with an error band of ±5nm with a 20kHz bandwidth. / Thesis / Master of Applied Science (MASc)