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This work was initiated in order to show the potential for Swedish sawmills to achieve higher productivity by implementation of improved process control tools in breakdown and production flows. Accessible and reliable production data are crucial information concerning the area of process control; hence the objective in this study was to create a "toolbox" of suitable tools for decision support, surveys and analyses. Modern sawmills are becoming increasingly like process industries. Process control and optimization tools in sawmills have, however, not followed the rapid development of automation and increased production speed. Each machine, monitoring system or data system is commonly viewed as a detached system rather than as part of the same process. This fact makes it difficult to access process data and monitor the performance of a sawmill and, further, to address problems at the sawmill. Hence there is an identified need to introduce and use effective methods of collecting and connecting information, analysis and evaluation, as well as methods for rapid linking of results and measures that have been decided on back to the production line. Reliable and relevant information is also vital to creating a measure of confidence that changes are indeed implemented based on facts, not merely on assumptions or prior experiences. Thus, reliable systems for collecting process data and benchmarking methods such as Overall Equipment Effectiveness must be implemented. A mobile diagnostic monitoring and analysis tool developed during the study enables detailed and simplified registration of downtime and error causes in the sawmill. An increased and optimized usage of a suitable "tool package" including benchmarking methods, simulation software and process monitoring and analysis tools creates a solid base for implementation of process control and for increased productivity. An effective and profitable sawmill must utilize its raw material and the skill of its staff effectively. Sawmill production could usefully adopt appropriate areas of process thinking and optimizing methods from the mechanical process industry. Results achieved during surveys and simulations reveal a large potential to improve equipment availability and effectiveness on the sawline. Breakdown simulations show a potential to improve volume yield by improving sorting capability and, furthermore, by handling logs as single individuals during the breakdown procedure rather than as parts in a batch. Optimal volume yield can be achieved from every log by applying optimal sawing pattern, log rotation and offsets in first and second saw. / Moderna sågverk liknar alltmer en processindustri. Mycket stora värden flödar genom processen varje sekund. Tyvärr har inte utvecklingen av processkontroll och processtyrning inom sågverken följt med i sågverkens utveckling mot en processindustri. I ett modernt sågverk genereras enorma mängder av data som utnyttjas för att styra processen men det saknas också på de flesta sågverken en mängd data för att kunna genomföra en fullständig processtyrning. På många sågverk görs ingen kontinuerlig kontroll av processparametrar som måttnoggrannhet, felinläggning, utbyte på sågklassnivå, matningshastighet, fliskvalitet, hanteringsskador, driftstoppsfrekvens och driftstoppsorsak (alla driftstopp, även korta). Vad som definitivt saknas på de allra flesta sågverk är metoder för sammankoppling av information, utvärdering, analys och återkoppling till processen. Problemet är att man ser varje bearbetningsmaskin, mätsystem eller databehandlingssystem som fristående system i stället för en del av en process. Lundahl har i sitt arbete använt sönderdelnings- och flödessimuleringsmodeller för att analysera sågverksprocessen. Som ett sammanhållande kitt mellan dessa modeller har konceptet "Overall Equipment Efficiency" (OEE) använts. Styrkan med OEE-konceptet är att man samtidigt kan ta hänsyn till processens kapacitet och till dess kvalitet. Under arbetets gång visade det sig att värdsågverkens data beträffande stopptider var för bristfälliga för att kunna erhålla en valid flödesmodell. Som en del av projektet har därför ett datainsamlingsverktyg utvecklats. Lundahls arbete visar att moderna sönderdelnings- och flödesmodeller har en stor potential för analys och optimering av sågverksprocessen. I det flesta fall krävs dock att kvaliteten hos processinformationen förbättras. Det datainsamlingsverktyg som utvecklats inom ramen för projektet ger härvidlag möjligheter till väsentligt förbättrad informationskvalitet. / <p>Godkänd; 2007; 20070126 (ysko)</p>

Earlier measurements on hydropower generators have indicated the existence of backward whirling motion, and, also relatively large shape deviations in both the rotor and the stator. These non-symmetric geometries produce an attraction force between the rotor and the stator, called unbalanced magnetic pull (UMP). The target of this thesis is to analyse the dynamic consequences of shape deviations in hydropower generators. A mathematical model is developed to describe the shapes of the rotor and stator, and the corresponding UMP is obtained through the law of energy conservation. Theorems about the existence of stable equilibria and whirling motion of the rotor response are proved mathematically for certain cases. The results indicate that different whirling motions, including both backward and forward whirling can occur. Generator dynamics are further investigated by simulating the basin of attraction, giving a measure of the robustness of the attractors. From this, the magnitudes are approximately obtained when the shape deviations become dangerous for the generator. It is concluded which shape deviations that are more dangerous than others. In hydropower generator maintenance the shapes of the rotor and stator are frequently measured. The results from this thesis can be used to evaluate such measurements and explain the existence of complicated whirling motion. / <p>Godkänd; 2006; 20070109 (haneit)</p>

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Alvsbacka Bridge was erected in the summer of 2011. During the planningof the construction researchers from LTU and SP Tr¨a designed ahealth monitoring system that constantly measures different parameterson the bridge. The motivation for health monitoring systems is several:Bridge safety, verification of the design and complement during inspections.Health monitoring of infrastructure is common, many bridges areequipped with health monitoring systems. Timber bridges are rarely monitored.This research project is looking to answer what type of sensorsis suitable for bridges in order to make them smart. The smartness ofthe bridge in this case is to help optimize bridge maintenance, assurethe service life and build knowledge about measurements on large timberconstructions. This thesis presents the monitoring system of the bridge,moisture content monitoring and studies the weather effects on the bridge.The monitoring system of ¨Alvsbacka Bridge consists of several differentsensor systems that continuously measure temperature, moisture content,movements, cable forces, wind velocity, wind direction. The monitoringsystem had some problems with sensors not communicating. Long termmoisture content monitoring show anticipated results and the bridge deckmovements are close to the theoretical values. / Godkänd; 2015; 20150126 (nicbjo)

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It is implied that Functional Products fundamentally change how the product development process is performed in global settings. An extended product definition together with the need to evaluate product properties earlier creates new demands on engineering methods and tools needed during the product development process. A trend is for the customer to want to buy extended solutions provided by many companies in a network. The companies are then forced to cooperate as early as possible in the product development phase to minimize the business risks. Functional products increase the amount of design parameters considered in the conceptual phase. Hardware, manufacturing, service and business parameters are all essential. However, there is a lack of methods to vary the extended set of design parameters in the conceptual design stage. The aerospace industry as well as other manufacturing companies with an increased product complexity develops their offers together globally, meaning that a design parameter can be distributed between several partners. Changing a parameter forces each partner to perform the necessary activities and share the result to gather the overall view. Inserting the functional product perspective into the aerospace industry creates totally new demands on the product development process with a life cycle perspective. Design parameters not normally involved in the early phases should now be considered. The purpose of this research is to develop a method that can enable this extended set of design parameters to be evaluated and manipulated in the early stages of product development. The research strategy is to combine participatory action research process with a case study approach and to verify the approach close to technology and product development activities in industries. The research approach is to combine KBE, CAD and CAE technologies to create a more generative product model, which can automate activities in the conceptual phase of the product development process. Using a generative technical product model that adapts different design parameter settings extends the set of product properties to be evaluated. The generative model can also be used globally and distributed, enabling the evaluation of an extended set of design parameters in a global and distributed conceptual phase. With an increased ability to generate different models more product life cycle properties can be simulated and increase the conceptual information basis. This improves the ability to address product life cycle properties for functional product offers already in the conceptual phase. / Godkänd; 2007; 20070504 (ysko) / Functional Jet Engine Components - NFFP

Wood is a biological material with inherent aesthetic properties which can give the final product a competitive advantage over other materials. In this thesis, people’s feelings and preferences for Scots pine (Pinus sylvestris) wood surfaces have been examined. The main objectives of this thesis are to develop methods for measuring people’s preferences toward different looks of wood and to connect the subjective preference data with objective measurements of wood features. It comprises both qualitative and quantitative methods for collecting preference data. Two projection methods, PCA and PLS, were used to analyze the quantitative studies. Interviews made clear that people prefer different blends of wood features. There are two qualitative differences that are of importance for people's impressions and valuations of wood: The overall blend of wood features and divergent features that mismatch in a surface. It was found that divergent features are more important than the overall mixture of features. But if there are no defects that mismatch, the overall mixture will then be the key to a person's appreciation of a wood surface. Wood surfaces should stimulate people's interest and be fresh looking. A clear surface is naturally rather harmonious, elegant and easy to look at. On the other hand, a clear surface should be stimulating to look at, should be exciting and it should not look like an imitation. Knotty surfaces usually are less harmonious. Therefore, questions about harmony, easiness to look at and balance are of importance. Just as for clear surfaces, a knotty surface should also stimulate people's interest, have a fresh look, be exciting and stimulating to look at. The quantitative studies show that it is possible to measure people’s preferences toward wood by a questionnaire technique. The results also show that there are differences in people’s judgments for surfaces with knots and for those without knots. There are stronger connections between questions regarding the overall impression and the final assessment than there are for detailed questions regarding certain wood features. Thirteen questions were pointed out as relevant to use with interviews. Two interview methods were compared. The first method used wood surfaces and the second used computer images with the same wood surfaces applied to an example product, a kitchen cabinet. The results show that the two methods are comparable and useful. It was shown that it is possible to some extent to connect subjective preference data with objective wood feature measurements. Results show that a lot of wood feature measurements are needed and that it is a multivariate problem. Concerning the measurements, it seems easier to find features that negatively affect people’s liking than to find the opposite. Among the most important variables were those that detect different kinds of feature distribution over a wood surface, and especially those variables that detect a deviation in center of gravity. Increased knowledge about people’s preferences for the aesthetic properties of wood will lead to a better understanding of which wood features should be measured and controlled in the future. / Godkänd; 2000; 20061116 (haneit)

For many decades, humans have been consuming more resources than the world has to offer in the long run. Increasing the use of renewable materials, such as wood, is essential if we are to achieve a sustainable use of the resources available to us. Densification of wood in general, and surface densification in particular, has the potential to improve the properties of widely available low-density wood species, opening up new fields of application, and fostering the use of wood products in general. The objective of this thesis is to put past research within the field of surface densification of solid wood and advancements within the present project into a context, and to suggest a path towards a performance-driven and cost-effective type of product. A prevalent research gap has been identified and this thesis summarizes how this gap can be filled by already conducted and future studies. Important aspects that need be handled in order to fulfill the overall vision of the large-scale commercialization of surface-densified wood products are considered. Past studies were successful in gaining a good understanding of different approaches to the densification of solid wood, such as using a hot press or a friction welding machine. Problems, such as the moisture-induced recovery of the densified wood cells could be solved from a technological perspective. However, those studies did not take into account industrial implementation. Existing methods are time- and/or energy-consuming. The use of roller-pressing equipment showed promising results, but also highlighted certain limitations. Solid wooden boards have been successfully surface-densified at speeds of up to 80 m/min. However, problems arose regarding the plasticization and stabilization of the densified wood cells, indicating that a continuous belt-press approach might be more viable with regard to the objective of industrial implementation. In parallel, a structured method to identify the most suitable wood species for surface densification has been presented, with the aim of propagating the use of surface-densified wood products and widening their fields of application. This method has confirmed the suitability of previously used wood species, and has also suggested alternatives not considered thus far. Previous studies into the surface densification of wood have provided a rather sound understanding of the densification process and have provided a useful foundation for the current project. The work done, thus far, has shown the viability of a continuous densification process and has indicated a sensible path towards the widespread establishment of surface-densified wood products on the market.

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