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Within the era of the fourth industrial revolution the steel production industry is faced with demands of lower environmental impact and more cost-effective production are some of the challenges faced. To achieve more sustainable and efficient manufacturing processes companies try to digitalize and automate their production to a greater extent. Creating more robust, energy-efficient and adaptable solutions to increase the competitiveness of their company. This master thesis is about reverse engineering an existing solution for vibration measurements used at Alleima Strip. The goal was to create a new in-house solution for vibration measurements according to local programming standards using an ABB AC500v2 CPU paired with a FM502-CMS module. Using vibration measurements as a health indicator Alleima Strip hopes to progress their way of working with maintenance towards being more condition based. The result is a solution for vibration measurements customized for Alleima Strip. The report contains suggestions for improvements of the developed solution as well as ideas for future work.

This thesis deals with the measurement and evaluation of vibration on selected parts of car. Part of the work is devoted to the theory of vibration and noise, which includes, among others, presentations of common disorders of machine parts in terms of vibration. In the practical part of the work were performed out measurements described here and the results analyzed. Last part is in short devoted to the possibilities of using a similar measurement in forensic engineering.

During strong earthquakes structural systems exhibit nonlinear behavior due to low-cycle fatigue, cracking, yielding and/or fracture of constituent elements. After a seismic event it is essential to assess the state of damage of structures and determine if they can safely resist aftershocks or future strong motions. The current practice in post-earthquake damage assessment relies mainly on visual inspections and local testing. These approaches are limited to the ability of inspectors to reach all potentially damaged locations, and are typically intended to detect damage near the outer surfaces of the structure leaving the possibility of hidden undetected damage. Some structures in seismic prone-regions are instrumented with an array of sensors that measure their acceleration at different locations. We operate under the premise that acceleration response measurements contain information about the state of damage of structures, and it is of interest to extract this information and use it in post-earthquake damage assessment and decision making strategies. The objective of this dissertation is to show that Bayesian filters can be successfully employed to estimate the nonlinear dynamic response of instrumented structural systems. The estimated response is subsequently used for structural damage diagnosis. Bayesian filters combine dynamic response measurements at limited spatial locations with a nonlinear dynamic model to estimate the response of stochastic dynamical systems at the model degrees-of-freedom. The application of five filters is investigated: the extended, unscented and ensemble Kalman filters, the particle filter and the model-based observer. The main contributions of this dissertation are summarized as follows: i) Development of a filtering-based mechanistic damage assessment framework; ii) Experimental validation of Bayesian filters in small and large-scale structures; iii) Uncertainty quantification and propagation of response and damage estimates computed using Bayesian filters.

Magistro baigiamojo darbo teorinėje dalyje analizuojami įvairūs virpesių lygio mažinimo būdai bei schemos laivuose. Aprašoma virpesių klasifikacija, pagrindiniai virpesių žadintojai laive, virpesių skaičiavimo būdai. Eksperimentinėje dalyje pateikiama kelto „Optima Seaways“ siurblio virpesių matavimo metodika. Nagrinėjami reiso Klaipėda-Karlshamnas-Klaipėda metu atliktų matavimų rezultatai bei nustatomos tiriamo siurblio padidinto virpesių lygio priežastys. Paskutinėje darbo dalyje pateikiamas racionalus sprendimas, reikalaujantis minimalių lėšų ir laiko sanaudų, tiriamo siurblio virpesių lygio sumažinimui. / The theoretical part of the Master’s thesis analyzes various vibration reduction systems and schemes in ships. Classification of vibrations on board, main vibration sources and vibration calculations are presented. The experimental part presents methodic for vibration measuring of ferry “Optima Seaways” pump. Vibration data, received during passage Klaipėda- Karlshamn- Klaipėda, is analyzed and reason of high pump vibration level is identified. Last part of thesis presents rational solution, with minimal cost and time expenses, for reduction of pump vibration level.

High quality noise and vibration measurements outside of a laboratory environment on real life structures and applications are not trivial. True boundary and operating conditions enforce unique challenges on the measurements. Measurements in hazardous situations such as high magnetic fields, and high temperature environments, etc., where ordinary measurement equipment and methods may not be employed, require further precautions. Post measurements objectives such as analysis, design and strategic decisions, e.g., control, rely heavily on the quality and integrity of the measurements (data). The quality of the experimental data is highly correlated with the on-field expertise. Practical or hands-on experience with measurements can be imparted to prospective students, researchers and technicians in the form of laboratory experiments involving real equipment and practical applications. However, achieving expertise in the field of sound and vibration measurements in general and their active control in particular is a time consuming and expensive process. Consequently most institutions can only afford a single setup, resulting in the compromise of the quality of expertise. In this thesis, the challenges in the field of sound and vibration measurements in high magnetic field are addressed. The analysis and measurement of vibration transferred from an operational magnetic resonance imaging (MRI) scanner to adjacent floors is taken as an example. Improvised experimental measurement methods and custom-made frequency analysis techniques are proposed in order to address the challenges and study the vibration transfer. The methods may be extended to other operational industrial machinery and hazardous environments. To encourage and develop expertise in the field of acoustic/vibration measurements and active noise control on practical test beds, remotely controlled laboratory setups are introduced. The developed laboratory setup, which is accessed and controlled via the Internet, is the first of its kind in the active noise control and acoustic measurements area. The laboratory setup can be shared and utilized 24/7 globally, thus reducing the associated costs and eliminating time restrictions.

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In this study, data on vibration measurements from Forsmark - Vattenfall AB's database has been studied, the goal has been to see how it can be reworked so that it becomes easier to interpret and more transparent for more people in maintenance.The idea has been to use all the data available to create graphs or graphs over a longer period to look for trends in systems that are similar to each other. Which is because there is redundancy in the systems and blocks 1 & 2 are sibling blocks with identical components, so it is possible to compare them.Furthermore, it is intended to implement the results from this work in balanced scorecards that are already used at Forsmark at present. This is done to obtain data on how the maintenance is going and how many machines need to be maintained compared to previous periods.The work has consisted of retrieving data files from Forsmark's database and via an Excel script that reworks all data so that graphs can be created of the various measurements performed regularly by the Maintenance Group NMM 1-3 (Mechanical Maintenance) at Forsmark.The results of the work have been verified through the special software that NMM 1–3 uses but in which other groups have no experience. In this special software all graphs and data are already available, something that is not as easy, however, is the ability to compare different machines at the same time, something that this thesis work tries to create.As others in maintenance do not have experience in the specialized software, Excel is used instead, as it is a program all groups have access to and good knowledge in. What emerges from the work is that the amount of data is very large but the possibility to get to the goal is good, the data files need some reworking to be easily used for graph creation and some things are unfortunately not included in the data files but must be downloaded from the special software NMM 1- 3 have. / I denna studie har data över vibrationsmätningar från Forsmark – Vattenfall AB:s databas studerats, målet har varit att se hur den ska kunna omarbetas så att den blir lättare att tolka och mer överskådlig för flera inom underhåll.Idén har varit att använda all den data som finns tillgänglig för att skapa graf eller grafer över längre tid för att leta efter trender inom system som är snarlika varandra, vilket finns eftersom det finns redundans i systemen och block 1 & 2 är syskonblock, så det går att jämföra mellan dem.Vidare är det tänkt att implementera resultatet från detta arbete i balanserade styrkort (Scorecard) som redan används på Forsmark i dagsläget, detta görs för att få in data över hur underhållet går och hur många maskiner som behöver underhållas jämfört med tidigare perioder.Arbetet har gått ut på att hämta datafiler från Forsmarks databas och via ett Excel script som omarbetar all data så att grafer kan skapas över de olika mätningar som utförs regelbundet av Underhållsgruppen NMM 1–3 (Mekaniskt underhåll) på Forsmark.Arbetets resultat har verifierats genom den speciella programvara som NMM 1–3 använder men som övriga grupper inte har erfarenhet av. Där finns alla grafer och all data redan att tillgå, något som inte finns lika enkelt är dock möjligheten att jämföra olika maskiner samtidigt, något som detta arbete försöker skapa.Då övriga inom underhåll inte har erfarenhet inom den programvaran så används Excel i stället, då det är ett program alla har tillgång till och god kunskap inom. Det som framkommer av arbetet är att mängden data är väldigt stor men möjligheten att komma till målet är goda, datafilerna behöver viss omarbetning för att enkelt kunna användas för graf skapande och vissa saker finns tyvärr inte med i datafilerna utan måste hämtas från specialprogramvaran NMM 1–3 har.

Ce travail de recherche a été mené afin d'introduire une nouvelle classe de résonateurs Fabry-Pérot (FP) : les cavités FP incurvées basées sur des miroirs de Bragg sans revêtement, de forme cylindrique sont obtenues par micro-usinage du silicium. Une autre spécificité est la longueur de la cavité relativement grande (L> 200 µm) combinée à un haut facteur de qualité Q (jusqu'à 10^4 ), pour répondre aux applications de type spectroscopie d'absorption améliorée par résonance optique, dans lesquelles le produit Q.L est une figure de mérite. Dans ce contexte, l'architecture de base a été modélisée analytiquement pour déterminer les modes transverses d'ordre élevé supportés par de telles cavités. Par conséquent, les conditions expérimentales qui conduisent à une excitation préférentielle (ou rejet) de ces modes ont été testées menant à la validation de notre modèle théorique et à une meilleure compréhension du comportement de la cavité. Une seconde architecture,basée sur la cavité FP incurvée avec une lentille cylindrique a été développée dans le but de fournir une architecture plus stable. Cette dernière a été également modélisée, fabriquée et caractérisée, menant à l'amélioration attendue en termes de performances. D'un autre côté, un point surlignant l'une des applications potentielles que nous avons identifiées pour les cavités incurvées est présentée en insérant la cavité dans un système électromécanique. Ceci consiste à exciter et mesurer les vibrations d'amplitude nanométrique par couplage opto-mécanique dans un résonateur mécanique MEMS intégrant une cavité optique FP. Enfin, comme complément à notre étude sur les résonateurs, nous avons commencé à explorer les applications des interféromètres optiques à base de miroirs de Bragg en silicium. À cette fin, un microsystème de mesure optique a été conçu, fabriqué et caractérisé, il consiste en une sonde optique pour la profilométrie de surface dans des milieux confinés, basé sur un interféromètre de Michelson monolithique en silicium / This research work has been conducted to introduce a novel class of Fabry-Perot (FP) resonators : curved FP cavity based on coating-free Bragg mirrors of cylindrical shape, obtained by silicon micromachining. Another specificity is the rather large cavity lengths (L>200 µm) combined with high quality factor Q (up to 104), for the purpose of applications requiring cavity enhanced absorption spectroscopy, in which the product Q.L is a figure of merit. In this contest, the basic architecture has been modeled analytically to know the high order transverse modes supported by such cavities. Hence, the experimental conditions which lead to preferential excitation (or rejection) of these modes have been tested experimentally leading to the validation of our theoretical model and to a better understanding of the cavity behaviour. A second architecture, based on the curved FP together with a fiber rod lens has been developed for the purpose of providing stable designs. It was also modeled, fabricated and characterized leading to the expected performance improvements. On another side, a highlight on one of the potential applications that we identified for the curved cavities is presented by inserting the cavity into an electro-mechanical system. It consists of exciting and measuring tiny vibration through opto-mechanical coupling in a MEMS mechanical resonator embedding an FP cavity.Finally, as a complement to our study on resonators, we started exploring applications of optical interferometers based on similar micromachined silicon Bragg mirrors. For this purpose, an optical measurement microsystem was designed, fabricated and characterized ; it consists of an optical probe for surface profilometry in confined environments, based on an all-silicon Michelson interferometer

This research work has been conducted to introduce a novel class of Fabry-Perot (FP) resonators : curved FP cavity based on coating-free Bragg mirrors of cylindrical shape, obtained by silicon micromachining. Another specificity is the rather large cavity lengths (L>200 µm) combined with high quality factor Q (up to 104), for the purpose of applications requiring cavity enhanced absorption spectroscopy, in which the product Q.L is a figure of merit. In this contest, the basic architecture has been modeled analytically to know the high order transverse modes supported by such cavities. Hence, the experimental conditions which lead to preferential excitation (or rejection) of these modes have been tested experimentally leading to the validation of our theoretical model and to a better understanding of the cavity behaviour. A second architecture, based on the curved FP together with a fiber rod lens has been developed for the purpose of providing stable designs. It was also modeled, fabricated and characterized leading to the expected performance improvements. On another side, a highlight on one of the potential applications that we identified for the curved cavities is presented by inserting the cavity into an electro-mechanical system. It consists of exciting and measuring tiny vibration through opto-mechanical coupling in a MEMS mechanical resonator embedding an FP cavity.Finally, as a complement to our study on resonators, we started exploring applications of optical interferometers based on similar micromachined silicon Bragg mirrors. For this purpose, an optical measurement microsystem was designed, fabricated and characterized ; it consists of an optical probe for surface profilometry in confined environments, based on an all-silicon Michelson interferometer