Leimuhitsauksen kokonaisvaltainen laadunhallinta päättymättömässä valssauksessa

Leimuhitsauksen laadunhallinnassa tärkeää on prosessimainen toiminta ja toimintojen kokonaisvaltaisuuden hahmottaminen. Leimuhitsauksen ollessa osana päättymätöntä valssausta hitsauksen laadunhallinta voidaan jakaa kolmeen päävaiheeseen: ennen hitsausta, hitsauksen aikana ja hitsauksen jälkeen vaikuttaviin laaduntuottotekijöihin. Leimuhitsauksen laaduntuottotekijöiden määritys ja jaottelu kaavioiksi on toteutettu tässä työssä. Leimuhitsin tekniseen laatuun vaikuttavat monet ilmiöt ja parametrit hitsauksen aikana. Tärkeimpiä hitsausparametreista ovat hitsausjännite, alustan liikenopeus, tyssäysmatka sekä leimutusaika. Väärät hitsausolosuhteet tai hitsausparametrit aiheuttavat erilaisia mekaanisia ja metallurgisia vikoja leimuhitsiin. Eräs metallurginen vikatyyppi ovat oksidisulkeumat hitsialueella. Nämä hapettuneet alueet voivat johtaa juurensa erilaisista syistä ja esimerkiksi leimutusajan ja epätasaisen liitospinnan yhteyttä sulkeumien syntyyn on epäilty. Pidennetyillä leimutusajoilla tehtyjen hitsauskokeiden ja hitsien rikkovien aineenkoetuskokeiden tuloksena todettiin tässä tutkittujen koehitsien oksidisulkeumien syntyvän hapettumalla leimutuksen aikana tai juuri hetkellä ennen tyssäystä, minkä lisäksi kosteat olosuhteet hitsausatmosfäärin ympärillä heikentävät lopputuloksen laatua. Leimutusajalla on tärkein osa leimutettavia pintoja tasaavana tekijänä ja mitä epätasaisempi liitettävä pinta on, sitä pidemmän leimutusajan se tarvitsee.

Control d'una bobinadora automàtica

Un dels problemes típics de regulació en el camp de l’automatització industrial és el control de velocitat lineal d’entrada del fil a les bobines, ja que com més gruix acumulem a igual velocitat de rotació de la bobina s’augmenta notablement la velocitat lineal d’entrada del fil, aquest desajust s’ha de poder compensar de forma automàtica per aconseguir una velocitat d’entrada constant. Aquest problema de regulació de velocitats és molt freqüent i de difícil control a la indústria on intervé el bobinat d’algun tipus de material com cablejat, fil, paper, làmines de planxa, tubs, etc... Els dos reptes i objectius principals són, primer, la regulació de la velocitat de rotació de la bobina per aconseguir una velocitat lineal del fil d’entrada, i segon, mitjançant el guiatge de l’alimentació de fil a la bobina, aconseguir un repartiment uniforme de cada capa de fil. El desenvolupament consisteix amb l’automatització i control d’una bobinadora automàtica mitjançant la configuració i programació de PLC’s, servomotors i encoders. Finalment es farà el muntatge pràctic sobre una bancada per verificar i simular el seu correcte funcionament que ha de donar solució a aquests problemes de regulació de velocitats. Com a conclusions finals s’han aconseguit els objectius i una metodologia per fer una regulació de velocitats de rotació per bobines, amb accionaments de servomotors amb polsos, i a nivell de coneixements he aconseguit dominar les aplicacions d’aquest tipus d’accionaments aplicats a construccions mecàniques.

Lasikuituputkien kelauslinjan automatisointi

Lasikuituputkien kelaamiseen tarkoitettu automaatio voidaan toteuttaa suorakulmaisen kolmion trigonometrian perusteella. Kelaaminen tapahtuu pyörittämällä muottia ja liikuttamalla samalla muottia sivuttain. Näin tehdessä saadaan kelattavat lasikuitulangat leviämään koko muotin leveydelle. Jos langat halutaan saada kelattua tiiviisti toistensa viereen, on muotin liikuttava tietty matka yhtä muotin pyörähdystä kohden. Matkaa kutsutaan nousuksi. Nousu riippuu lankojen muodostaman kimpun leveydestä, kelauskulmasta ja muotin säteestä. Kelauskulmalla voidaan vaikuttaa kelattavan tuotteen aksiaaliseen ja pitkittäiseen lujuuteen. Kelauskoneen automaatiojärjestelmä koostuu sähkökäytöistä, ohjaavasta yksiköstä, valvomosta ja erilaisista antureista. Eri osat yhdistetään toisiinsa väylätekniikalla. Sähkökäytöt ovat yleensä servokäyttöjä, koska niiltä vaaditaan tarkkuutta ja nopeutta. Ohjaavana yksikkönä toimii yleensä teollisuus logiikka. Anturointia tarvitaan esimerkiksi hartsin lämpötilan säätöön ja lankojen ratakireyden säätöön. Anturoinnilla ja säädöillä pyritään parantamaan kelattavan tuotteen laatua. Koneen ohjelmallinen toteutus vaatii kelauskoneen mekaniikan ja kelausprosessin ymmärtämistä. Lisäksi on huomioitava koneen käyttäjät ja heidän turvallisuus.

Rautateiden henkilöliikenteen kehitys Baltian maissa

Työn tavoitteena oli selvittää, millaisia muutoksia Viron, Latvian ja Liettuan rautateiden henkilöliikenteessä on tapahtunut neuvostoajan lopun ja tämän päivän välillä. Tarkastelupisteiksi valittiin vuodet 1991, 1997, 2002 ja 2009. Tutkimuksen tavoitteena oli myös selvittää muutoksiin vaikuttaneita taustatekijöitä, kuvata nykytilannetta ja tarkastella tulevaisuuden vaihtoehtoisia kehityspolkuja. Tutkimuksen tulosten perusteella rautateiden henkilöliikenteen määrä on supistunut noin puoleen kaikissa kolmessa maassa tarkasteltuna junakilometrien viikoittaisella määrällä. Matkustajamäärät ovat laskeneet kaikissa kolmessa maassa selvästi tarkastelujakson aikana. Syitä rautateiden henkilöliikenteen supistumiseen ovat olleet mm. kireä kilpailu linja-autoliikenteen kanssa ja lisääntynyt henkilöautojen käyttö. 1990-luvun taloudellisesti vaikeina vuosina rautateillä ei ollut mahdollisuuksia uusia kalustoaan. Kansainvälinen talouskriisi ja sen myötä heikentynyt taloudellinen tilanne kaikissa kolmessa maassa muodostaa uuden uhan rautateiden henkilöliikenteelle. Korkeat rataverkon käyttömaksut toimivat tehokkaana esteenä henkilöliikenteen kehittämiselle.

Det gyldne snitt : den estetiske dimensjon, en kilde til helse oget etisk anliggende

Within caring science, investigations and explorations have been carried out on the ontology of caring, and many aspects of the field have been the subject of scientific research. The main subject for this study is grounded on the human need for aesthetics. The purpose is to find how the aesthetic dimension is taken into consideration and how the aesthetic surroundings are evaluated and attended to, in the general hospitals in Norway. The theoretical perspective is founded basicly on the study of litterature from caring science and philosophy. The aim is to develop a disposition for a framework on the aesthetic surroundings in the hospitals, and to develop phenomenological and ontological knowledge and understanding of the aesthetic dimension. The study aspires to attain a deeper understanding of the aesthetic acknowledgment and of the aesthetic needs. The focus is how the aesthetic dimension can promote health and wellbeing, both for patients and for the caring staff, in the general hospitals and why the aesthetic dimension should be obligatory in `evident care¿. The study concentrates on 11 selected categories in the hospital environment, where aesthetics is of importance. The research is implemented on 5 part studies: 1. part is a study of caring science and philosophical theories about aesthetics, as a framework for the investigation. 2. part is a survey of the physical environment, in Norwegian somatic hospitals, with focus on aesthetics. This by analyzing the strategy plans for the hospitals. 3. and 4. part is questionnaires to patients and nurses to get their opinion and evaluation of the aesthetic environment in the hospitals they are connected to, and their opinion on how this influences the health and wellness for both patients and caring staff. 5. part is qualitative interviews with 16 experts, to get their opinion and evaluation of the aesthetic environment in hospitals they are or have been connected to. How would the experts like the aesthetic surroundings to be, and also their opinion on what influence they think aesthetics has on health and wellness. The main literature of caring science is rooted in K. Erikssons caring theory as well as philosophic literature; mainly I. Kant, Platon and Y. Hirn's theories on aesthetics. Various scientificresearchers of aesthetics have also been referred to. The methodological approach is a triangulation with a hermeneutic exploration, where H.G. Gadamer and Ricoeur provides the inspirational foundation. The findings and conclusions result in the development of new hypothesis for the caring science foundation and suggestions, a disposition for a framework related to future planning of the aesthetic environments in general hospitals. It might be said that a common thread arises/appears in the invariance's (invariables) that are discerned from the analysis and interpretation of the interviews and also important angles shows in the variances that crystallized. Based on the conclusions the study confirms that there is a clearconnection between health, wellness and aesthetics in the environment and that it is an ethical obligationfor those in the caring professions to be aware of and attend to the aesthetic dimension.

Rullaava ennustaminen talousohjauksen välineenä

Kiinnostus rullaavaa ennustamista kohtaan on kasvanut 2000-luvulla sen tarjotessa vaihtoehdon perinteiselle budjetoinnille. Rullaavasta ennustamisesta ei ole kuitenkaan tehty viimeisimpiin tietoihin perustuvaa tutkielmaa, jossa yhdistetään analyyttisesti uusinta tutkimus- ja kirjallisuustietoa. Tämän lisäksi rullaavaan ennustamiseen liittyvä termistö ei ole vakiintunutta, eikä termistöä ole tutkittu tai vertailtu. Nopeasti muuttuvassa liiketoimintaympäristössä perinteinen budjetointi ei enää vastaa siihen tarpeeseen, mihin se on tarkoitettu. Kritiikki budjetointia kohtaan on kasvanut mutta edelleen suurin osa yrityksistä käyttää sitä talousohjauksessa. Perinteinen budjetointi koetaan kalliiksi, aikaa vieväksi sekä irralliseksi strategiasta. Lisäksi se ei ota huomioon muuttuvaa ympäristöä ja on usein vanhentunut jo käyttöönotettaessa. Näitä budjetoinnin heikkouksia voidaan poistaa ottamalla käyttöön rullaava ennustaminen talousohjauksen välineenä. Rullaavassa ennustamisessa on kyse siirtymisestä kiinteästä budjettivuodesta esimerkiksi neljännesvuosittain ylemmällä tasolla tapahtuvaan ennustamiseen ennusteajanjakson ulottuessa aina seuraavalle vuodelle. Rullaavaa ennustamista voidaan käyttää budjetoinnin ohella, mikä on tutkimusten mukaan selvästi suosituin menetelmä. Toinen vaihtoehto on korvata perinteinen budjetointi rullaavalla ennustamisella. Tällöin prosessia kutsutaan rullaavaksi budjetoinniksi tai suunnitteluksi. Kolmas vaihtoehto on budjetoinnin hylkääminen ja uusien taloudenohjauksen ja prosessien soveltaminen eli Beyond Budgeting. Tämä korostaa budjetoinnin hylkäämisen lisäksi suorituskyvyn mittaamista ja palkitsemista suhteellisiin tuloksiin ja ulkoiseen sekä sisäiseen vertailuun perustuen sekä vallan hajauttamista organisaatiossa tavoitteena asiakasarvon kasvattaminen.

High-speed solid-rotor induction machine – calculation program

The aim of this thesis is to utilize the technology developed at LUT and to provide an easy tool for high-speed solid-rotor induction machine preliminary design. Computer aided design tool MathCAD has been chosen as the environment for realizing the calculation program. Four versions of the design program have been made depending on the motor rotor type. The first rotor type is an axially slitted solid-rotor with steel end rings. The next one is an axially slitted solid-rotor with copper end rings. The third machine type is a solid rotor with deep, rectangular copper bars and end rings (squirrel cage). And the last one is a solid-rotor with round copper bars and end rings (squirrel cage). Each type of rotor has its own specialties but a general thread of design is common. This paper follows the structure of the calculating program and explains some features and formulas. The attention is concentrated on the difference between laminated and solid-rotor machine design principles. There is no deep analysis of the calculation ways are presented. References for all solution methods appearing during the design procedure are given for more detailed studying. This thesis pays respect to the latest innovations in solid-rotor machines theory. Rotor ends’ analytical calculation follows the latest knowledge in this field. Correction factor for adjusting the rotor impedance is implemented. The purpose of the created design program is to calculate the preliminary dimensions of the machine according to initial data. Obtained results are not recommended for exact machine development. Further more detailed design should be done in a finite element method application. Hence, this thesis is a practical tool for the prior evaluating of the high-speed machine with different solid-rotor types parameters.

Vibration analysis for Bearing outer race condition diagnostics

This paper investigates defect detection methodologies for rolling element bearings through vibration analysis. Specifically, the utility of a new signal processing scheme combining the High Frequency Resonance Technique (HFRT) and Adaptive Line Enhancer (ALE) is investigated. The accelerometer is used to acquire data for this analysis, and experimental results have been obtained for outer race defects. Results show the potential effectiveness of the signal processing technique to determine both the severity and location of a defect. The HFRT utilizes the fact that much of the energy resulting from a defect impact manifests itself in the higher resonant frequencies of a system. Demodulation of these frequency bands through use of the envelope technique is then employed to gain further insight into the nature of the defect while further increasing the signal to noise ratio. If periodic, the defect frequency is then present in the spectra of the enveloped signal. The ALE is used to enhance the envelope spectrum by reducing the broadband noise. It provides an enhanced envelope spectrum with clear peaks at the harmonics of a characteristic defect frequency. It is implemented by using a delayed version of the signal and the signal itself to decorrelate the wideband noise. This noise is then rejected by the adaptive filter that is based upon the periodic information in the signal. Results have been obtained for outer race defects. They show the effectiveness of the methodology to determine both the severity and location of a defect. In two instances, a linear relationship between signal characteristics and defect size is indicated.

A temperature predicting model for manufacturing processes requiring coiling

A model for predicting temperature evolution for automatic controling systems in manufacturing processes requiring the coiling of bars in the transfer table is presented. Although the method is of a general nature, the presentation in this work refers to the manufacturing of steel plates in hot rolling mills. The predicting strategy is based on a mathematical model of the evolution of temperature in a coiling and uncoiling bar and is presented in the form of a parabolic partial differential equation for a shape changing domain. The mathematical model is solved numerically by a space discretization via geometrically adaptive finite elements which accomodate the change in shape of the domain, using a computationally novel treatment of the resulting thermal contact problem due to coiling. Time is discretized according to a Crank-Nicolson scheme. Since the actual physical process takes less time than the time required by the process controlling computer to solve the full mathematical model, a special predictive device was developed, in the form of a set of least squares polynomials, based on the off-line numerical solution of the mathematical model.

Deregulation’s Impact on the Railway Freight Transport Sector’s Future in the Baltic Sea Region

The European transport market has confronted several changes during the last decade. Due to European Union legislative mandates, the railway freight market was deregulated in 2007. The market followed the trend started by other transport modes as well as other previously regulated industries such as banking, telecommunications and energy. Globally, the first country to deregulate the railway freight market was the United States, with the introduction of the Staggers Rail Act in 1980. Some European countries decided to follow suit already before regulation was mandated; among the forerunners were the United Kingdom, Sweden and Germany. The previous research has concentrated only on these countries, which has provided an interesting research gap for this thesis. The Baltic Sea Region consists of countries with different kinds of liberalization paths, including Sweden and Germany, which have been on the frontline, whereas Lithuania and Finland have only one active railway undertaking, the incumbent. The transport market of the European Union is facing further challenges in the near future, due to the Sulphur Directive, oil dependency and the changing structure of European rail networks. In order to improve the accessibility of this peripheral area, further action is required. This research focuses on topics such as the progression of deregulation, barriers to entry, country-specific features, cooperation and internationalization. Based on the research results, it can be stated that the Baltic Sea Region’s railway freight market is expected to change in the future. Further private railway undertakings are anticipated, and these would change the market structure. The realization of European Union’s plans to increase the improved rail network to cover the Baltic States is strongly hoped for, and railway freight market counterparts inside and among countries are starting to enhance their level of cooperation. The Baltic Sea Region countries have several special national characteristics which influence the market and should be taken into account when companies evaluate possible market entry actions. According to thesis interviews, the Swedish market has a strong level of cooperation in the form of an old-boy network, and is supported by a positive attitude of the incumbent towards the private railway undertakings. This has facilitated the entry process of newcomers, and currently the market has numerous operating railway undertakings. A contrary example was found from Poland, where the incumbent sent old rolling stock to the scrap yard rather than sell it to private railway undertakings. The importance of personal relations is highlighted in Russia, followed by the railway market’s strong political bond with politics. Nonetheless, some barriers to entry are shared by the Baltic Sea Region, the main ones being acquisition of rolling stock, bureaucracy and needed investments. The railway freight market is internationalizing, which is perceived via several alliances as well as the increased number of mergers and acquisitions. After deregulation, markets seem to increase the number of railway undertakings at a rather fast pace, but with the passage of time, the larger operators tend to acquire smaller ones. Therefore, it is expected that in a decade’s time, the number of railway undertakings will start to decrease in the deregulation pioneer countries, while the ones coming from behind might still experience an increase. The Russian market is expected to be totally liberalized, and further alliances between the Russian Railways and European railway undertakings are expected to occur. The Baltic Sea Region’s railway freight market is anticipated to improve, and, based on the interviewees’ comments, attract more cargoes from road to rail.

Methods of genetic diversity creation and functional display for directed evolution experiments

Protein engineering aims to improve the properties of enzymes and affinity reagents by genetic changes. Typical engineered properties are affinity, specificity, stability, expression, and solubility. Because proteins are complex biomolecules, the effects of specific genetic changes are seldom predictable. Consequently, a popular strategy in protein engineering is to create a library of genetic variants of the target molecule, and render the population in a selection process to sort the variants by the desired property. This technique, called directed evolution, is a central tool for trimming protein-based products used in a wide range of applications from laundry detergents to anti-cancer drugs. New methods are continuously needed to generate larger gene repertoires and compatible selection platforms to shorten the development timeline for new biochemicals. In the first study of this thesis, primer extension mutagenesis was revisited to establish higher quality gene variant libraries in Escherichia coli cells. In the second study, recombination was explored as a method to expand the number of screenable enzyme variants. A selection platform was developed to improve antigen binding fragment (Fab) display on filamentous phages in the third article and, in the fourth study, novel design concepts were tested by two differentially randomized recombinant antibody libraries. Finally, in the last study, the performance of the same antibody repertoire was compared in phage display selections as a genetic fusion to different phage capsid proteins and in different antibody formats, Fab vs. single chain variable fragment (ScFv), in order to find out the most suitable display platform for the library at hand. As a result of the studies, a novel gene library construction method, termed selective rolling circle amplification (sRCA), was developed. The method increases mutagenesis frequency close to 100% in the final library and the number of transformants over 100-fold compared to traditional primer extension mutagenesis. In the second study, Cre/loxP recombination was found to be an appropriate tool to resolve the DNA concatemer resulting from error-prone RCA (epRCA) mutagenesis into monomeric circular DNA units for higher efficiency transformation into E. coli. Library selections against antigens of various size in the fourth study demonstrated that diversity placed closer to the antigen binding site of antibodies supports generation of antibodies against haptens and peptides, whereas diversity at more peripheral locations is better suited for targeting proteins. The conclusion from a comparison of the display formats was that truncated capsid protein three (p3Δ) of filamentous phage was superior to the full-length p3 and protein nine (p9) in obtaining a high number of uniquely specific clones. Especially for digoxigenin, a difficult hapten target, the antibody repertoire as ScFv-p3Δ provided the clones with the highest affinity for binding. This thesis on the construction, design, and selection of gene variant libraries contributes to the practical know-how in directed evolution and contains useful information for scientists in the field to support their undertakings.

Terästankkien valmistusvaiheen kustannus- ja aikataulurakenteen määrittäminen

Diplomityössä tutkittiin erilaisilla loppuasennusmenetelmillä toimitettujen terästank-kien kustannus- ja aikataulurakennetta. Usein terästankit valmistetaan valmiiksi muotoon valssatuista levyistä työmaalla kasaanhitsaamalla. Tämä ei ole ainoa terästankin valmistusvaihtoehto, myös ruuvaus, niittaus, kiilaliitos ja konepajalla suuremmiksi kappaleiksi hitsaus ovat yleisesti käytössä. Terästankkien valmistuskustannuksiin vaikuttavat materiaali, esivalmisteiden työstäminen, kuljetus ja loppuasennus. Tankin valmistusmenetelmä ei merkittävästi vaikuta tankin materiaalikustannuksiin. Materiaalikustannuksiin vaikuttavat eniten käytettävä materiaali ja tankin geometriset ominaisuudet. Tankin esivalmisteiden valmistusaika määräytyy loppuasennusmenetelmästä. Pidempi esivalmistusaika lyhentää loppu-asennusaikaa. Kokonaisena toimitetussa tankissa esivalmistuksen osuus on suurempi kuin hitsatussa tankissa, mutta loppuasennusaika on vain murto-osa hitsattavan tankin loppuasennusajasta. Ruuvattavassa tankissa laippojen hitsaus levyihin lisää esivalmistusaikaa, kun rullattavassa tankissa aikaa vievät vaippalevyjen kasaanhitsaaminen ja rullaaminen. Tankin loppuasennustapa voidaan, etenkin halkaisijaltaan noin 10 m:llä tankeilla, valita kohdemaan mukaan, koska erot valmistuskustannuksissa ovat pieniä eri toimitusmuotojen välillä. Tosin kokonaisen 10 m halkaisijaltaan olevan tankin kuljettaminen ei aina ole mahdollista eikä kannattavaa. Sen sijaan halkaisijaltaan 5 m:llä tankeilla kokonaisena toimittaminen on varteenotettava vaihtoehto. Sopivin tankkivaihtoehto, kokonainen, hitsattava, ruuvattava tai rullattava, tulee miettiä aina tapauskohtaisesti, kohdemaan, hitsausosaamisen, kuljetusmahdollisuuksien ja loppuasennuspaikan mukaan.

Magnetic properties of multi-walled nanotubes on polysterene substrate

Nanotubes are one of the most perspective materials in modern nanotechologies. It makes present investigation very actual. In this work magnetic properties of multi-walled nanotubes on polystyrene substrate are investigated by using quantum magnetometer SQUID. Main purpose was to obtain magnetic field and temperature dependences of magnetization and to compare them to existing theoretical models of magnetism in carbon-bases structures. During data analysis a mathematical algorithm for obtained data filtration was developed because measurement with quantum magnetometer assume big missives of number data, which contain accidental errors. Nature of errors is drift of SQUID signal, errors of different parts of measurement station. Nanotube samples on polystyrene substrate were studied with help of atomic force microscope. On the surface traces of nanotube were found contours, which were oriented in horizontal plane. This feature was caused by rolling method for samples. Detailed comparison of obtained dependences with information of other researches on this topic allows to obtain some conclusions about nature of magnetism in the samples. It emphasizes importance and actuality of this scientific work.

Dynamic Analysis Model of Spherical Roller Bearings with Defects

Rolling element bearings are essential components of rotating machinery. The spherical roller bearing (SRB) is one variant seeing increasing use, because it is self-aligning and can support high loads. It is becoming increasingly important to understand how the SRB responds dynamically under a variety of conditions. This doctoral dissertation introduces a computationally efficient, three-degree-of-freedom, SRB model that was developed to predict the transient dynamic behaviors of a rotor-SRB system. In the model, bearing forces and deflections were calculated as a function of contact deformation and bearing geometry parameters according to nonlinear Hertzian contact theory. The results reveal how some of the more important parameters; such as diametral clearance, the number of rollers, and osculation number; influence ultimate bearing performance. Distributed defects, such as the waviness of the inner and outer ring, and localized defects, such as inner and outer ring defects, are taken into consideration in the proposed model. Simulation results were verified with results obtained by applying the formula for the spherical roller bearing radial deflection and the commercial bearing analysis software. Following model verification, a numerical simulation was carried out successfully for a full rotor-bearing system to demonstrate the application of this newly developed SRB model in a typical real world analysis. Accuracy of the model was verified by comparing measured to predicted behaviors for equivalent systems.

Vibrations in Rotating Machinery Arising from Minor Imperfections in Component Geometries

Vibrations in machines can cause noise, decrease the performance, or even damage the machine. Vibrations appear if there is a source of vibration that excites the system. In the worst case scenario, the excitation frequency coincides with the natural frequency of the machine causing resonance. Rotating machines are a machine type, where the excitation arises from the machine itself. The excitation originates from the mass imbalance in the rotating shaft, which always exists in machines that are manufactured using conventional methods. The excitation has a frequency that is dependent on the rotational speed of the machine. The rotating machines in industrial use are usually designed to rotate at a constant rotational speed, the case where the resonances can be easily avoided. However, the machines that have a varying operational speed are more problematic due to a wider range of frequencies that have to be avoided. Vibrations, which frequencies equal to rotational speed frequency of the machine are widely studied and considered in the typical machine design process. This study concentrates on vibrations, which arise from the excitations having frequencies that are multiples of the rotational speed frequency. These vibrations take place when there are two or more excitation components in a revolution of a rotating shaft. The dissertation introduces four studies where three kinds of machines are experiencing vibrations caused by different excitations. The first studied case is a directly driven permanent magnet generator used in a wind power plant. The electromagnetic properties of the generator cause harmonic excitations in the system. The dynamic responses of the generator are studied using the multibody dynamics formulation. In another study, the finite element method is used to study the vibrations of a magnetic gear due to excitations, which frequencies equal to the rotational speed frequency. The objective is to study the effects of manufacturing and assembling inaccuracies. Particularly, the eccentricity of the rotating part with respect to non-rotating part is studied since the eccentric operation causes a force component in the direction of the shortest air gap. The third machine type is a tube roll of a paper machine, which is studied while the tube roll is supported using two different structures. These cases are studied using different formulations. In the first case, the tube roll is supported by spherical roller bearings, which have some wavinesses on the rolling surfaces. Wavinesses cause excitations to the tube roll, which starts to resonate at the frequency that is a half of the first natural frequency. The frequency is in the range where the machine normally operates. The tube roll is modeled using the finite element method and the bearings are modeled as nonlinear forces between the tube roll and the pedestals. In the second case studied, the tube roll is supported by freely rotating discs, which wavinesses are also measured. The above described phenomenon is captured as well in this case, but the simulation methodology is based on the flexible multibody dynamics formulation. The simulation models that are used in both of the last two cases studied are verified by measuring the actual devices and comparing the simulated and measured results. The results show good agreement.