24 resultados para 290500 Mechanical and Industrial Engineering
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
The future of high technology welded constructions will be characterised by higher strength materials and improved weld quality with respect to fatigue resistance. The expected implementation of high quality high strength steel welds will require that more attention be given to the issues of crack initiation and mechanical mismatching. Experiments and finite element analyses were performed within the framework of continuum damage mechanics to investigate the effect of mismatching of welded joints on void nucleation and coalescence during monotonic loading. It was found that the damage of undermatched joints mainly occurred in the sandwich layer and the damageresistance of the joints decreases with the decrease of the sandwich layer width. The damage of over-matched joints mainly occurred in the base metal adjacent to the sandwich layer and the damage resistance of the joints increases with thedecrease of the sandwich layer width. The mechanisms of the initiation of the micro voids/cracks were found to be cracking of the inclusions or the embrittled second phase, and the debonding of the inclusions from the matrix. Experimental fatigue crack growth rate testing showed that the fatigue life of under-matched central crack panel specimens is longer than that of over-matched and even-matched specimens. Further investigation by the elastic-plastic finite element analysis indicated that fatigue crack closure, which originated from the inhomogeneousyielding adjacent to the crack tip, played an important role in the fatigue crack propagation. The applicability of the J integral concept to the mismatched specimens with crack extension under cyclic loading was assessed. The concept of fatigue class used by the International Institute of Welding was introduced in the parametric numerical analysis of several welded joints. The effect of weld geometry and load condition on fatigue strength of ferrite-pearlite steel joints was systematically evaluated based on linear elastic fracture mechanics. Joint types included lap joints, angle joints and butt joints. Various combinations of the tensile and bending loads were considered during the evaluation with the emphasis focused on the existence of both root and toe cracks. For a lap joint with asmall lack-of-penetration, a reasonably large weld leg and smaller flank angle were recommended for engineering practice in order to achieve higher fatigue strength. It was found that the fatigue strength of the angle joint depended strongly on the location and orientation of the preexisting crack-like welding defects, even if the joint was welded with full penetration. It is commonly believed that the double sided butt welds can have significantly higher fatigue strength than that of a single sided welds, but fatigue crack initiation and propagation can originate from the weld root if the welding procedure results in a partial penetration. It is clearly shown that the fatigue strength of the butt joint could be improved remarkably by ensuring full penetration. Nevertheless, increasing the fatigue strength of a butt joint by increasing the size of the weld is an uneconomical alternative.
Resumo:
Tutkielman tavoitteena on määritellä projektikontrolloinnin ja - riskijohtamisen roolit ja toiminnot saksalaisissa kone- ja tehdassuunnitteluteollisuusyrityksissä. Tämä on kvalitatiivinen tutkielma, jossa käytetään voimakkaasti kuvailevia metodeita. Materiaali tutkimuksen empiiriseen osaan kerättiin kyselykaavakkeen avulla. Kyselykaavakkeiden tulokset käsiteltiin Microsoft Office Access- ohjelmalla ja analysoitiin Microsoft Office Excel- ohjelmalla ja Pivot table- työkalun avulla. Tutkimustulokset osoittavat, että asianmukaisessa projektikontrollointi- ja riskijohtamismetodien käytössä ja käyttötiheydessä esiintyy puutteita saksalaisissa kone- ja tehdassuunnitteluteollisuusyrityksissä. Tehostamalla ja keskittymällä enemmän projektikontrollointi- ja riskijohtamismetodeihin ja prosesseihin sekä projektien että yritysten suorituskyky paranisi.
Resumo:
A variable temperature field sets exacting demands to the structure under mechanical load. Most of all the lifetime of the rotating drum structure depends on temperature differences between parts inside the drum. The temperature difference was known because of the measurements made before. The list of demands was created based on customers’ needs. The limits of this paper were set to the inner structure of the drum. Creation of ideas for the inner structure was started open minded. The main principle in the creation process was to create new ideas for the function of the product with the help of sub-functions. The sub-functions were created as independent as possible. The best sub-functions were combined together and the new working principles were created based on them. Every working principle was calculated separately and criticized at the end of the calculation process. The main objective was to create the new kind of structure, which is not based too much to the old, inoperative structure. The affect of own weight of the inner structure to the stress values was quite small but it was also taken into consideration when calculating the maximum stress value of the structure. Because of very complex structures all of the calculations were made with the help of the ProE – Mechanica software. The fatigue analyze was made also for the best structure solution.
Resumo:
This thesis introduces a real-time simulation environment based on the multibody simulation approach. The environment consists of components that are used in conventional product development, including computer aided drawing, visualization, dynamic simulation and finite element software architecture, data transfer and haptics. These components are combined to perform as a coupled system on one platform. The environment is used to simulate mobile and industrial machines at different stages of a product life time. Consequently, the demands of the simulated scenarios vary. In this thesis, a real-time simulation environment based on the multibody approach is used to study a reel mechanism of a paper machine and a gantry crane. These case systems are used to demonstrate the usability of the real-time simulation environment for fault detection purposes and in the context of a training simulator. In order to describe the dynamical performance of a mobile or industrial machine, the nonlinear equations of motion must be defined. In this thesis, the dynamical behaviour of machines is modelled using the multibody simulation approach. A multibody system may consist of rigid and flexible bodies which are joined using kinematic joint constraints while force components are used to describe the actuators. The strength of multibody dynamics relies upon its ability to describe nonlinearities arising from wearing of the components, friction, large rotations or contact forces in a systematic manner. For this reason, the interfaces between subsystems such as mechanics, hydraulics and control systems of the mechatronic machine can be defined and analyzed in a straightforward manner.
Resumo:
The purpose of this study was to investigate the nature of co-operation between a project owner and an outside engineering consultant in combined heat and power plant implementation projects. Moreover, as another focal subject of the study was to familiarize the purchasing behavior of the energy producer and how an outside engineering consultant participated into different stages of the purchasing process. The study was carried out as a multiple case study including altogether six Finnish power plant implementation projects that had been taken into commercial use during 1995 – 2015. By adjusting the findings of empirical interview data and comparing those to the theoretical framework concerning, among others, Finnish energy production, engineering consulting businesses, delivery methods of construction project and finally the purchasing process, it can be concluded that especially in the power plant implementation projects in the past have a great influence to decisions made during the project. The role of the main engineering consultant is to act as an assistant, who helps to achieve the project goals successfully rather than an advisor who only knows how the project should be conducted. At least in these five project cases this was the case, meaning that the final decision power always remaining with project owner.
Resumo:
The purpose of this thesis is to examine how the reporting of operations related to green supply chain management and industrial symbiosis has evolved in UPM, Fortum and Kemira within the last ten years. The focus is on the improved operations, which are studied based on annual reports of these companies. The study provides a deeper understanding of the nature of green supply chain management and industrial symbiosis as well as the possibilites that their combination offers. The research is part of the DemaNET research project The study indicates that the environmental regulations and reporting standards have forced the studied companies to report their operations related to green supply chain management and industrial symbiosis more in detail during the last ten years. The operations related to green supply chain management in the studied companies are more common compared to operations related to industrial symbiosis. Often these two operations were also partially integrated, indicating a hybrid model. Even though firms often used hybrid models they still focused mainly on greening the internal operations rather than finding alternative ways for symbiosis outside the organization. The integration of green supply chain management and industrial symbiosis is most likely to occur when mutually beneficial relationships align the interests of all parties, thus resulting in the co-creation of value. The findings suggest that identifying mutual benefits and the flow of by-products are the ones that companies should give more attention to.
Resumo:
The aim of this study is to understand the importance of b2b brands in different phases of the industrial buying process in the digital era. The research problem is approached by examining a b2b supplier brand in the context of gas supplier selection. The data was collected by interviewing individuals from ten different companies. The findings contribute to previous theory by showing that as industrial buying behaviour is eventually individual behaviour, brands can influence decision making. The relevance of a brand depends on individual’s personality and preferences. Digital media cannot be ignored in managing brand image as buyers are present in the online environment. The results reveal that traditional personal selling is, nevertheless, in a key role in brand image building and is a source of added value. The salesperson influences buyers’ perceived associations of a brand and gives the brand a face.
Resumo:
The aim of this thesis was to clarify willingness and suitability for entrepreneurship among students of Lappeenranta University of Technology (LUT). In addition factors that would explain academic achievement and if there were relationship between academic achievement and willingness or suitability for entrepreneurship were examined. Questionnaires were sent via e-mail to 800 students of LUT in summer 2007. Response percent was 29,6 %. Based on the collected answers factors of entrepreneurial motivation and academic achievement were analyzed using mainly Pearson’s correlation coefficient and factor analysis. In the light of these factors willingness and suitability for entrepreneurship and academic achievement were examined. The results indicated that 36,7 % of the respondents were willing and 11,4 % were suitable for entrepreneurship. The largest share of the willing ones was focused on Department of Mechanical Engineering, whereas the smallest share on Department of Environmental Technology. The largest shares of the suitable ones were on Departments of Mechanical and Electrical Engineering, and the smallest shares on Departments of Environmental, Chemical and Energy Technology. Academic achievement was affected by, among others, exercising and success in high school. Academic achievement and willingness or suitability for entrepreneurship didn’t correlate. Yet, from factors of entrepreneurial motivation internal locus of control correlated positively with academic achievement.
Resumo:
Nykyaikain ammattitaitovalmennus alkaa olla verrattavissa huippu-urheiluun ja sen sisältämiin valmennusprosesseihin. Tämän tutkimuksen tavoitteena oli kartoittaa ne prosessit, joita käyttämällä ammattitaitovalmennettava saadaan tiedollisesti ja taidollisesti mandollisimman hyvin valmennettua WorldSkills-tason kilpailuihin. Valittuja prosesseja soveltaen ohjeistetaan CAD-suunnittelun valmennus ja kokonaisvaltainen valmistautuminen kilpailuihin. Hyvänä taustapohjana on tutkimuksen tekijän omakohtainen osallistuminen Taitaja-2007 kilpailun järjestämiseen lajivastaavana CAD-suunnittelussa. Tutkimuksessa tehtiin myös kartoitus kilpailutoiminnan vaikuttavuudesta ja sen mandollisista vaikutuksista kone- ja metallialan koulutukseen hakeutuvien nuorten määriin. Tutkimuksen pääkohteina olivat Taitaja-kilpailujen järjestäjinä toimineet paikkakunnat ja koulutuksenjärjestäjät peräkkäisiltä vuosilta eli Turku, Tampere ja Joensuu. Tämän lisäksi Helsingissä järjestetty WorldSkills-2005 kilpailu aiheutti positiivisia vaikutuksia koko ammattitaitovalmennuksen kenttään ja sen esille nostamiseen ammatillisessa koulutuksessa. Näitä tietoja ja prosesseja voidaan käyttää hyväksi ammattitaitovalmennuksen kanssa toimivien oppilaitoksien, työpaikkojen ja valmentajien sekä muiden asiasta kiinnostuneiden tahojen jatkossa tehtävään valmennukseen liittyvään kehitystyöhön.
Resumo:
Even though the research on innovation in services has expanded remarkably especially during the past two decades, there is still a need to increase understanding on the special characteristics of service innovation. In addition to studying innovation in service companies and industries, research has also recently focused more on services in innovation, as especially the significance of so-called knowledge intensive business services (KIBS) for the competitive edge of their clients, othercompanies, regions and even nations has been proved in several previous studies. This study focuses on studying technology-based KIBS firms, and technology andengineering consulting (TEC) sector in particular. These firms have multiple roles in innovation systems, and thus, there is also a need for in-depth studies that increase knowledge about the types and dimensions of service innovations as well as underlying mechanisms and procedures which make the innovations successful. The main aim of this study is to generate new knowledge in the fragmented research field of service innovation management by recognizing the different typesof innovations in TEC services and some of the enablers of and barriers to innovation capacity in the field, especially from the knowledge management perspective. The study also aims to shed light on some of the existing routines and new constructions needed for enhancing service innovation and knowledge processing activities in KIBS companies of the TEC sector. The main samples of data in this research include literature reviews and public data sources, and a qualitative research approach with exploratory case studies conducted with the help of the interviews at technology consulting companies in Singapore in 2006. These complement the qualitative interview data gathered previously in Finland during a larger research project in the years 2004-2005. The data is also supplemented by a survey conducted in Singapore. The respondents for the survey by Tan (2007) were technology consulting companies who operate in the Singapore region. The purpose ofthe quantitative part of the study was to validate and further examine specificaspects such as the influence of knowledge management activities on innovativeness and different types of service innovations, in which the technology consultancies are involved. Singapore is known as a South-east Asian knowledge hub and is thus a significant research area where several multinational knowledge-intensive service firms operate. Typically, the service innovations identified in the studied TEC firms were formed by several dimensions of innovations. In addition to technological aspects, innovations were, for instance, related to new client interfaces and service delivery processes. The main enablers of and barriers to innovation seem to be partly similar in Singaporean firms as compared to the earlier study of Finnish TEC firms. Empirical studies also brought forth the significance of various sources of knowledge and knowledge processing activities as themain driving forces of service innovation in technology-related KIBS firms. A framework was also developed to study the effect of knowledge processing capabilities as well as some moderators on the innovativeness of TEC firms. Especially efficient knowledge acquisition and environmental dynamism seem to influence the innovativeness of TEC firms positively. The results of the study also contributeto the present service innovation literature by focusing more on 'innovation within KIBs' rather than 'innovation through KIBS', which has been the typical viewpoint stressed in the previous literature. Additionally, the study provides several possibilities for further research.
Resumo:
Tämän työn toimeksiantajaorganisaatio oli Lappeenrannan teknillisen yliopiston alainen, kauppatieteitä, teknologiaa ja tuotantotaloutta työssään yhdistävä tutkimusyksikkö, Technology Business Research Center, TBRC. Erään innovatiivisuustutkimusprojektin (InnoSpring) yhteydessä haluttiin selvittää myös oman tutkimusyksikön innovatiivisuuteen vaikuttavia, edistäviä ja estäviä tekijöitä. Tutkielman tavoitteena oli kartoittaa niitä seikkoja, jotka organisaation - tässä tapauksessa yliopiston tutkimusyksikön - henkilökunnan, projektityöntekijöiden, projektipäälliköiden sekä johdon mukaan vaikuttavat yksikön kykyyn luoda ja omaksua uutta, sen innovatiivisuuteen. Työ toteutettiin focus group-ryhmähaastattelumenetelmällä (kvalitatiivinen tutkimus), joihin osallistuivat omina ryhminään työntekijätaso, projektipäälliköt sekä johto.Haastattelut äänitettiin, litteroitiin ja koodattiin Atlas-Ti-ohjelmistolla. Loppuraportti verkostokuvineen luovutettiin tutkimuslaitokselle heinäkuussa 2005. Ryhmäkeskustelun teemoista ja kysymysten muodosta johtuen tulokset käsittelivät niin tutkimusyksikön nykyistä tilaa kuin eräänlaista "toivetilaa", millainen olisi ihanteellinen ja innovatiivinen työpaikka. Merkillepantavaa oli, että työssä tuli systemaattisesti esiin enemmän innovatiivisuutta edistäviä kuin ehkäiseviä seikkoja - vaikka osa edistävistä seikoista koskikin nimenomaan "toivetilaa". Keskustelluimpia teemoja olivat johtajuus,tavoitteellisuus ja strategian, yhteisen suunnan tarve. Samoin olemassa olevienprosessien kehittäminen, osaamisen (niin oman kuin koko organisaationkin) kokoaminen ja kehittäminen edelleen sekä tulosten jalkauttaminen.
Resumo:
Micronization techniques based on supercritical fluids (SCFs) are promising for the production of particles with controlled size and distribution. The interest of the pharmaceutical field in the development of SCF techniques is increasing due to the need for clean processes, reduced consumption of energy, and to their several possible applications. The food field is still far from the application of SCF micronization techniques, but there is increasing interest mainly for the processing of products with high added value. The aim of this study is to use SCF micronization techniques for the production of particles of pharmaceuticals and food ingredients with controlled particle size and morphology, and to look at their production on semi-industrial scale. The results obtained are also used to understand the processes from the perspective of broader application within the pharmaceutical and food industries. Certain pharmaceuticals, a biopolymer and a food ingredient have been tested using supercritical antisolvent micronization (SAS) or supercritical assisted atomization (SAA) techniques. The reproducibility of the SAS technique has been studied using physically different apparatuses and on both laboratory and semi-industrial scale. Moreover, a comparison between semi-continuous and batch mode has been performed. The behaviour of the system during the SAS process has been observed using a windowed precipitation vessel. The micronized powders have been characterized by particle size and distribution, morphology and crystallinity. Several analyses have been performed to verify if the SCF process modified the structure of the compound or caused degradation or contamination of the product. The different powder morphologies obtained have been linked to the position of the process operating point with respect to the vapour-liquid equilibrium (VLE) of the systems studied, that is, mainly to the position of the mixture critical point (MCP) of the mixture. Spherical micro, submicro- and nanoparticles, expanded microparticles (balloons) and crystals were obtained by SAS. The obtained particles were amorphous or with different degrees of crystallinity and, in some cases, had different pseudo-polymorphic or polymorphic forms. A compound that could not be processed using SAS was micronized by SAA, and amorphous particles were obtained, stable in vials at room temperature. The SCF micronization techniques studied proved to be effective and versatile for the production of particles for several uses. Furthermore, the findings of this study and the acquired knowledge of the proposed processes can allow a more conscious application of SCF techniques to obtain products with the desired characteristics and enable the use of their principles for broader applications.
Resumo:
Rautateillä käytettävät tavaravaunut ovat vanhenemassa hyvin nopeasti; tämä koskee niin Venäjää, Suomea, Ruotsia kuin laajemminkin Eurooppaa. Venäjällä ja Euroopassa on käytössä runsaasti vaunuja, jotka ovat jo ylittäneet niille suositeltavan käyttöiän. Silti niitä käytetään kuljetuksissa, kun näitä korvaavia uusia vaunuja ei ole tarpeeksi saatavilla. Uusimmat vaunut ovat yleensä vaunuja vuokraavien yritysten tai uusien rautatieoperaattorien hankkimia - tämä koskee erityisesti Venäjää, jossa vaunuvuokraus on noussut erittäin suosituksi vaihtoehdoksi. Ennusteissa kerrotaan vaunupulan kasvavan ainakin vuoteen 2010 saakka. Jos rautateiden suosio rahtikuljetusmuotona kasvaa, niin voimistuva vaunukysyntä jatkuu huomattavan paljon pidemmän aikaa. Euroopan ja Venäjän vaunukannan tilanne näkyy myös sitä palvelevan konepajateollisuuden ongelmina - yleisesti ottaen alan eurooppalaiset yritykset ovat heikosti kannattavia ja niiden liikevaihto ei juuri kasva, venäläiset ja ukrainalaiset yritykset ovat olleet samassa tilanteessa, joskin aivan viime vuosina tilanne on osassa kääntynyt paremmaksi. Kun näiden maanosien yritysten liikevaihtoa, voittoa ja omistaja-arvoa verrataan yhdysvaltalaisiin kilpailijoihin, huomataan että jälkimmäisten suoriutuminen on huomattavan paljon parempaa, ja näillä yrityksillä on myös kyky maksaa osinkoja omistajilleen. Tutkimuksen tarkoituksena oli kehittää uuden tyyppinen kuljetusvaunu Suomen, Venäjän sekä mahdollisesti myös Kiinan väliseen liikenteeseen. Vaunutyypin tarkoituksena olisi kyetä toimimaan monikäyttöisenä, niin raaka-aineiden kuin konttienkin kuljetuksessa, tasapainottaen kuljetusmuotojen aiheuttamaa kuljetuspaino-ongelmaa. Kehitystyön pohjana käytimme yli 1000 venäläisen vaunutyypin tietokantaa, josta valitsimme Data Envelopment Analysis -menetelmällä soveliaimmat vaunut kontinkuljetukseen (lähemmin tarkastelimme n. 40 vaunutyyppiä), jättäen mahdollisimman vähän tyhjää tilaa junaan, mutta silti kyeten kantamaan valitun konttilastin. Kun kantokykyongelmia venäläisissä vaunuissa ei useinkaan ole, on vertailu tehtävissä tavarajunan pituuden ja kokonaispainon perusteella. Simuloituamme yhdistettyihin kuljetuksiin soveliasta vaunutyyppiä käytännössä löytyvässä kuljetusverkostossa (esim. raakapuuta Suomeen tai Kiinaan ja kontteja takaisin Venäjän suuntaan), huomasimme lyhemmän vaunupituuden sisältävän kustannusetua, erityisesti raakaainekuljetuksissa, mutta myös rajanylityspaikkojen mahdollisesti vähentyessä. Lyhempi vaunutyyppi on myös joustavampi erilaisten konttipituuksien suhteen (40 jalan kontin käyttö on yleistynyt viime vuosina). Työn lopuksi ehdotamme uuden vaunutyypin tuotantotavaksi verkostomaista lähestymistapaa, jossa osa vaunusta tehtäisiin Suomessa ja osa Venäjällä ja/tai Ukrainassa. Vaunutyypin tulisi olla rekisteröity Venäjälle, sillä silloin sitä voi käyttää Suomen ja Venäjän, kuten myös soveltuvin osin Venäjän ja Kiinan välisessä liikenteessä.