Weld joint characteristics by nano-materials addition

The need for industries to remain competitive in the welding business, has created necessity to develop innovative processes that can exceed customer’s demand. Significant development in improving weld efficiency, during the past decades, still have their drawbacks, specifically in the weld strength properties. The recent innovative technologies have created smallest possible solid material known as nanomaterial and their introduction in welding production has improved the weld strength properties and to overcome unstable microstructures in the weld. This study utilizes a qualitative research method, to elaborate the methods of introducing nanomaterial to the weldments and the characteristic of the welds produced by different welding processes. The study mainly focuses on changes in the microstructural formation and strength properties on the welded joint and also discusses those factors influencing such improvements, due to the addition of nanomaterials. The effect of nanomaterial addition in welding process modifies the physics of joining region, thereby, resulting in significant improvement in the strength properties, with stable microstructure in the weld. The addition of nanomaterials in the welding processes are, through coating on base metal, addition in filler metal and utilizing nanostructured base metal. However, due to its insignificant size, the addition of nanomaterials directly to the weld, would poses complications. The factors having major influence on the joint integrity are dispersion of nanomaterials, characteristics of the nanomaterials, quantity of nanomaterials and selection of nanomaterials. The addition of nanomaterials does not affect the fundamental properties and characteristics of base metals and the filler metal. However, in some cases, the addition of nanomaterials lead to the deterioration of the joint properties by unstable microstructural formations. Still research are ongoing to achieve high joint integrity, in various materials through different welding processes and also on other factors that influence the joint strength.

Inventive design and product development of a mechanical element

The thesis is dedicated to enhancement and development of a Mechanism in Company X in order to increase its key parameters and approve its workability. Current Mechanism model is described in details. The basis of various analysis, models and theories that are reflecting the working process of the Mechanism are included in the thesis. According to these three directions of enhancements are chosen: from mechanical, tribological and conceptual points of view. As the result the list of improvements is presented. The new models of Mechanism are built. The efficiency and lifetime value are obtained in accordance with corresponding estimations. The comparative analysis confirms the necessity of conducted changes. Recommendations for the Company X specialists are represented in the thesis. Proposals for deeper research are also suggested.

Environmental Challenges in the Joint Border Area of Norway, Finland and Russia

This report examines the human impact on the subarctic environment of the joint border area of Norway, Finland and Russia. The aim is to present the current state and recent changes that have taken place in the region. The main threat to the environment is the Pechenganikel mining and metallurgical industrial combine in the towns of Nikel and Zapolyarny in the Kola Peninsula. Emissions from this complex include high levels of heavy metals, persistent organic pollutants and sulfur dioxide. Pollution, along with climate change, water level regulation and other anthropogenic effects, has affected the aquatic ecosystems in the joint border area. The main heavy metals in the area are copper and nickel, the highest concentrations of which are measured near the combine. Direct discharge of sewage into the river continues and airborne heavy metal particles are also deposited to areas farther away. Climate changeinduced increase in temperature and precipitation in the Kola Peninsula is evident. Water level regulation with seven hydropower plants in the Pasvik River have changed it into a series of lakes and lake-like reservoirs. This report discusses modelling, which was enabled to estimate the effect of climate change on Lake Inarijärvi and the Pasvik River hydrology, water level fluctuation and ecology and to follow the sulfur dioxide emissions emitted from the Pechenganikel. Effects of pollution on the nature and concentrations of the main pollutants were studied and climate change in the border area and its effects on the ecology were estimated. Also the effects of water level regulation on the ecological status of the aquatic ecosystems were addressed.

The best practices in the formation phase of Sino-Finnish joint ventures in China: For Finnish software companies

This study discusses the formation phase of Chinese-Finnish joint ventures in China. The purpose of this thesis is to create best practices for Finnish software companies in forming a joint venture with a local Chinese company in China. Therefore, the main research question, in what are the best practices for forming Sino-Finnish joint ventures in China for Finnish software firms, is examined through four different themes within the joint venture formation phase; the motives, the partner se- lection, the choice of a joint venture type and joint venture negotiations. The theoretical background of the study consists of literature relating to the establishment process of Sino-Western joint ventures in China. The empirical research conducted for this study is based on the expert interviews. The empirical data was gathered via nine semi-structured interviews with both Chinese and Finnish experts in software and technology industry, who have experience or knowledge in establishing Sino-Finnish joint ventures in China. Thematic analysis was used to cat- egorize and interpret the interview data. In addition, a thematic network was built to act as a basis of the analysis. According to the main findings, the main motives for Finnish software companies to establish a joint venture in China are lack of skills or experience, little resources to enter on their own, and China’s large market. The main motives for Chinese companies are to gain new technology or man- agerial skills, and expand internationally. The intellectual property rights (IPR) have recently im- proved a lot in China, but the Finnish companies’ knowledge on IPR is inadequate. The Finnish software companies should conduct a market and industry research in order to understand their po- sition in the market and to find a suitable location and potential joint venture partners. It is essential to define partner selection criteria and partner attributes. In addition, it is important to build the joint venture around complementary motives and a win-win situation between the joint venture partners. The Finnish companies should be prepared that the joint venture negotiations will be challenging and they will take a long time. The challenges can be overcome by gaining understanding about the Chinese culture and business environment. The findings of this study enhance understanding of the joint venture formation phase in China. This study provides guidelines for Finnish software companies to establish a joint venture in China. In addition, this study brings new insights to the Sino-Western joint venture literature with its soft- ware industry context. Future research is, however, necessary in order to gain an understanding of the advantages and disadvantages of a joint venture as an entry mode into China for Finnish soft- ware companies

Reputational Risk Management as a key element for business continuity and value maximization

This thesis reveals the topic of reputational risk management as a key element for business continuity and value maximization. The purpose of the work is to investigate reputational risk from the side of its definition, management (including legal requirements on this risk category) and measurement and to analyse reputational risk’s impact on business continuity and value maximization. To be able to do this, different respective articles, reports of financial institutions are gathered and constructive summaries and analysis are made. In order to deeply investigate the impact of reputational risk on business continuity and value maximization, it was chosen to study it from three aspects: 1) check the impact of stock valuation of 7 companies that experienced reputational catastrophe / risk, 2) analyse a case study on disagreements in management of reputational risk among case companies and impact on their respective performance, and 3) conduct a survey of financial sector companies in Liechtenstein to see how reputational risk management works in practice. The findings of the research showed a significant impact of reputation decadence on company’s value and trading volume, and showed crucial importance of post-crisis management for the company’s financial performance. The results of the qualitative research based on survey proved that companies consider reputational risk management as a one of the key elements for their business continuity and value maximization.

Real-time simulation of multibody systems with applications for working mobile vehicles

This dissertation describes an approach for developing a real-time simulation for working mobile vehicles based on multibody modeling. The use of multibody modeling allows comprehensive description of the constrained motion of the mechanical systems involved and permits real-time solving of the equations of motion. By carefully selecting the multibody formulation method to be used, it is possible to increase the accuracy of the multibody model while at the same time solving equations of motion in real-time. In this study, a multibody procedure based on semi-recursive and augmented Lagrangian methods for real-time dynamic simulation application is studied in detail. In the semirecursive approach, a velocity transformation matrix is introduced to describe the dependent coordinates into relative (joint) coordinates, which reduces the size of the generalized coordinates. The augmented Lagrangian method is based on usage of global coordinates and, in that method, constraints are accounted using an iterative process. A multibody system can be modelled as either rigid or flexible bodies. When using flexible bodies, the system can be described using a floating frame of reference formulation. In this method, the deformation mode needed can be obtained from the finite element model. As the finite element model typically involves large number of degrees of freedom, reduced number of deformation modes can be obtained by employing model order reduction method such as Guyan reduction, Craig-Bampton method and Krylov subspace as shown in this study The constrained motion of the working mobile vehicles is actuated by the force from the hydraulic actuator. In this study, the hydraulic system is modeled using lumped fluid theory, in which the hydraulic circuit is divided into volumes. In this approach, the pressure wave propagation in the hoses and pipes is neglected. The contact modeling is divided into two stages: contact detection and contact response. Contact detection determines when and where the contact occurs, and contact response provides the force acting at the collision point. The friction between tire and ground is modelled using the LuGre friction model, which describes the frictional force between two surfaces. Typically, the equations of motion are solved in the full matrices format, where the sparsity of the matrices is not considered. Increasing the number of bodies and constraint equations leads to the system matrices becoming large and sparse in structure. To increase the computational efficiency, a technique for solution of sparse matrices is proposed in this dissertation and its implementation demonstrated. To assess the computing efficiency, augmented Lagrangian and semi-recursive methods are implemented employing a sparse matrix technique. From the numerical example, the results show that the proposed approach is applicable and produced appropriate results within the real-time period.

Effect of loading type on the fatigue strength of symmetric and asymmetric welded joints made of ultra high strength steel

In this study, finite element analyses and experimental tests are carried out in order to investigate the effect of loading type and symmetry on the fatigue strength of three different non-load carrying welded joints. The current codes and recommendations do not give explicit instructions how to consider degree of bending in loading and the effect of symmetry in the fatigue assessment of welded joints. The fatigue assessment is done by using effective notch stress method and linear elastic fracture mechanics. Transverse attachment and cover plate joints are analyzed by using 2D plane strain element models in FEMAP/NxNastran and Franc2D software and longitudinal gusset case is analyzed by using solid element models in Abaqus and Abaqus/XFEM software. By means of the evaluated effective notch stress range and stress intensity factor range, the nominal fatigue strength is assessed. Experimental tests consist of the fatigue tests of transverse attachment joints with total amount of 12 specimens. In the tests, the effect of both loading type and symmetry on the fatigue strength is studied. Finite element analyses showed that the fatigue strength of asymmetric joint is higher in tensile loading and the fatigue strength of symmetric joint is higher in bending loading in terms of nominal and hot spot stress methods. Linear elastic fracture mechanics indicated that bending reduces stress intensity factors when the crack size is relatively large since the normal stress decreases at the crack tip due to the stress gradient. Under tensile loading, experimental tests corresponded with finite element analyzes. Still, the fatigue tested joints subjected to bending showed the bending increased the fatigue strength of non-load carrying welded joints and the fatigue test results did not fully agree with the fatigue assessment. According to the results, it can be concluded that in tensile loading, the symmetry of joint distinctly affects on the fatigue strength. The fatigue life assessment of bending loaded joints is challenging since it depends on whether the crack initiation or propagation is predominant.

The best practices in the formation phase of Sino-Finnish joint ventures in China: For Finnish software companies

This study discusses the formation phase of Chinese-Finnish joint ventures in China. The purpose of this thesis is to create best practices for Finnish software companies in forming a joint venture with a local Chinese company in China. Therefore, the main research question, in what are the best practices for forming Sino-Finnish joint ventures in China for Finnish software firms, is examined through four different themes within the joint venture formation phase; the motives, the partner se-lection, the choice of a joint venture type and joint venture negotiations. The theoretical background of the study consists of literature relating to the establishment process of Sino-Western joint ventures in China. The empirical research conducted for this study is based on the expert interviews. The empirical data was gathered via nine semi-structured interviews with both Chinese and Finnish experts in software and technology industry, who have experience or knowledge in establishing Sino-Finnish joint ventures in China. Thematic analysis was used to cat-egorize and interpret the interview data. In addition, a thematic network was built to act as a basis of the analysis. According to the main findings, the main motives for Finnish software companies to establish a joint venture in China are lack of skills or experience, little resources to enter on their own, and China’s large market. The main motives for Chinese companies are to gain new technology or man-agerial skills, and expand internationally. The intellectual property rights (IPR) have recently im-proved a lot in China, but the Finnish companies’ knowledge on IPR is inadequate. The Finnish software companies should conduct a market and industry research in order to understand their po-sition in the market and to find a suitable location and potential joint venture partners. It is essential to define partner selection criteria and partner attributes. In addition, it is important to build the joint venture around complementary motives and a win-win situation between the joint venture partners. The Finnish companies should be prepared that the joint venture negotiations will be challenging and they will take a long time. The challenges can be overcome by gaining understanding about the Chinese culture and business environment. The findings of this study enhance understanding of the joint venture formation phase in China. This study provides guidelines for Finnish software companies to establish a joint venture in China. In addition, this study brings new insights to the Sino-Western joint venture literature with its soft-ware industry context. Future research is, however, necessary in order to gain an understanding of the advantages and disadvantages of a joint venture as an entry mode into China for Finnish soft-ware companies.

Investigation of the fatigue performance of welded duplex stainless steel

Diplomityössä tutkitaan hitsatun duplex-teräksen, laatu: EN 1.4462 (Outokumpu laatu 2205) väsymislujuutta. Tutkimusmetodologia noudattaa sekä kokeellisia että laskennallisia menetelmiä. Kokeelliset menetelmät sisältävät hitsatun teräksen väsytystestaukset laboratoriossa, hitsausten jälkikäsittelyt (HiFIT) sekä perusaineelle ja hitseille tehtävät metallurgiset tutkimukset. Väsytyskokeista saatavia tuloksia verrataan kansainvälisen hitsausinstituutin (IIW) vahvistamiin rakennekohtaisiin standardeihin sekä kirjallisuudessa esiintyviin tutkimustuloksiin. Laskennalliset menetelmät sisältävät vertailulaskelmia tehollisen lovijännityksen (ENS) menetelmää hyödyntäen. Tehollisen lovijännityksen menetelmässä liitoksissa vaikuttavat teholliset lovijännitykset selvitetään elementtimenetelmän (FEM) avulla. Tulokset vahvistavat, että hitsauksella ja hitsausten jälkikäsittelyllä on suuri merkitys rakenteen kestoikään. Suurin osa väsytyskokeiden tuloksista osoitti parempia väsymiskestävyyden arvoja kuin rakennekohtaiset standardit, mutta liitosten liitosvirheiden todettiin heikentävän väsytyskestävyyttä. Jälkikäsittelyiden todettiin parantavan liitosten väsymiskestävyyden tuloksia ja todettiin tulosten olevan hyödynnettävissä mitoituksessa.

Peak Force Kelvin Probe Force Microscopy Investigation of ZrO2 Nanocomposites for Hygroelectricity Power Element

ZrO2 nanocomposites were investigated considering their perspective application in hygroelectric power elements. Scanning probe microscopy (SPM) techniques allowed to visualize the surface topography and electrical properties. In this work was compared spacial charge behaviour of sample in humid and dry air conditions. Also different SPM modes were compared. Kelvin probe force microscopy (KPFM) was applied to characterize the spacial charge distribution on surface of the sample. Measurements showed, that trapped charge is not dissipated and can be manipulated with low voltages. Humidity influence on the electric potential of the sample was shown.