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Stability Related Issues for High Wind Power Penetration : Exploring possibilities to enhance grid stability from synthetic inertia in a future scenarioEkstrand, Christian, Mansori, Farsad January 2020 (has links)
The future global energy transition favour renewables such as wind power, which is predicted to be one of the predominant sources harvesting abundant amounts of energy onwards. Consequently, causing several conventional synchronous generators to be decommissioned in a near future to achieve an overall reduction in greenhouse gases related to electricity generation. However, this evolution comes with new challenges regarding power system stability that could jeopardize the reliability of the grid as we today know it. Therefore, this thesis will examine how high penetrations of wind power are impacting each fundamental criterion regarding power system stability. For this purpose, are two different scenarios being carried out in Siemens PSS/E, representing a futuristic case as well as a present one. The simulation results themselves are being compared with analogies drawn from previous studies conducted within the field to determine if it can be improved.
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Integrating security into agile software development : A case study on the role of inertiaAndersson, Rasmus, Edström, Carl January 2022 (has links)
The security directives at Ericsson Group IT have recently been re-worked to apply to modern security requirements. For Ericsson's software development teams developing internal applications, security tools have been implemented into the daily workflow to follow these new directives. Before, security mainly was considered during the reviews and scheduled assessments of the software projects. The goal of these new tools is to add security to every part of the software development process. Security thus adds to the scope of work of the developers at Ericsson Group IT, which has, in the past, evolved from being solely a developer to being responsible for development and operations to development, security and operations. However, adding methods and tools to the developer's workflow can create inertia and friction in daily work. We intend to apply the concept of inertia to agile work practices to examine how small-scale projects are affected when new security tools and methods are introduced and implemented in the agile workflow. Research suggests that linked processes and methods should be put in place to achieve desirable results from the implemented tools and be integrated into the team's agile methodologies. The thesis aims to identify the factors that affect inertia by investigating and analysing the developers' use of methods and tools. As for data collection, a pilot study and a case study were applied to a team at Ericsson Group IT. The data was collected through qualitative surveys conducted on twelve proven factors regarding successfulness in work implementations. The data was then analysed through the Gioia methodology by compiling the collected data into first-order concepts and linking them to familiar second-order themes. These themes were then translated into aggregate dimensions synthesised from the study's theoretical framework. The results showed that several factors affected the change process: personnel training and education, appropriate communication, and adaptability to the change process. These are all factors attributing inertia to the change process, and awareness of these can help mitigate and facilitate a successful change process. Streamlining successful change processes is vital when integrating security as a requirement into an agile software development team.
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The influence of inertia on the rotational dynamics of spheroidal particles suspended in shear flowRosén, Tomas January 2014 (has links)
Dispersed particle flows occur in many industrial, biological and geophysical applications. The knowledge of how these flow behave can for example lead to improved material processes, better predictions of vascular diseases or more accurate climate models. These particle flows have certain properties that depend on single particle motion in fluid flows and especially how they are distributed both in terms of spatial position and, if they are non-spherical, in terms of orientation. Much is already known about the motion of perfectly spherical particles. For non-spherical particles, apart from their translation, it is important to know the the rotational motion due to local velocity gradients. Such studies have usually been restricted by the assumption that particles are extremely small compared to fluid length scales. In this limit, both inertia of the particle and inertia of the fluid can be neglected for the particle motion. This thesis gives a complete picture of how a spheroidal particle (a particle described by a rotation of an ellipse around one of its principal axes) behave in a linear shear flow when including both fluid and particle inertia, using numerical simulations. It is observed that this very simple problem possess very interesting dynamical behavior with different stable rotational states appearing as a competition between the two types of inertia. The effect of particle inertia leads to a rotation where the mass of the particle is concentrated as far away from the rotational axis as possible, i.e.\ a rotation around the minor axis. Typically, the effect of fluid inertia is instead that it tries to force the particle in a rotation where the streamlines of the flow remain as straight as possible. The first effect of fluid inertia is thus the opposite of particle inertia and instead leads to a particle rotation around the major axis. Depending on rotational state, the particles also affect the apparent viscosity of the particle dispersion. The different transitions and bifurcations between rotational states are characterized in terms of non-linear dynamics, which reveal that the particle motion probably can be described by some reduced model. The results in this theses provides fundamental knowledge and is necessary to understand flows containing non-spherical particles. / Flöden med dispergerade partiklar påträffas i många industriella, biologiska och geofysiska tillämpningar. Kunskap om hur dessa flöden beter sig kan bl.a. leda till förbättrade materialprocesser, bättre förutsägelser om hjärt- och kärlsjukdomar eller mer noggranna väderprognoser. Dessa flödens egenskaper beror på hur enskilda partiklar rör sig i en fluid och speciellt hur de är fördelade både i termer av position och, om de är icke-sfäriska, i termer av orientering. Mycket är redan känt om rörelsen av perfekt sfäriska partiklar. För icke-sfäriska partiklar är det inte bara translationen som är av intresse utan det är även viktigt att veta hur partiklarna roterar till följd av lokala hastighetsgradienter. Sådana studier har tidigare varit begränsade av antagandet att partiklarna är extremt små jämfört med fluidens typiska längdskalor. I denna gräns kan både partikelns och fluidens tröghet antas försumbar. Den här avhandlingen ger en komplett bild av hur en sfäroidisk partikel (en partikel som beskrivs av en rotation av en ellips runt en av dess huvudaxlar) beter sig i ett linjärt skjuvflöde när tröghetseffekter inkluderas. Resultaten har erhållits genom numeriska simuleringar. Det visar sig att detta enkla problem är väldigt rikt på olika dynamiska beteenden med flera stabila rotationstillstånd som uppstår tilll följd av både partikel- och fluidtröghet. Inverkan av partikeltröghet leder till en rotation där massan av partikeln är koncentrerad så långt ifrån rotationsaxeln som möjligt, d.v.s. en rotation runt lillaxeln. Den typiska inverkan av fluidtröghet är istället att fluiden försöker påtvinga partikeln en rotation där strömlinjer förblir så raka som möjligt. Primärt leder detta till att partikeln istället roterar runt storaxeln. Beroende på rotationstillstånd, så har partikeln även olika inverkan på den märkbara viskositeten av partikeldispersionen. De olika övergångarna och bifurkationerna mellan rotationstillstånd är karaktäriserade i termer av icke-linjär dynamik, vilket visar på att partikelrörelserna förmodligen kan beskrivas med en reducerad modell. Resultaten i denna avhandling är därför fundamental kunskap och ett nödvändigt steg mot att förstå beteendet av flöden med dispergerade, icke-sfäriska partiklar. / <p>QC 20140328</p>
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Design of Eccentric Double Amplitude Vibration Drum Roller Shaft with Improved Mass Moment of Inertia : Product Development of Compaction EquipmentBlad, Marika, Tynnerstål Balog, Alexander January 2020 (has links)
Road construction is important to make transports safe and sustainable. To compact asphalt an amount of energy needs to be conducted into the material either by static pressure or dynamic vibrations. An asphalt-roller compact the material and increases its load-bearing capacity. An eccentric shaft that generates vibrations is attached inside the roller drums. The shaft has two modes, varying between high eccentricity with slower pulses and low eccentricity with faster pulses. The study has been performed with the purpose to decrease the mass moment of inertia by redesigning the present eccentric shaft and verifying the new concepts with linear and non-linear FEM simulations. The new models were to have the same functional properties as the present eccentric shaft. The current cross-section of the shaft was changed to a cross-section of a circle in the periphery. This was done by adding all features in new geometry to a simple shaft base and creating an analysis chain. To create the new lengthwise design brainstorming was used to generate ideas. The ideas were then sorted by using a Pugh matrix. CAD was used to model the concepts with the desired eccentric properties. Simulation in FEM software was used to acquire information about the behaviors during operation. Academic validation and useful information have been gathered by doing a literature review. Two resulting concepts with properties fulfilling the prevailing restrictions. The circular cross-section in the periphery was adapted and the eccentric properties were kept. The simulation results from FEM software ended satisfactorily within limits for both execution in steel and ductile iron. For both concepts the mass moment of inertia was minimized, with 40.5 % in steel and in ductile iron with 42.0 % and 42.6 %. An analysis chain has been performed showing that a cross-section with a circular geometry is optimal when the intention is to minimize the mass moment of inertia. It is possible to minimize the mass moment of inertia without negatively affecting the eccentric properties. The lengthwise design of a shaft with eccentric properties has been studied and simulated. Two concepts with varied lengthwise designs have been created with conserved eccentric properties and significantly decreased mass moment of inertia. The concepts can compose a good basis to continue investigating the lengthwise design which hopefully ends in a manufacturable eccentric shaft that contributes to environmental asphalt construction with low energy usage. / Tillverkning av vägar är viktigt för att transporter ska kunna utföras på ett säkert och hållbart sätt. För att packa asfalt behövs en mängd energi överföras till materialet genom statiskt tryck eller dynamiska vibrationer. En asfaltsvält packar materialet och ökar dess belastningsförmåga. En excentrisk axel som genererar vibrationer sitter inuti trummorna på välten. Denna axel har två lägen som varierar mellan att ha hög excentricitet med lägre puls samt låg excentricitet med högre puls. Studien har genomförts med syftet att minska den nuvarande excenteraxelns masströghetsmoment genom att designa om den samt verifiera nya koncept med linjära och icke-linjära FEM beräkningar. De nya modellerna skulle behålla samma funktionella egenskaper som den nuvarande excenteraxeln. Det nuvarande tvärsnittet i XY-planet ändrades till en cirkel i rotationsaxlens periferi, genom att lägga till alla funktioner med nya tvärsnitt på en enkel axelbas i en analyskedja. En ny design i längsled påbörjades med brainstorming för att generera nya idéer. Idéerna sorterades sedan med hjälp av en Pugh-matris. Koncepten modellerades sedan med önskade excentriska egenskaper i CAD. FEM-mjukvara användes för att simulera koncepten och samla information om beteenden under körning. Akademisk validering och användbar information samlades in i en litteraturstudie. Arbetet resulterade i två koncept med egenskaper som uppfyllde rådande krav. Det cirkulära tvärsnittet i periferin behölls och likaså de excentriska egenskaperna. FEM resultaten visade sig hamna tillfredsställande under gränserna med materialen stål och segjärn. För båda koncepten minskade masströghetsmomentet varav 40.5 % i stål och 42.0 % respektive 42.6 % i segjärn. En analyskedja har genomförts som visat att ett tvärsnitt av en cirkel i periferi är optimalt med intentionen att minska masströghetsmomentet. Det är möjligt att minska masströghetsmomentet utan att påverka de excentriska egenskaperna negativt. Designen längs med en axel med excentriska egenskaper har studerats och simulerat. Två koncept med varierad design har modellerats, koncepten har behållna excentriska egenskaper och betydligt minskat masströghetsmoment. Koncepten kan utgöra gott underlag för fortsatt undersökning av designen i längdled. Förhoppningsvis kan det i sin tur resultera i en tillverkningsbar excentrisk axel som bidrar till miljövänligare asfaltskonstruktion med låg energiåtgång.
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Framtagning av konceptsmodell för mekanisk avskiljning av feltryckta wellpapparkNilsson, Albin, Fallström, Johan January 2021 (has links)
This thesis was made for EMBA Machinery AB and includes a product development process with the result of a concept model. EMBA is a company that develops and manufactures machines for the global corrugated board industry and wants to extend their solutions with a system that automatically removes the misprinted corrugated boards. The idea is to incorporate the system with the already existing processing flow and should be combined with the existing video system that validate the print quality. The concept model is a concept of the mechanical parts needed for the solution and can be used as a foundation for further work towards a product for the market. To produce this concept model methods for divergent problem solving were used. Several concept solutions were created and evaluated with the purpose of finding the best one. This concept was then developed further into a 3D-model of all the interlocking machine- and construction elements, whom in detail demonstrates the removal of misprinted boards. Calculations, which included determining moment of inertia and an acceleration curve, were also done based on data from this model with the intent of testing the plausibility of the solution and to offer a theoretical foundation on which to base further work with this concept. / Det här examensarbetet utfördes åt EMBA Machinery AB och innefattar en produktutvecklingsprocess med slutresultat i en konceptmodell. Företaget utvecklar och tillverkar i dag maskiner för den globala wellpapp-industrin och önskar nu komplettera sitt utbud med ett system som automatiskt sorterar bort wellpappark som erhållit felaktigt grafiskt tryck. Detta är tänkt att kunna inkorporeras i deras befintliga processeringsflöde och skall kombineras med befintlig videoteknik för validering av det grafiska trycket. Konceptmodellen som tas fram är således en potentiell lösning av de mekaniska delar som samverkar i sållningen av feltryckta ark och är tänkt som en grund för vidare arbete att ta fram en marknadsfärdig produkt. I processen att ta fram denna konceptmodell tillämpades metoder för divergent problemlösning där flera lösningskoncept genererades och värderades i syfte att hitta det bästa. Detta koncept utvecklades sedan till en mer detaljerad representation av lösningen i form av en 3D-modell av de samverkande maskin- och konstruktionselementen, vilken i detalj demonstrerar hur det valda konceptet löser sållningen av feltryckta ark. Beräkningar, vilka innefattade framtagning av tröghetsmoment och accelerationskurva, utfördes även med data från denna modell i syfte att testa lösningens rimlighet och att erbjuda en teoretisk grund att jobba vidare med i fortsatt arbete av konceptet.
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Exploring the relation between stakeholder inertia and product requirementsTing, Fang, Yiweihua, Huang January 2020 (has links)
User inertia is a real innovation adoption problem that cannot be seen or grasped. How to overcome user inertia while introducing innovation has become a key factor in today's society. Based on the background of requirements engineering, the goal of this thesis is to study and understand the relationship between user inertia and innovation adoption, including whether the type of innovation has an impact on user adoption and how to use strategies to reduce this impact. Through an online survey of 60 users and a systematic literature review of a series of articles, we have concluded the following points: RI has a greater impact on user inertia, while II has almost no impact; neither RI nor II has a significant impact on user satisfaction. Not only that, but through literature review, we have also concluded a comprehensive strategy to deal with the adoption problem caused by user inertia.
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Locating drivers of inertia in digital transformation : A case study of IT systems implementation driving holistic change in an incumbent organizationWinberg, Sissela, Bolinder, Ebba January 2022 (has links)
Past research provides little to no in-depth research regarding digital transformation; ittends to be portrayed as a very holistic and simplified process that organizations oftenimplement to stay competitive. One of the biggest barriers to digital transformation isconsidered to be inertia, we argue that concerning a digital transformation within anincumbent organization there could be more guidelines regarding how inertia emerges. Bybreaking down the components to see what is causing more of a barrier than necessary.Conducting a qualitative case study of an industrial organization located in Sweden. Withearlier research on digital transformation and inertia, we concluded that organizationsmust manage these concerns cohesively by continuously balancing their key roles,organizational structure, communication, and integration. We hope that our thesis canhelp create an understanding for incumbent organizations to realize and prevent inertiafrom emerging as part of future digital transformation.
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Flexural performance of FRP reinforced concrete beamsKara, Ilker F., Ashour, Ashraf 04 1900 (has links)
yes / A numerical method for estimating the curvature, deflection and moment capacity of FRP reinforced concrete beams is developed. Force equilibrium and strain compatibility equations for a beam section divided into a number of segments are numerically solved due to the non-linear behaviour of concrete. The deflection is then obtained from the flexural rigidity at mid-span section using the deflection formula for various load cases. A proposed modification to the mid-span flexural rigidity is also introduced to account for the experimentally observed wide cracks over the intermediate support of continuous FRP reinforced concrete beams.
Comparisons with experimental results show that the proposed numerical technique can accurately predict moment capacity, curvature and deflection of FRP reinforced concrete beams. The ACI-440.1R-06 equations reasonably predicted the moment capacity of FRP reinforced concrete beams but progressively underestimated the deflection of continuous ones. On the other hand, the proposed modified formula including a correction factor for the beam flexural rigidity reasonably predicted deflections of continuous FRP reinforced concrete beams. It was also shown that a large increase in FRP reinforcement slightly increases the moment capacity of FRP over-reinforced concrete beams but greatly reduces the defection after first cracking.
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Breaking Free From Financial Inertia : The Barriers Causing and Enablers Mitigating Financial Inertia in Circular Business Model TransitionsArbenius, Paula, Norling, Elias January 2023 (has links)
Background: Regulations and Governments prompt companies to reassess their practices and align with sustainability standards. It emphasizes a transition towards circular business practices, which requires large amounts of capital to commit to the adoption of circularity fully. The transportation sector is a prime example of an industry undergoing a significant circular transformation due to its environmental impact. Circular servitization has complemented the circular transformation by offering products as services instead of selling them outright. This has had severe financial statement implications since the operations differ from linear practices and requires large investments. Financial institutions still assume techniques, modulation, and evaluation processes adapted for linear purposes, which creates obstacles to capturing the value circular business models generate. Subsequently, financial institutions are hesitant to fund circular business models due to the perception of increased risk. Hence, financial inertia occurs and hinders the development of circular businesses. Purpose: This research adopts the perspective of financial institutions and examines the barriers and enablers that impact companies' transitions to circular business models, leading to or mitigating financial inertia. Method: The study is qualitative and adopted an abductive approach to contrast theory and findings with the interpretive research paradigm. The primary data was collected from eleven different respondents from a Swedish financial institution. Sampling was done non-randomly with a purposive sample and a convenience input to gather data from respondents who were part of the financial institution and knowledgeable in the circular transition. Findings: The aim of the study was to answer two research questions regarding barriers causing, and enablers mitigating financial inertia. The findings provided three soft and six hard barriers relating to financial techniques, modeling, and evaluation methods, along with internal competence about circularity, stakeholder involvement, and regulations. Additionally, the study found three soft and six hard enablers which could be interpreted as underlying drivers for mitigating financial inertia.
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Mechanical characterization of strain-hardening cement-based composites under impact loadingHeravi, Ali Assadzadeh 01 December 2020 (has links)
Strain hardening cement-based composites (SHCC) and textile reinforced concrete (TRC) are two types of novel cementitious materials which can be used for strengthening structural elements against impact loading. Under tensile loading, these composites exhibit a strain hardening behavior, accompanied with formation of multiple cracks. The multiple cracking and strain hardening behavior yield a high strain and energy absorption capacity, thus making SHCC and TRC suitable materials for impact resistant structures or protective layers.
The design and optimization of such composites for impact resistant applications require a comprehensive characterization of their behavior under various impact
loadings. Specifically, the rate dependent behavior of the composites and their constituents, i.e. matrix, reinforcement, and their bond, need to be described.
In the context of dynamic testing, SHCC, TRC and their constituents require customized experimental setups. The geometry of the sample, ductility of the material, the need for adapters and their influence on the measurements, as well as the influence of inertia are the key aspects which should be considered in developing the impact testing setups.
The thesis at hand deals with the development process of various impact testing setups for both composite scale and constituent scale. The crucial aspects to be taken into account are discussed extensively. As a result, a gravity driven split-Hopkinson tension bar was developed. The setup was used for performing impact tension experiments on SHCC, TRC and yarn-matrix bond. Moreover, its applicability for performing impact shear experiments was examined. Additionally, a mini split-Hopkinson tension bar for high speed micromechanical experiments was designed and built. In the case of compressive loading, the performance of SHCC was investigated in a split-Hopkinson pressure bar.
The obtained results, with focus on tensile experiments, were evaluated concerning their accuracy, and susceptibility to inertia effects. Full-field displacement measurement obtained by digital image correlation (DIC) was used in all impact experiments as a tool for visualizing and explaining the fracture process of the material in conjunction with the standard wave analysis performed in the split-Hopkinson bars.Moreover, the rate dependent behaviors of the composites were clarified with respect to the rate dependent behavior of their constituents.
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