The position taken in this thesis is that a small and medium sized supplier makes a strategic choice to integrate their supply chain with industrialized house-building companies in order to deliver customer value and sustain competitive advantage. Customer values for industrialized house-building means delivery reliability, product quality, supply chain and market flexibility. Supply chain integration is the means for understanding customer requirements and to use supply chain resources efficiently through collaboration. The purpose of this thesis is to explore a small sawmill transition from single-minded focus on raw material optimization and increased production efficiency towards supply chain integration and customer focus in the industrialized house-building context. The thesis basis is a systematic literature review and five appended papers, based on a longitudinal case study at a small Swedish sawmill. Data has been collected through interviews, participant observations, and archival data during the period of 2010-2012. The theoretical gap is formed by the lack of consensus on supply chain integration. Viewing the criticism it is not clear how the constructs that constitute supply chain integration affect the possibility of succeeding with integration, how the integration should be measured, or how it affects the performance. Hence this thesis makes a holistic approach and collect empirical data trough method development on a strategic (business models, supply chain management), tactical (supply chain planning, sales and operations planning) and operational (value stream mapping, lean value delivery, simulation) supply chain integration process within industrialized house-building context. However, the findings do not conclusively prove or disprove the position. Findings indicate that small sawmills with limited resources and capabilities can employ methods of sales and operations planning, business model decomposition and value stream mapping enhanced decision making. The main contribution is the empirical data on supply chain integration divided and analyzed from strategic, tactical and operational process levels synthesized that with understanding of the importance of integrating these three levels dual perspective. Thus contribute with theoretical enhancement and reduction of the still-identifiable fragmentation of supply chain integration theory. / Godkänd; 2014; 20140423 (jarkko); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Jarkko Erikshammar Ämne: Träbyggnad/Timber Structures Avhandling: Supply Chain Integration for Small Sawmills in Industrialized House-Building Opponent: Professor Christine Pasquire, College of Art & Design and Built Environment, School of Architecture Design and the Built Environment, Nottingham Trent University, Nottingham, England Ordförande: Professor Lars Stehn, Avd för byggkonstruktion och -produktion, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Tisdag den 17 juni 2014, kl 09.30 Plats: F1031, Luleå tekniska universitet / Lean Wood Engineering, TräIN

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Nowadays most people tend to spend a major part of their lives indoors; therefore, the importance of withholding a good internal environment in our buildings is essential. What follows, the thermal indoor climate is strongly influencing the quality and comfort of life in residential areas. This essay will focus on thermal indoor climate situation in a student residence. Based on calculations, measurements and simulations from two different student apartments as well as data collected through a survey, this work will discuss whether the indoor climate complies with the requirements and standards for student housing and what improvement options are available. The survey showed dissatisfaction with the indoor temperature during summer and wintertime. Furthermore, the climate simulation demonstrated the increase in temperature during the summertime, which resulted in a greater dissatisfaction (PPD). Additionally, the calculations made to compare with the climate simulation have also shown that the apartments are getting too hot during summer. IDA ICE logged the relative humidity over a longer period of 1 year, resulting in a range between 5.8% -77.8%. Own measurements such as temperatures, relative humidity, carbon dioxide and exhaust airflows have been set against standards and requirements from authorities and deficiencies of the thermal indoor climate have been mapped. The apartments meet the standard of thermal indoor climate for student housing with one exception -the carbon dioxide content exceeds 1000 ppm in the apartment with the presence of two people. The exhaust airflow in both apartments was lower in our own measurements in comparison to what they were at the OVK protocol from 2014. The exhaust airflow in one apartment had a flow rate of 10 l / s higher than the dimensional flow rate, which indicates imbalance in the system. According to IDA ICE, too high and too low humidity was observed. This may indicate that the apartments do not have a satisfactory sun shading, which plays a significant role in the indoor climate. Using sun shading on all windows could reduce the temperature increase from solar radiation by 50% and the maximum operating temperature could be lowered by 4 degrees in IDA ICE. Using awnings as the sun shading solutions would also lower PPD's high peaks to 10%.

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Buildings subjected to impact and explosion are usually studied using large scale and highly nonlinear finite element model which are time-consuming. The first part of the thesis deals with the development of simple and accurate models for evaluating the nonlinear inelastic behaviour of steel frame structures subjected to impact. The research work in this part has produced four simplified models. The first model concerns with a 4DOF model that reproduces the behaviour of the impacted column. The restraining effect from the rest of the structure is modelled by an elastic spring, a head mass and a static load applied at the top of the column. In the second model, the impacted column is then further simplified using a SDOF model. The behaviour of the SDOF model is governed by an analytical force-displacement expressions of the column loaded by a located force. The maximum displacement of the impacted column can also be determined explicitly by adopting an energy-equivalent approach. Afterwards, in an effort to model the whole structure, two finite element models are developed. For these models, a co-rotational super-element that consists of a beam element and two generalized elasto-plastic hinges is obtained by performing a static condensation. An elastic flexible beam element is used in the first finite element model, whereas a rigid beam element is considered in the second one. In these models, inelasticity is concentrated at generalized elasto-plastic hinges which are modelled by combined axial-rotational springs. The behaviour of the hinges is uncoupled in the elastic range while an axial-bending interaction is considered in the plastic range making it possible to reproduce a wide range of cross-sections and joints. In addition, unilateral contact between rigid point masses is considered and the energy loss during impact is accounted by means of a restitution coefficient following Newton’s impact law. Energy-momentum scheme is used to solve the equations of motion produced by these models. The second part of the thesis concerns with the performance of the connectors in composite steel-concrete slabs under explosion. The purpose is to determine residual capacities of the shear connectors after being damaged by explosion using large-scale pull-out and push-out experimental tests and finite element simulations. / <p>QC 20171106</p>

A frame structure exposed to fire undergoes two types of changes due to the resulting temperature fields. The first is the thermal expansion of the structural members and the second is the degradation of the material strength and stiffness as temperature rises. Initially the thermal expansion dominates the response and the structural member (beam) is exposed to compressive forces due to restrained expansion, thus precipitating flexural buckling. At higher temperatures the mechanical material properties degrade. This fact, together with the high compressive forces in the bottom flanges of the beam often results in local buckling, followed by the formation of a plastic hinge close to the support region. The combination of transverse loads and the rising temperature leads to the development of excessive deflections in the beam. When temperature rises enough for the bending resistance of the beam to become insufficient, catenary action is introduced. The result is that the beam transitions to a stage where tensile forces appear due to the catenary action. In these different stages of the response of the structure the beam-to-column connection plays a crucial role and its robustness will determine if the structure will be able to maintain its integrity.The robustness of a structure in a fire situation greatly depends on the rotational capacity of the connection region. High rotational capacity is required at elevated temperatures since the steel beams lose their bending stiffness and exhibit increasingly large deflections under constant load. Beam deflections result in increasing rotations at the supports and may lead to collapse due to connection failure. Other possible failure modes may occur in the structural members, for example due to yielding in tension of the beam. The reverse channel has been proposed as a practical alternative to assemble beams to tubular columns. In a simple implementation, the bending moment generated in the joint due to rotation of the beam may be neglected; however, research efforts are being attempted to quantify the level of constraint. The typical arrangement of the connection type consists of a reverse channel with its flanges welded onto the face of concrete-filled tubular columns and the web bolted to the endplate of a beam. Thicknesses and depths of the reverse channel determine the level of rotational restraint at high temperature. The reverse channel has the ability to undergo catenary deformation in the tensile zone due to the applied rotation at the support and similarly it is relatively ductile in the compression zone. Overall, the reverse channel connection response is rather ductile in terms of its ability to undergo large rotational deformation as long as bolt failure is avoided through proper design.Various tests have been performed to study the behaviour of this type of connection such as full scale buildings, sub-frames, isolated joints and individual sections. The aim of these tests was to capture the connection behaviour in relation to other structural components in fire. This thesis focuses on the tests carried out on the connection components and their finite element modelling. A comprehensive parametric study was performed to assess the influence of different parameters on the behaviour of the connection component at elevated temperatures. The results from the finite element analyses have been utilized to validate analytical models that describe the behaviour of this type of connection at ambient and elevated temperature. Insight into the analytical models provides proper background to a structural designer to estimate the initial stiffness and understand the behaviour of the reverse channel in the connection. / En ramkonstruktion utsatt för brand påverkas på två olika sätt av temperaturhöjningen. För det första blir det en längdutvidgning av temperaturhöjningen och för det andra tappar materialet styrka och styvhet med ökande temperatur. Inledningsvis dominerar effekten av temperatur-utvidgningen. Denna leder till tryckande tvångskrafter i konstruktionen vilka kan leda till knäckning.Vid höga temperaturer sjunker materialets styvhet och styrka. Detta kan tillsammans med de höga tryckkrafterna leda till att flytleder bildas vid stöd. De stora tryckkrafterna kan också orsaka knäckning i balken och transversallasterna kan med den minskade styvheten på grund av temperaturhöjning ge upphov till mycket stora deformationer och balkens bärförmåga blir vid tillräckligt höga temperaturer otillräcklig. Vid tillräckligt stora deformationer övergår det statiska verkningssättet från böjning till linverkan. Under denna övergång spelar förbanden mellan balkar och pelare en central roll, och hur dessa klarar att hantera laster och deformationer avgör om hela konstruktionen kan klara belastningen.Hur en konstruktion klarar en brandbelastning beror i hög grad på hur förbanden mellan balkar och pelare klarar rotationer. En stor rotationskapacitet krävs vid höga temperaturer eftersom stålbalkar då har låg bärförmåga och deformationerna kan bli mycket stora även om lasterna är oförändrade. Stora deformationer i balkarna leder till stora rotationer i knutpunkterna vilket kan leda till att förbanden brister och hela konstruktionen kollapsar. Andra möjliga brottmoder kan vara kollaps av balkarna på grund av plasticering under drag. U-profilen har föreslagits som ett praktiskt alternativ för att ansluta balk till pelare. Rotationskapaciteten för ett sådant förband kan bedömas som försumbar, men forskningsinsatser görs för att bestämma den. En föreslagen utformning är att svetsa U-profilens flänsar till den betongfyllda pelaren med slutet tvärsnitt och livet fäst med skruvar i ändplåten på en balk. Rotationsstyvheten vid höga temperaturer kommer att bero på dimensioner på U-profilen. En U-profil har möjligheten att genomgå omvandlingen till linverkan i den dragna delen när den utsätts för ändrotation med den tryckta delen intakt. I allmänhet har ett förband med en U-profil möjlighet att klara stora rotationer under förutsättning att skruvförbandet är utformat på rätt sätt.Ett antal försök har genomförts för att studera hur föreliggande förband kan fungera i en byggnad, en del av en ram, enskilda förband och i tvärsnitt. Försöken har gjorts för att nå förståelse för hur förbandet fungerar tillsammans med andra konstruktionsdetaljer när de utsätts för brandbelastning. Denna avhandling fokuserar på försöken med delar ur förbandet och finit element modellering. En omfattande parameterstudie har gjorts för att förstå hur olika parametrar påverkar förbandets egenskaper vid förhöjd temperatur. Från FE-beräkningarna har analytiska modeller tagits fram som beskriver förbandets egenskaper vid medelhöga och höga temperaturer och dessa ger konstruktören möjlighet att uppskatta den ursprungliga styvheten hos förbandet med U-profil och förståelse för dess uppträdande. / <p>Godkänd; 2013; 20131008 (timhei); Tillkännagivande disputation 2013-11-11 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen, dubbel doktorsexamen LTU och University of Coimbra, Portugal. Namn: Tim Heistermann Ämne: Stålbyggnad/Steel Structures Avhandling: Stiffness of Reverse Channel Connections at Room and Elevated Temperatures Opponent: Professor Darko Beg, Head of Steel Structures, Ljubljana University, Ljubljana, Slovenien Ordförande: Professor Milan Veljkovic, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Vice ordförande: Assistant Professor Rui António Duarte Simões, Civil Engineering Department, University of Coimbra, Coimbra, Portugal Tid: Tisdag den 3 december 2013, kl 09.00 Plats: F1031, Luleå tekniska universitet</p>

The functional-based building regulations issued in 1994/95, made it possible to once again build higher buildings with timber structures in Sweden. At the same time there was a need to make the traditional project- oriented construction process more efficient, with prefabricated building systems and products as one possible solution. Since then, a number of timber housing companies have established product strategies and developed system solutions to meet the demands from different markets. In other European countries, changes in rules and regulations have positively facilitated the development of timber building products and systems and established new companies and strategies. Austria is one example, where architecture and technology are in focus, developing different product strategies in the timber housing industry. External factors and their changing, affect the formulation of viable business strategies in the timber housing industry. This dissertation aims to describe and analyse the strategic development of timber housing companies in Sweden and Austria. Strategy theories on the alignment of internal elements and external factors to create competitive advantage are applied in this dissertation. The results are based on empirical data gathered in a multiple case-study with two cases from Sweden and Austria, respectively. Result show that the strategic development of the Austrian timber housing companies was determined by the established conditions in the construction process. Timber structures already had strong positions in specific market segments; hence, the strategic behaviour of timber housing companies progressed with an inside-out approach. The strategic focus was to develop efficient internal processes that focus on design skills, flexible production facilities and on-site assembly resources to improve competitive advantage. The strategic development of the Swedish timber housing companies was based on what was possible from the changes in basic conditions, which partly diverted from the common and shared understanding in the construction process; hence the strategic behaviour of timber housing companies have had an outside-in approach to create competitive advantage. They have developed product platforms of standardised modules or elements and where cooperation with technical and system design complementors have been important to offer competitive timber building system solutions. The results indicate a strong correlation between basic conditions - construction process - firm conduct. Changes in basic conditions will give raise to firm conduct, different from the normative behaviour in the construction process, by firms with resources and capabilities by the changing basic conditions. / Möjligheten att bygga höga byggnader med trästomme i Sverige kom som en följd av införandet av funktionsbaserade byggregler i mitten av 1990-talet. Samtidigt fanns ett behov av att effektivisera den traditionellt projektorienterade byggprocessen där industriellt förtillverkade systemprodukter sågs som en möjlig lösning. Detta utgjorde drivkraften till att ett antal träbyggnadsföretag har skapats och utvecklat produktstrategier och systemlösningar för högre hus i trä. Även i ett europeiskt perspektiv har det skapats ökade möjligheter för träbyggprodukter inom husbyggandet via regeländringar, vilket påverkat företagens strategier. Ett exempel är Österrike där arkitektur och teknik varit förtecken i utvecklandet av olika produktstrategier inom träbyggnadsindustrin. Omvärldsfaktorer och dessas förändring påverkar hur träbyggföretag skapar och utvecklar sina företagsstrategier. Denna avhandling syftar till att beskriva och analysera den strategiska utvecklingen av träbyggföretag i Sverige och Österrike. Avhandlingen har sin teoretiska bas i strategiteorier, där passningen mellan interna och externa förutsättningar ligger till grund för hur företag utvecklar konkurrensfördelar. Resultaten är baserade på data insamlade via en multipel fallstudie där två fall från Sverige respektive Österrike ingick.Resultaten visar att de österrikiska träbyggföretagens strategiska utveckling har skett inom ramen för vad som är givet av den etablerade byggprocessen. Träbyggnader har haft sina givna marknader och företagens strategiska agerande har varit med ett inifrån-ut-perspektiv. Det strategiska agerande har präglats av att utveckla effektiva interna processer med fokus på konstruktionskunnande, flexibla produktionsmetoder och byggplatsåtaganden för att öka konkurrensförmågan. De svenska träbyggföretagens strategiska utveckling har skett inom ramen för vad som är möjligt utifrån de förändrade grundförutsättningarna, och delvis avvikande från normen i byggprocessen. Träbyggföretagen har haft ett utifrån-in perspektiv och utvecklat träbyggsystem baserade på standardiserade modul- eller planelement. Samarbeten med olika projekteringsresurser har varit viktiga för erbjudanden med hetsåtagande.Resultaten visar att det finns ett starkt samband i kopplingen mellan grundförutsättningar - byggprocess - företagsagerande. När förändringar i grundförutsättningar sker som avviker från byggprocessens etablerade norm skapas möjligheter för företag med passande resurser och erbjudanden. / Godkänd; 2008; 20081105 (ysko)

Redesigning buildings to improve their space efficiency and allow changes in use is often essential during their service lives to comply with shifts in living standards and functional demands.This may require the introduction of new openings in elements such as beams, walls, and slabs,which inevitably reduces their structural performance and hence requires repair or strengthening.However, there are uncertainties regarding both the effects of openings and the best remedial optionsfor them. Traditionally, two methods have been used to strengthen reinforced concrete (RC) walls with openings, these being either to create a frame around the opening using RC/steel membersor to increase the cross-sectional thickness. Currently, intervention in existing buildings must be minimal in order to minimise inconvenience caused by limiting the use of the structure during repairs. One option is to use externally-bonded fibre-reinforced polymers (FRPs). In this study, the author reports on an experimental investigation of the effectiveness of carbonFRP (CFRP)–based strengthening for restoring the axial capacity of a solid reinforced concretewall after cutting openings. Nine half-scale specimens, designed to represent typical wall panels in residential buildings with and without door-type openings, were tested to failure. The walls were tested in two-way action and subjected to axial loading with low eccentricity (defined as one sixth of the wall’s thickness) along the weak axis to represent imperfections due to thickness variation and misalignment of the panels during the construction process. An extensive instrumentation scheme was used to monitor the specimen’s behaviour during the loading cycles. In addition to classical approaches for measuring strains and displacements, optical 3D measurements were also acquired using the digital image correlation (DIC) technique. These provided better overviews of the failure mechanism by recording the crack pattern development and deformation of the walls throughout the loading history. Reducing the cross-sectional area by cutting out openings i.e. 25% (hereafter referred to as small opening) and 50% (hereafter referred to as large opening) led to 36% and 50% reductions in peak loads, respectively. In both situations the failure was brittle due to crushing of concrete with spalling and reinforcement buckling. The CFRP strengthening increased the axial capacity of walls with small and large openings by 34 – 50% and 13 – 27%, respectively. This partially restored theircapacities to 85 – 95% and 57 – 63% of their precutting capacity (i.e. solid wall), respectively. A procedure based on a rigid-plastic approach for evaluating the ultimate load of walls with cut-out openings that have been strengthened with FRPs was also proposed in this study. Predictions made using the proposed method agree closely with experimental results. / <p><strong>Examining Committee</strong>: Professor Karin Lundgren, Division of Structural Engineering, Department of Civil and Environmental Engineering, Chalmers University of Technology, Gothenburg, Sweden</p><p>Professor Henrik Stang, Section for Structural Engineering, Department of Civil Engineering, Technical University of Denmark, Lyngby, Denmark</p><p>Professor Mats Oldenburg, Division of Mechanics of Solid Materials, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, Sweden</p>

Demands for shorter lead times, customized buildings and high quality deliveries drive house-building firms to systematise work in their supply chains. A practice of reusing processes and technical solutions leads to the formation of platforms in industrialised house-building. Product platforms originate from industries employing a make-to-order strategy, where platforms are used to achieve efficient design and product development work. The house-building design phase, integrated in an engineer-to-order supply chain, has been identified as crucial for achieving an efficient production. In the design phase, design work combines platform predefinitions with project requirements. The aim of this thesis is to describe how house-building platforms are systematised, as well as propose a framework for the use and development of platforms over time.To expand the knowledge development and use of platforms in house-building design, case studies were conducted that collected data from interviews and observations as well as using archival data at two different companies. One was a Swedish industrialised house-building company, with many levels of platform predefinitions that use off-site production; the other was a Swedish company using several platforms employing industrialised methods for on-site production. The design work of over sixty building projects has been studied through following project managers, engineers and platform developers in their day-to-day work. The use in projects of predefinitions of functional requirements, components, processes and relationships has been compared and contrasted using platform and engineering design theories.The result of this research shows that, in an engineer-to-order production strategy, creative and systematic designs are combined. This combination is needed to create product uniqueness and thus it is important to understand and maintain the balance between commonality and distinctiveness within the platforms used in housebuilding projects. Continuously changing demands in construction hinder a fully predefined platform. Long cycle times in house-building demand a continuous flow of knowledge between platform and day-today work in projects. Hence, platform versions and product variants often become non-functional in an engineer-to-order supply chain, so methods to support the knowledge flow become necessary. The research findings show that design work, integrated into the supply chain of house-building, is a source of experience feedback for platformdevelopment.The conclusion is that a movement towards mass customization in house-building is possible using the product platform concept, if the platform is applied to projects using support methods with experience being continuously fed back to the platform from house-building projects. However, there is a risk that use of predefinition in platforms is made without considering the consequences. The reuse of predefined processes could limit innovation capability, increase the risk for imitation and organisational inertia. Too great a restriction of components in the house-building platform could limit the product offer and narrow the market segment. The study also shows that predefinitions might lead to an unbalanced focus on buildability instead of client satisfaction. / Krav på kortare ledtider, kundanpassat byggande och hög kvalitet på leveranser tvingar byggföretagen att systematisera arbetet i sina produktionsled. Genom att återanvända processer och tekniska lösningar kan det dagliga arbetet utvecklas inom plattformar för industriellt bostadsbyggande. Produktplattformar med syfte att stödja effektiv design och produktutveckling baseras på strategier för tillverka mot order produktion. Projekteringsfasen, som en integrerad del avbostadsbyggandets produktionskedja, har identifierats som avgörande för att erhålla en effektiv produktion. I projekteringsfasen kombineras fördefinitioner från plattformen med projektets krav. Syftet med denna avhandling är att beskriva hur bostadsplattformar kan systematiseras, och föreslå ett ramverk för användning och utveckling av plattformar över tid.För att fördjupa kunskapen om hur plattformar används och utvecklas i bostadsprojektering har fallstudier genomförts genom insamling av data via intervjuer, observationer och arkiv hos två olika företag. Ett svenskt industriellt bostadsbyggande företag med hög grad av fördefinering för prefabricerad produktion. Det andra företaget använder flera plattformar och industrialiserade metoder för platsbyggande produktion. Projekteringsarbete har studerats i över sextio bostadsprojekt genom att följa projektledare, ingenjörer och plattformsutvecklare i deras dagliga arbete. Användandet av fördefinierade funktionskrav, komponenter, processer och relationer har analyserats mot plattforms och designteorier.Forskningsresultatet visar att kreativt och systematiskt arbete kombineras i en konstruera-mot-order kontext. Kombinationen är nödvändig för produktens unikitet, och därför är balansen mellan repetition och variation viktigt för förståelse om och andvändande av plattformar i husbyggnadsprojekt. Ständigt föränderliga krav inom byggandet hindrar en fullt fördefinierad plattform. Långa cykeltider i bostadsbyggandet ställer krav på ett kontinuerligt flöde av kunskap mellan plattform och det dagliga arbetet inom byggprojekten. Plattformsversioner och produktvarianter blir ofta icke-funktionella i en konstruera-mot-order kontext, metoder behövs därför för att stödja flödet. Forskningsresultaten visar på att projekteringsarbete, integrerat i bostadsbyggandets leveranskedja, är en källa för erfarenhetsåterföring i utveckling av en plattform.Slutsatserna visar att en förändring mot effektivt kundanpassat bostadsbyggandet är möjlig om plattformar används tillämpade i projekt med stödjande metoder och kontinuerlig erfarenhetsåterföring från byggprojekten till plattformen. Däremot, finns det en risk att plattformar fördefinieras utan att reflektera över konsekvenserna. Användning av fördefinierade processer skulle kunna begränsa innovationsförmågan, öka risken för imitation och skapa förändringsmotstånd inom organisationer. Detaljering av komponenter i en bostadsplattform kan begränsa produktutbudet och minska marknadssegmentet. Studien visar också att fördefinitioner kan leda till obalanserad fokusering på byggbarhet istället för funktionalitet för kunden. / Godkänd; 2013; 20131003 (gusjan); Tillkännagivande disputation 2013-10-29 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Gustav Jansson Ämne: Träbyggnad/Timber Structure Avhandling: Platforms in Industrialised House-Building Opponent: Professor Brian Atkin, Project Management Academy, Queensland University of Technology, Brisbane, Australien Ordförande: Docent Helena Johnsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Torsdag den 21 november 2013, kl 10.00 Plats: F531, Luleå tekniska universitet