To meet the demand of future building requirements, and to improve productivity and competitiveness, there is a need to modernize and revise the current practices in the wooden single-family house industry. In several other sectors, intensive work is being done to adapt to the anticipated fourth industrial revolution. The manufacturing industry has already begun its transformation with concepts such as smart manufacturing and Industry 4.0. So far, smart manufacturing has not been discussed to any significant extent for the wooden single-family house industry, even though it might be a way for this industry to improve productivity and competitiveness. The research presented in this thesis aims at increased knowledge about what smart manufacturing means for the wooden single-family house industry. This requires investigating what smart wooden house manufacturingis, what challenges that might be associated with it, and how smart wooden house manufacturing can be realized. At the core of this thesis is the conceptualization of smart wooden house manufacturing—when realized, it is expected to contribute to improve the competitiveness of the wooden single family house industry. The findings presented here are based on three Research Studies. Two studies were case studies within the wooden single-family house industry. The third study was a traditional literature review. The findings revealed two definitions and 26 components of smart wooden house manufacturing. At large, smart wooden house manufacturing emphasizes digital transformation with a focus on digital information flow, how to add information, information compilation, and information distribution between systems/programs and departments. Some of the challenges associated with smart wooden house manufacturing are, e.g. culture, competence and manual transfer of information between systems. The findings indicate similarities of smart wooden house manufacturing within certain components of industrialized house building and Industry 4.0, these components could enable the realization of smart wooden house manufacturing. / För att möta efterfrågan på framtida byggkrav och för att förbättra produktiviteten och konkurrenskraften finns det ett behov av att modernisera och revidera nuvarande tillvägagångssätt inom träsmåhusindustrin. I flera andra sektorer arbetas det intensivt med att anpassa sig till den förväntade fjärde industriella revolutionen. Tillverkningsindustrin har redan påbörjat sin omvandling med koncept som smart manufacturing och Industry 4.0. Hittills har smart manufacturing inte diskuterats i någon större utsträckning för träsmåhusindustrin, även om det kan vara ett sätt för denna industri att förbättra produktiviteten och konkurrenskraften. Forskningen som presenteras i denna avhandling syftar till ökad kunskap om vad smart manufacturing innebär för träsmåhusindustrin. Detta kräver undersökning av vad smart trähustillverkning är, vilka utmaningar som kan vara förknippade med det och hur smart trähustillverkning kan realiseras. Kärnan i denna uppsats är begreppsframställningen av smart trähustillverkning—när det realiserats förväntas det bidra till att förbättra konkurrenskraften för träsmåhusindustrin. Resultaten som presenteras här är baserat på tre forskningsstudier. Två studier var fallstudier inom träsmåhusindustrin. Den tredje studien var en traditionell litteraturstudie. Resultaten avslöjade två definitioner och 26 komponenter av smart träshustillverkning. Sammanfattningsvis betonar smart trähustillverkning digital transformation med fokus på digitalt informationsflöde, hur man lägger till information, sammanställning av information och informationsfördelning mellan system / program och avdelningar. Några av utmaningarna associerade med smart trähustillverkning är t.ex. kultur, kompetens och manuell överföring av information mellan system. Resultaten indikerar likheter mellan smart träshustillverkning inom vissa komponenter av industriellt husbyggande och Industry 4.0, dessa komponenter skulle kunna möjliggöra realiseringen av smart trähustillverkning.

Difficulties in characterizing the dynamic behavior of wood structures have hindered investigations into their performance under dynamic loading. Because of this, wood structures are treated unfavorably in seismic design codes, even though past damage assessment surveys after seismic events indicated generally satisfactory performance. To allow investigations into their performance and safety under dynamic loading, the energy dissipation mechanisms of wood joints and structural systems must be known and the hysteretic behavior modeled properly. This thesis presents a general hysteresis model for wood joints and structural systems, based on a modification of the Bouc-Wen-Baber-Noori (BWBN) model. The hysteretic constitutive law, based on the endochronic theory of plasticity and characterized by a single mathematical form, produces a versatile, smoothly varying hysteresis that models previously observed behavior of wood joints and structural systems, namely, (1) nonlinear, inelastic behavior, (2) stiffness degradation, (3) strength degradation, (4) pinching, and (5) memory. The constitutive law takes into account the experimentally observed dependence of wood joints' response to their past history (Le., the input and response at earlier times, or memory). Practical guidelines to estimate the hysteresis parameters of any wood joint or structural system are given. Hysteresis shapes produced by the proposed model are shown to compare reasonably well with experimental hysteresis of wood joints with: (1) yielding plate, (2) yielding nails, and (3) yielding bolts. To demonstrate its use, the proposed model is implemented in a nonlinear dynamic analysis program for single-degree-of-freedom (SDF) systems. System response from arbitrary dynamic loading, such as cyclic or earthquake-type loadings, can be computed. Three SDF wood systems are subjected to the Loma Prieta accelerogram to obtain their response time histories. Advantages of using the proposed model over currently available models in nonlinear dynamic analysis of more complex systems are identified. A multidegree-of-freedom shear building model incorporating the proposed hysteresis model is formulated but not implemented on a computer. / Master of Science

This project investigated the effects of process capability, line station operation efficiency, and line balance on the product throughput of a wooden door manufacturing process using time-and-motion study and simulation methods. The problem-solving approach DMAIC was used to identify root causes to the problems and implemented the process improvements for the production line efficiency and throughput based on lean manufacturing concepts. The investigation results indicated that the main operation of the wooden door manufacturing process was based on manual and semi-automatic operations. The process capability of whole operation before implementing process improvements was around 600 doors monthly. The coefficient of variation of process time for manual operation ranged from 12% to 23%. The semi-automatic operation ranged from 2% to 20%. The average station efficiency and throughput was 31% and 20 doors per day respectively. After implementing the removal of obvious motion waste, the processing time of the whole process reduced 22.9%. The reduced process time variation for manual operation ranged from 9% to 14%, and the semi-automatic operations ranged from 3% to 7%. The final product output had a 200% increase and the total process efficiency had 100% improvement after implementing the improved process flow design. Meanwhile, the average station efficiency and output increased to 61% and 65 doors per day, respectively.

Recently, the efforts involved in the digitization and digitalization of logistics processes have grown tremendously. In line with such efforts, we investigate the potential of the process-integrated measuring and load planning of large transport assets. More precisely, considering the case of a German timber processor and retailer, we implement a digital measuring system, which performs precise measuring of regularly shaped wooden assets. The cognitive system uses laser and vision sensors, and measurements can be performed during the asset’s transportation on a forklift. The resulting data can be used to conduct a comprehensive load planning for scheduled delivery tours. The performance of our measurement system is evaluated using a small example dataset of the use case at hand. The a-priori set goal of maximum deviations of 5 cm, 7 cm and 14 cm in height, width and length, respectively, are achieved in 89% of the test cases. The proposed load planning algorithm is integrated in a commercial tour planning service to verify the feasibility of serving several customers within the same tour. We present the method’s applicability to our described use case of integrated measurement and planning.

The purpose of the thesis work is to increase knowledge about older wood materials. The quality of the material and how to take care of it, restore it and reuse it, will be investigated. The aim of the report is to help reduce the amount of wood waste that the construction sector is responsible for and indicate the differences that exist between wood today and wood from the past. Due to the broad subject, there is a focus on wooden windows, which are used as examples in the report. The focus is carpentry wood andolder wood material before the middle of the 20th century. To achieve the goal, several interviews were conducted with experts in the field as well asa case study where older windows were replaced and what the consequences of that led to. The results show that wood production and the quality of timber have changed greatly. Before the year 1950, many natural forests that existed with slow-growing trees were used and much greater emphasis was placed on the quality of the material. Today's woodproduction is dominated by fast-growing trees and the trees are treated like a "bulk product". The trees are cut down all at once and sorted by area of use, rather than its individual characteristics. With the help of technological advances, the pursuit of efficiency in production has contributed to greater financial gain. Older wood materials turned out to have a higher quality compared to today's fast-growing timber. Properties of the older wood are higher density, denser annual rings, more resistant to moisture and above all a larger amount of heartwood. On the other hand, today's fast-growing woodmaterials are faster and easier to process. To carry out a restoration work of a window, competent craftsmen are required, of whichthere is currently a shortage. The demand for recycled wooden windows and interior doors has recently increased. Caring for older wooden windows is done by regular painting, scraping, and caulking of windows. The window replacement that wasinvestigated resulted in high costs and more emissions of carbon dioxide during the manufacture of the new windows, but energy consumption in the villa was reduced as the thermal insulation was improved.

The U.S. furniture industry has faced the challenge from increasing imports of furniture from foreign countries over the last decades. In the first part of this thesis, the import pattern of wooden bedroom furniture and the antidumping investigation against China were summarized, and furthermore, intervention analysis was employed to assess its impacts on the import value and unit price of China. The results revealed that the impact on import values was temporary but there was no significant impact on unit prices. The traditional suppliers have been substituted by the newly developing countries such as China and Vietnam. In the second part of this thesis, to explain the market structure change, a dynamic AIDS model was used to analyze the consumer behavior and evaluate the impacts of antidumping investigation on the major competitors in the second part. The results indicated that most imported wooden bedroom furniture can be substituted between suppliers and trade diversion occurred from China to Vietnam, Indonesia, and Brazil.

In light-frame residential construction wood-based composite panels used externally or internally are exposed to relative humidity and/or temperature changes. The subsequent moisture content change of the panels will result in two types of deformations as follows: 1. elastic deformation of the panel due to the constraint, 2. warpage of the panel due to the unbalanced expansion of the layers. Such deformations can cause unacceptable serviceability problems in light-frame wood construction. A model was developed to predict quantitatively the global deflection of wood-based composite panels exposed to relative humidity changes. The model was based on the constitutive relationship of the Classical Lamination Theory and the thermal stress analogy in composites. As an alternative solution, the applicability of the eccentrically loaded column formula was evaluated. The developed models were experimentally validated for OSB and plywood sheathing. Test variables included the panel type, exposure (symmetric and non-symmetric MC gradient) and specimen configuration (single span, multiple span). The comparison of measured and predicted deflections are presented. The important elastic and hygroscopic material properties were acquired through testing. Statistical analyses of test results are discussed. The uncertainty analysis was used to make statistical inference comparing the means of measured deflection to the uncertainty interval of predictions. Good agreement between predicted and measured deflections was found for single span test structures. Also, for double span structures the models predicted the experimental response fairly veil. Uncertainties in Me measurements made the prediction less reliable when symmetric moisture content gradient developed during the exposure. Due to its lower variability in material properties, the response of OSB sheathing to moisture content changes is more predictable. / Ph. D.

Today cities are consuming 75% of the world’s resources, which puts significant pressure on areas far from the cities themselves (Stockholm Resilience Center 2022). Food is among the largest drivers of global environmental change contributing to climate change, biodiversity loss, freshwater use, interference with the global nitrogen and phosphorus cycles and land-system change (C40 2024). This thesis describes a proposal for collecting and distributing rain- and stormwater within the context of urban farming and gardening. It explores how design can be a part of creating and promoting self-sufficient cities that are less resource intensive than they are today. Through the lens of Transition Design the proposal are aiming for a positive, system level change and a transition toward desirable long term futures. It can be divided in three sections, The Urban Farmer, The Vessel and The Wooden Aqueducts. The Urban Farmers would live in apartments throughout the city, forming a network of colleagues. The people in the neighborhood would get more understanding of the work that their local farmers do, and they would get more aware of where their food comes from. The vessel collects rain and stormwater and then distributes it when needed. It could act as an object not only for the use of water, but also as a way of sparking discussion, and just as it directs water to the trees, it just as well directs our minds and our attention towards them. The Wooden Aqueducts, inspired by the old craft, could potentially be created as a community practice to engage residents in the surrounding area. When the aqueducts are no longer needed they can remain at the site and be allowed to molder to make the cycles of organic matter visible and to challenge what is considered to be a well managed area. The Urban Farmer, The Vessel and The Wooden Aqueducts are all means to a future vision through a combination of short term, long term, small and big solutions and suggestions.

This study was performed in order to acquire key market information and information on raw material usage for the wood pallet and container industry in 2016. Historical trends in the wood pallet market were also analyzed between 1991-2016 using the results of previous Virginia Tech and U.S. Forest Service pallet surveys. Paper mail questionnaires and online questionnaires were sent to 2,520 companies that manufactured or wholesaled wood pallets and crates in the United States to obtain these data. The wooden pallet and container industry produced an estimated 508 million new wood pallets in 2016, which is a 22% increase since 2011. Approximately 35% of this was 48” x 40” pallets, which continues to be the dominant standardized pallet size. Approximately 39% of new wood pallets were custom sizes which is a significant decrease from the 60% share found in 2011. Stringer class pallets remained the dominant pallet class with 76% share while block pallets and skids only accounted for 21% and 3% of the market, respectively. Approximately, 38% of these new wood pallets were heat treated. Furthermore, an estimated 341 million pallets were recovered and sold as recycled/repaired or remanufactured pallets in 2016. The most common size of the recycled or remanufactured pallets was 48” x 40”, accounting for 69% of the recycled market. Ninety-one percent of recycled or remanufactured pallets were stringer class pallets while block class pallets made up the remaining 9%. Wood byproduct usage has changed since 2011. The conversion of broken pallets and wood waste to landscape mulch (37.5%) and animal bedding (4.2%) have declined with a proportional increase in other uses (28.3%). Biofuel conversion has remained steady since 2006 at 30%. / Master of Science / This study was performed in order to acquire key market information and information on raw material usage for the wood pallet and container industry in 2016. Historical trends in the wood pallet market were also analyzed between 1991-2016 using the results of previous Virginia Tech and U.S. Forest Service pallet surveys. Paper mail questionnaires and online questionnaires were sent to 2,520 companies that manufactured or wholesaled wood pallets and crates in the United States to obtain this data. As a whole, the wooden pallet and container industry has shown growth. The industry produced an estimated 508 million new wood pallets in 2016, which is a 22% increase since 2011. Furthermore, an estimated 341 million pallets were recovered and sold as recycled/repaired or remanufactured pallets in 2016. This is a small increase in the recycled/repaired or remanufactured pallet market. Wood byproduct usage has changed since 2011. The conversion of broken pallets and wood waste to landscape mulch (37.5%) and animal bedding (4.2%) have declined with a proportional increase in other uses (28.3%). Biofuel conversion has remained steady at 30%.

Trä är ett förnybart material till skillnad mot många andra byggnadsmaterial. Andelen trä inom byggnadsindustrin kan ökas genom att använda trädymlingsförband som ett substitut till skruvar och spikar. Skruvar och spikar tillverkas av metaller, vilka inte är förnybara material. Tillverkningsprocessen av metallbaserade material är mer energikrävande än den för trämaterial och har därför en större inverkan på vår miljö.Syftet med studien var att undersöka vidhäftningskapaciteten hos trädymlingsförband, olimmade och limmade av träslagen bok och furu. Fastsättningen av de olimmade trädymlingarna gjordes med insvällning. Insvällning innebar i studien att trädymlingarna först torkades, vartefter de placerades i en regel i inomhusklimat. Trädymlingarna strävade därefter att uppnå fuktkvotsjämvikt vilket medförde svällning. Vidhäftningskapaciteten för trädymlingsförband bör kunna konkurrera med utdragskapaciteten för till exempel spik för att vara praktiskt användbart.Trycktester har genomförts i laborationssalen i hus 45 på Högskolan i Gävle för att fastställa trädymlingarnas kraftupptagningsförmåga. Trycktesterna genomfördes i en drag- och tryckmaskin av modellen Shimadzu AG-X. Resultaten av testerna har sedan jämförts med den teoretiska utdragskapaciteten för spik. Karakteristiska hållfasthetsvärden har beräknats utifrån trycktestsresultaten.Resultatet av studien visar att endast de limmade trädymlingarna kan konkurrera med utdragskapaciteten hos spik. Limmade trädymlingar kan därför vara ett substitut till spik. Karakteristiska hållfasthetsvärden för limmad bok och limmad furu är 5,2 kN respektive 4,3 kN. / Wood is a renewable material, unlike many other building materials. The amount of wood used in the construction industry can be increased by using wooden dowels as a substitute for screws and nails. Screws and nails are made of metals, which are non-renewable materials. The manufacturing process of metal-based materials is more energy consuming than it is for wooden materials and therefore it has a greater impact on our global environment.The purpose of this study was to investigate the adhesion capacity of wooden dowel-joints, non-glued and glued made out of beech and pine. The attachment of the non-glued wooden dowels was achieved by swelling of the wood. Swelling was achieved by first drying the wooden dowels in an oven and then letting them acclimatize with the surrounding materials and the relative air humidity. The adhesion capacity of the wooden dowels should be able to compete with the withdrawal strength of nails to be practically useful.Tensile strength tests have been carried out in the laboratory in house 45 at the University of Gavle to determine the adhesion capacity of wooden dowel-joints. The tensile strength tests were performed with a Shimadzu AG-X machine. The results of the tests have been compared with the theoretical withdrawal strength for nails. Characteristic strength values have also been calculated from the tensile strength test results for the wooden dowels.The results of the study shows that only the glued wooden dowels can compete with the withdrawal strength of nails. Glued wooden dowels can therefore be a substitute for screws and nails. The calculated characteristic values for glued beech-dowels and glued pine-dowels are 5,2 kN respectively 4,3 kN.