Det forskas för närvarande kring trä som ett byggnadsmaterial och hur typiska knutpunkter angrips av laster. I denna studie studeras en kontorsbyggnad med primärbärverk trä. Byggnaden har fyra plan och ligger i Växjö. Målet och syftet med studien är att identifiera relevanta laster för byggnaden och med hjälp av handberäkningar beräkna de vertikala lasteffekterna. För de horisontala lasteffekterna användes datorprogrammet FEM-Design. Resultatet i studien visar relevanta lastuppgifter som verkar på byggnaden. Resultatet visar också att de vertikala lasteffekterna har ett linjärt samband i förhållande till antal våningar medan de horisontala lasteffekterna har ett exponentiellt samband i förhållande till antal våningar. Sambanden gäller endast för geografiska platser där snölasten och referensvindhastigheten är densamma som i Växjö kommun. / There are researches going on about timber as a construction material and how typical joints are affected by the loads. In this study an office building with a primary load- bearing structure of timber is being studied. The building has four floors and is located in Växjö. The aim and purpose of the study is to identify relevant load effects that are affecting the building. In order to calculate the horizontal load effects, a computer program called FEM- Design was used and the vertical load effects were calculated by hand. The results of the study show relevant load effect data that the building is being exposed to. The results also show that there is a linear relationship between the vertical load effects and the number of floors in the building. However, the relationship between the horizontal load effects and the number of floors is instead exponential. These relationships only apply to geographical locations where the snow load and the basic wind velocity are the same as in Växjö municipality.

Purpose: In this project work, the purpose is to perform an LCA as well as an LCC on two concept preschools, one with a wooden frame and one with a concrete frame. The result from the LCA is going to highlight, which of the building frames have the lowest environmental impact. In addition to the environmental impact, the project work  is going to include indoor climate together with energy use to get a broader view of the building’s overall performance. Method: This project work is in collaboration with Futurum Fastigheter i Örebro AB, where the authors have been instructed to perform an LCA on two concept preschools. One preschool has a wooden frame and the other has a concrete frame. The objective is to find out which of the buildings has the largest environmental footprint. In addition to this, the authors have evaluated an LCC together with an additional value tool. There are many tools to analyze the consequences from an environmental as well as an economic perspective. The report includes an LCA, LCC and an additional value tool. Result: The results show that the impact on CO2e/m2 for Bettorp was lower than Silva. Furthermore, the comparison between both preschools illustrated that Bettorp had lower emissions in all greenhouse categories except for carbon storage. The additional value tool portrays positive values for each preschool, although they differ. Conclusion: With the help of the software "One Click LCA" and "Visualisering och kvantifiering av mervärden vid energieffektivisering i offentlig sektor", the questionnaire has been answered and they all point to the wooden frame having a less environmental impacts along with a lower social cost of coal. The additional value tool was answered with the help of three employees at Futurum Fastigheter i Örebro AB. One of the participants concluded that there was no difference with regard to additional value between the preschools. The other two participants agreed that the preschool with a wooden frame provided a higher additional value compared to the other preschool.

This doctoral thesis concerns flanking transmission in light weight, wooden multi-storey buildings within the low frequency, primarily 20-120 Hz. The overall aim is to investigate how the finite element method can contribute in the design phase to evaluate different junctions regarding flanking transmission. Two field measurements of accelerations in light weight wooden buildings have been evaluated. In these, two sources; a stepping machine, and an electrodynamic shaker, were used. The shaker was shown to give more detailed information. However, since a light weight structure in field exhibit energy losses to surrounding building parts, reliable damping estimates were difficult to obtain. In addition, two laboratory measurements were made. These were evaluated using experimental modal analysis, giving the eigenmodes and the damping of the structures. The damping for these particular structures varies significantly with frequency, especially when an elastomer is used in the floor-wall junction. The overall damping is also higher when elastomers are used in the floor-wall junction in comparison to a screwed junction. By analysing the eigenmodes, using the modal assurance criterion, of the same structure with two types of junctions it was concluded that the modes become significantly different. Thereby the overall behavior differs. Several finite element models representing both the field and laboratory test setups have been made. The junctions between the building blocks in the models have been modeled using tie or springs and dashpots. Visual observation and the modal assurance criterion show that there is more rotational stiffness in the test structures than in the models. The findings in this doctoral thesis add understanding to how modern joints in wooden constructions can be represented by FE modelling. They will contribute in developing FE models that can be used to see the acoustic effects prior to building an entire house. However, further research is still needed. / Denna doktorsavhandling behandlar flanktransmission i flervåningshus med trästomme, inom det lågfrekventa området, främst 20-120 Hz. Det övergripande målet är att undersöka hur finita elementmetoden kan bidra i konstruktionsfasen för att utvärdera olika knutpunkters inverkan på flanktransmissionen. Två fältmätningar av accelerationer i trähus har utvärderats. I dessa har två olika lastkällor använts, i den första en stegljudsapparat och i den andra en elektrodynamisk vibrator (shaker). Det visades att shakern kan ge mer detaljerad information, men eftersom vibrationerna även sprider sig till omgivande byggnadsdelar vid fältmätningarna var det svårt att estimera tillförlitliga dämpningsdata även då shaker användes. Fältmätningarna följdes av två mätningar i laborationsmiljö. Dessa två experiment utvärderades med experimentell modalanalys, vilket ger egenmoder och dämpning hos strukturerna. Dämpningen för dessa trähuskonstruktioner varierar kraftigt med frekvens. Extra stora variationer registreras då en elastomer användes i knutpunkten mellan golv och vägg. Den totala dämpningen är generellt högre när elastomerer används i knutpunkten mellan golv och vägg i jämförelse med då knutpunkten är skruvad. Genom att analysera egenmoder och deras korrelationer (MAC), för samma trästruktur men med olika typer av knutpunkter, drogs slutsatsen att knutpunkten drastiskt förändrar strukturens dynamiska beteende. Flera finita elementmodeller av både fält- och laboratorieuppställningar har gjorts. I dessa har knutpunkterna mellan byggnadsdelar modellerats helt styvt eller med hjälp av fjädrar och dämpare. Visuella observationer av egenmoder och korrelationen dem emellan visar att det finns mer rotationsstyvhet i försöken än i finita elementmodellerna. Resultaten i denna doktorsavhandling har gett förståelse för hur knutpunkter i träkonstruktioner beter sig och kan simuleras med finit elementmodellering. Vidare kan resultaten bidra till utvecklingen av FE-modeller som kan användas för att kunna se de akustiska effekterna redan under konstruktionsstadiet. Dock behövs ytterligare forskning inom området.