<p>Idag blir det allt vanligare med träbyggnader högre än två våningar. Detta tillsammans med en modern arkitektur som ger stora öppna planlösningar ställer höga krav på bjälklagen i träbyggnader. Problematiken med långa spännvidder för bjälklag i trä är att klara kraven för svikt och nedböjning. Dessa krav måste uppfyllas för att säkerställa funktioner hos andra byggdelar och för att människor inte ska uppleva att golvet sviktar eller vibrerar på ett obehagligt sätt.</p><p>Ett träbjälklag bestående av limmade balkar av sidobräder har utvecklats. Bjälklaget är utformat av balkar med I-tvärsnitt i primärriktningen och rektangulära balktvärsnitt i sekundärriktningen. Examensarbetet omfattar laborativa provningar och beräkningar dels för att bestämma en böjelasticitetsmodul för varje enskild limmad balk och dels för att bestämma styvhetsegenskaperna för bjälklaget.</p><p>De limmade träbalkarna ingår i ett forskningsprojekt vid Växjö universitet finansierat av KK-stiftelsen, som syftar till att undersöka möjligheterna att tillverka en konkurrenskraftig produkt genom att i grönt tillstånd (otorkat) limma ihop bräder från stockens yttre delar till balkar. Balkarna levererades limmade och hyvlade till universitet där en böjelasticitetsmodul först bestämdes för varje enskild balk. Därefter monterades balkarna ihop till ett fullskaligt bjälklag som provades med olika försöksuppställningar/lastfall varvid deformationen mättes upp. Dessa deformationer blir underlag för att bestämma bjälklagets styvhet.</p><p>Böjstyvheten i primärriktningen uppgår till 17,55 x 1012 Nmm2/m enligt beräkningar baserade på laborativa resultat. Böjstyvheten i sekundärriktningen uppgår till 4,5 % av primärriktningens böjstyvhet, dvs. 0,79 x 1012 Nmm2/m. Sammanfattningsvis kan man säga att böjstyvheten är hög i båda riktningar i jämförelse med vanliga träbjälklag.</p> / <p>In Sweden it becomes more and more common with wood buildings higher than two floors. This along with a modern architecture that gives big open plan solutions sets high requirements on the floor systems in wood buildings. The complexes of problems with long spans for floor systems in wood are to match the requirements for elasticity and deformation. These requirements must be met in order to ensure functions of other construction components, and not be unpleasant for people to walk on with respect to vibrations.</p><p>A wooden floor system consisting of green glued side wood sections has been developed. The floor system is made with I-profiled beams in the primary direction and rectangular cross-sections in the secondary direction. This diploma work is based on that through elaborative testing and numeric calculations to decide the stiffness properties for each individual green glued side wood section and for the floor system.</p><p>The glued side wood sections are included in a project at Växjö University, which is financed by the KK-foundation. The sections were delivered glued and planed to the university where the stiffness properties were first determinded for each individual section. Then, the sections were assembled to one fully sized floor system that was exposed to different experiments as the deformation was measured. These deformations were later used in order to decide the stiffness of the floor system.</p><p>The stiffness in the primary direction was prescribed to 17,55 x 1012 Nmm2/m after calculations using results from the tests. The stiffness in the secondary direction amounts to 4,5% of the primary directions stiffness, i e. 0,79 x 1012 Nmm2/m. To sum up, one can say that the stiffness is high in both directions compared to regular wooden floor systems.</p>

<p>I samband med att intresset för att bygga högre trähus har ökat så krävs nya lösningar för att t.ex. kunna möta efterfrågan på stora öppna ytor och långa spännvidder. Träbjälklag med lång spännvidd har dock oftast svårigheter med att klara kraven på svikt och vibrationer. Ett nyutvecklat förslag på träbjälklag som förmodas klara dessa krav bättre än traditionella träbjälklag har varit utgångspunkten för detta examensarbete där syftet har varit att undersöka bjälklagets styvhet. Detta gjordes laborativt genom att bygga och testa en prototyp av det föreslagna bjälklaget och genom att en numerisk modell baserad på finita element metoden togs fram och användes för att studera hur olika parametrar påverkar bjälklagets styvhetsegenskaper.</p><p>Bjälklagets design bygger på fackverksprincipen i primärriktningen och på balkverkan i sekundärriktningen. De ingående komponenterna har kommit prefabricerade till Växjö universitet där de har monterats ihop till ett fullskaligt bjälklagselement. Elementet har sedan utsatts för ett antal belastningsfall där nedböjningarna uppmätts vilka sedan givit underlag för att få värden på bjälklagets effektiva styvhetsegenskaper.</p><p>Både de laborativa och de simulerade resultaten visar på en hög böjstyvhet i primärriktningen d.v.s. 18,9•106 Nm2/m [EI/b] respektive 18,6•106 Nm2/m [EI/b]. Även böjstyvheten i sekundärriktningen är hög d.v.s. motsvarar 21,2 % respektive 17,1 % av styvheten i primärriktningen.</p><p>I beräkningsmodellen har det dessutom undersökts hur ett övre lager av spånskivor inverkar på bjälklagets styvhet.</p> / <p>The interest for building higher and larger wooden houses has increased in Sweden during the last decade resulting in higher requirements on the technical performance of such structures in order to met demands on large open surfaces and large spans of floors. Wooden floor systems with large spans often have difficulties, however, to meet the vibration requirements. A novel floor system, likely to handle the vibration requirements better than traditional wooden floor systems, is the basis for this master thesis. The purpose is to examine the stiffness of the floor by building and testing a prototype and by producing a numerical model based on the finite element method.</p><p>In the longitudinal, main load-bearing direction the floor system works as a truss with flanges of longitudinal oriented timber members and web diagonals of transversely oriented members. In the transverse direction the web diagonals work as beams. The components were prefabricated elsewhere and assembled at Växjö University into a prototype. The prototype was then exposed to a number of different load cases. Deflections were measured and stiffness properties of the floor were derived. In addition to the experimental analysis the numerical model was used to calculate deflections when subjected to different load cases and for evaluating the principal stiffness properties of the floor.</p><p>Both the experimental and the calculated results using the numerical model show high bending stiffness in the longitudinal direction, EI/b = 18,9•106 Nm2/m and 18,6•106 Nm2/m respectively. Also the bending stiffness in the transversal direction is high and equivalent to 21,2 % or 17,1 % (testing and simulation respectively) of the bending stiffness in the longitudinal direction. Using numerical analysis, also the effect on the stiffness of adding an upper layer of a 22 mm particleboard was examined.</p>

No description available.

Hollow-core flooring units are designed as simply supported members. However, frequently in construction, continuity is established between the units and supporting structure by the addition of insitu topping concrete and steel reinforcement. This change in structural form can result in negative bending moments and axial forces being induced in the floor by seismic and other structural actions. Significant negative moments are induced by load combinations that include the effects of seismic forces due to vertical ground motion. The focus of this research was two failure mechanisms possible under these loading conditions, a flexural failure and a shear failure. Both failure mechanisms were investigated analytically and experimentally. A brittle flexural failure was observed experimentally in a sub assembly test that contained starter bars and mesh reinforcement in the insitu topping concrete. The failure occurred at loads lower than those predicted using standard flexural theory. It appears that, due to the prestressing and low reinforcement ratio of the topping concrete, the assumption that plane sections remain plane is not appropriate for this situation. It is proposed that a strain concentration factor be introduced to account for the effects of tension stiffening. This factor improves the correlation between observed and predicted flexural strength. The second failure mode investigated was a flexure shear failure in a negative moment zone. Flexural cracks reduce the shear strength of a reinforced concrete member. Analytical predictions suggest that some hollow-core floor details could be prone to this type of brittle failure. A flexure shear failure was not observed experimentally; however, this does not eliminate the possibility of this failure mode. A summary of other failure mechanisms possible in hollow-core flooring is also presented. All failure modes should to be considered as part of establishing a hierarchy of failure in the design or retrofit of hollow-core floors.

Dubens dugno raumenų aktyvinimas yra labai specifinis: dėl minėtų raumenų lokalizacijos pacientams yra sudėtinga įsivaizduoti, suprasti bei pajausti jų susitraukimą ir atliekamą funkciją. Kitas apsunkinantis veiksnys yra tas, kad daugumai pacientų dubens dugno raumenys asocijuojasi su intymumu ir lytiniu gyvenimu, ir jie vengia bei gėdisi spręsti šią problemą. Kita vertus, specialistams, dirbantiems su asmenimis, nelaikančiais šlapimo, sudėtinga įvertinti teisingą dubens dugno raumenų susitraukimą bei atliekamų pratimų efektyvumą. Šie apribojimai ir skatino ieškoti alternatyvių šlapimo nelaikymo bei dubens dugno raumenų disfunkcijų sprendimo būdų, įrodant egzistuojančius tiriamųjų raumenų funkcinius ryšius, jų poveikį funkciniams vyrų rodikliams po radikalios prostatektomijos. Šiame darbe taikant atskirų raumenų grupių aktyvinimą ir vertinant tiriamų raumenų fizinius rodiklius buvo ieškoma funkcinių sąsajų tarp dubens dugno, diafragmos ir liemens raumenų. Tikimasi, kad šio tyrimo rezultatai, išvados ir parengtos praktinės klinikinės rekomendacijos bus naudingos visiems reabilitacijos srities specialistams įvairiuose paciento gydymo etapuose, gydytojams urologams bei ginekologams, tiesiogiai susiduriančiais su asmenimis, turinčiais dubens dugno raumenų disfunkcijas. Sudarytos namų programos padės pacientams spręsti ne tik su šlapimo nelaikymu susijusias problemas, bet ir bus profilaktinė priemonė asmenims, esantiems padidintos rizikos grupėje. / Activation of pelvic floor muscles is extremely specific: due to the localization of the mentioned muscles, it is difficult for the patients to visualize, understand and feel the contraction and performed function. Another puzzling factor is the fact that many patients associate pelvic floor muscles with intimacy and sexual life and, therefore, try to avoid and are embarrassed to solve the problem. On the other hand, specialists working with patients with urinary incontinence find it difficult to evaluate a proper contraction of pelvic floor muscles and efficiency of performed exercises. These limitations have stimulated search for alternative solutions for urinary incontinence and pelvic floor muscles dysfunctions with the aim to prove existing functional relations between the studied muscles as well as their influence on the functional characteristics in men after radical prostatectomy. This particular thesis was aimed at finding functional associations between pelvic floor, diaphragm, and trunk muscles by applying activation of separate muscle groups and evaluating physical parameters of the studied muscles. It is expected that the results, conclusions, and prepared practical clinical recommendations of this research will be of use for all rehabilitation specialists in various stages of treatment, as well as for doctors urologists and gynaecologists, who deal directly with individuals possessing pelvic floor muscle dysfunctions.

This thesis contains explanations about the reasons why residents prefer apartment housing to low rise housing far away from the central business district. And it also investigates the facts that affect residents&rsquo / and producers&rsquo / apartment housing choice. As a dominant housing provision type, apartment housing is produced every location in urban space in Ankara. Therefore the study begins with investigating the formation and growth of apartment housing in Ankara by introducing spatial variation of apartment housing. With the help of building and population censuses, distribution of 400 quarters in the Greater Ankara Municipality borders with respect to building and population density, building features, share of apartment housing and average number of storeys are analyzed. FAR values are calculated and analyzed from the CBD to western direction to introduce the change in building densities. Lastly a questionnaire survey is done to find out whether differentiation of building and environment attributes of apartment housing that are produced in different location of urban area are well-matched with their residents&rsquo / preferences. At the end of the analysis differentiation of housing structure of the city clearly comes out. While it is expected that the height of housing structure is decreasing by going far away from the CBD, it is found increasing along certain directions such as western and south-western. However by moving at western direction FAR decreases from 2 to 0,75 which states different characteristics of housing structure even if high average number of storey. As a result apartment housing provisions at different locations offer different lifestyles with their building and environmental characteristics.

Urban land prices have important effects on urban development and locational distribution of land-uses. Housing is one of those sectors. There are high-density residential areas covering high-rise apartments at the city center where the land prices are quite high. Here, sizes of the plots and the housing units are relatively small. However, land prices begin to decrease with the increasing distance from the city center and the production of low-density, low-rise housing which is economically unfeasible at the center turns to be feasible for the housebuilders at the outskirts. Low-rise houses at the urban fringe provides various opportunities for the households. In these areas, plots and housing units are relatively larger due to cheap and available land. In addition to this, better urban services, quiet and clean environment as well as privacy contribute to create a livable urban environment. However, households living in low-rise housing units are subject to high transportation and maintenance costs. It is expected that they would compensate these costs with larger housing units, prestigious urban environment and many opportunities that their neighborhoods offer. Urbanization processes may be differ from one country to another with respect to the socio-economic and political structures, and the environmental characteristics. In that sense, low-rise housing areas at the urban fringe of Ankara were found to be developed highly compatible with urban land use theories / but different from the processes experienced in developed countries, to some extent. With regard to these, low-rise housing development in Ankara is discussed according to plan decisions, housebuilders, households and urban development pattern, considering the theoretical basis and historical processes.

The sound insulation demands for dwellings and public building has increased over the years as the number of sound sources has grown. From the outside our homes are exposed to noise from cars, trains, airplanes, etc. Noise intrudes from our neighbours and their television and stereo equipments. Also noise from spaces for mechanical services systems tends to become more important due to increasing energy saving demands. This thesis presents new analytical models for predicting the sound reduction index of single or double plate systems. In the single plate case, a theoretical and experimental analysis of the air-borne sound transmission through a single plate is presented. The plate is assumed to be excited by a diffuse sound field and the velocity distribution of the plate is derived from the Kirchoff plate equation in the frequency domain. The resulting Fourier transform is evaluated using residue calculus and the solution is verified numerically. The analytical model is valid for a wide frequency range, both below, above and at the critical frequency. Special interest is paid to the area dependency of the sound reduction index. This technique is further expanded for the double plate case by adding another plate and an intermediate layer which is modelled as a locally reacting spring. The model is valid and continuous through both the mass-spring-mass resonance and the coincidence region. The results from the analytical models show good agreement with measured results in both the single and double plate case. A simplified model is also presented for the sound reduction index of finite size floating floors. The model is valid for two elastic plates with a resilient layer in between where the bottom plate, the load-bearing slab, is assumed to be excited with a diffuse airborne sound field. The top plate and the resilient layer compose the floating floor. The problem is solved for frequencies below, between and above the critical frequencies of the plates. Above the critical frequency of the load-bearing plate, but below that of the floating slab, the main coupling between the plates will occur at the coincidence angle of the load-bearing plate. Above the critical frequency of both plates, the main transmission will occur at the angle of coincidence of each plate. As the plates will interact, the sound insulation improvement will to some extent depend on the properties of the load-bearing slab. It is shown how the sound reduction index depends on the physical parameters and the geometry of the plates. / QC 20101101

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

Thesis (doctoral)--Universität Bremen, 2005. / Includes bibliographical references (p. 113-125).