The degradation of bridge edge beam systems in Sweden entailed the study of new alternativedesigns, which may become more optimal from a life-cycle perspective than the currenttypical solution used (concrete integrated). Subsequently, a U-shaped steel edge beamproposed by the consulting engineering group Ramböll was considered by the SwedishTransport Administration for its use in a real bridge project. This thesis follows theimplementation of this alternative in a bridge project.The goals of the thesis are to study the development of the U-shaped steel edge beam solutionin the case study, and to identify the key factors behind it. The case study consists of a roadframe bridge where a heavily damaged bridge edge beam system is going to be replaced.For the structural design of the solution, a static linear analysis of a vehicle collision has beencarried out with the help of Finite Element Modelling and current codes. The report shows themodelling of the design solution throughout different development phases in the project. Thecommercial software used has been LUSAS.As an outcome of the project, four models have been designed and analysed, two of themdeveloped by the author as proposed solutions. The factors behind the different changes in thedesign have been identified as: (1) structural resistance, (2) constructability and (3) the use ofstainless steel. Moreover, the connection between the steel edge beam and the concrete slabhas been the main critical part for the structural resistance. Finally, the current preliminarymodel at the moment this thesis is written, which was proposed in the project meetings, meetsthe requirements from a structural point of view.

No description available.

A method for acquiring and analyzing ultrasonic wavefields to characterize scattering from defects is described. A laser vibrometer and XY scanner are used to record high resolution wavefield data for angle-beam waves propagating in both a defect-free plate and a plate containing crack-like defects emanating from a through-hole. The properties of angle-beam wave propagation are first studied, which include wave generation mechanisms, propagation trajectories, and apparent phase velocities on the measurement surface. Scattering from a defect of interest is then analyzed by subtracting wavefields recorded before and after introduction of the defect. Wavefield subtraction is very sensitive to unavoidable spatial misalignment, which must be corrected prior to subtraction. Two methods for aligning wavefield data sets prior to subtraction are described and their performance is assessed. Several methods for characterizing scattering, including radial energy plots and scattering patterns, are described and used to quantify scattering from the introduced defects. Finally, efficacy of the scattering characterization methods is discussed and recommendations are made for future work.

published_or_final_version / Physics / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Physics / Master / Master of Philosophy

<p>In April 2007 we contacted Lennart Augustsson at Designpartners AB in Västerås. He came up with the idea to investigate and evaluate their construction of a interaction beam, CSB-beam. CSB is short for Connector Interaction beam. The beam is based on a horizontal C-profile of high-tensile steel and in the bottom of the profile are vertical flat bar welded so called block connectors. These block anchorsare also made of hightensilesteel. Their task is to create collaboration between the steel and the concrete.</p><p>The dimensioning of the block connectors is done according to the Swedish standard SSENV199411.The purpose of this study is to evaluate and control the formula used for the dimensioning which is found in SS-ENV 1994-1-1.There has been two main parts of this exam work. Part 1: Theoretical preliminary investigations,consisting of calculations and literature studies of block anchors. Part 2: Practical testloads of four prefabricatedCSB-beams.The results of the two parts were thencompared to see if theory corresponded to reality.</p><p>The result shows that the comparison of the formula in Swedish standard, SS-ENV 1994-1-1 can be used for dimensioning of block connectors in interaction beams.</p>

No description available.

No description available.

A study of the application of single-mode fiber optics to the multiple-beam interferometric recombination problem is presented. In the laboratory, the fibers have been used in wide bandwidth, two-arm, Mach-Zehnder test interferometers as well as a 5-telescope imaging interferometer connected to an all-fiber beam combiner. Based upon these experiments and some theoretical studies it is shown that fiber optics and fiber optic components such as directional couplers provide an excellent alternative to conventional optics such as mirrors, beamsplitters, and relay lenses. The equations describing the measurement of the complex degree of coherence in an interferometer with a single-mode fiber in each arm are derived. The equations reveal an important feature of the fibers: they filter phase fluctuations due to aberrations and turbulence at the input and convert them to intensity fluctuations at the output. This leads to a simplification of the calibration of measured visibilities. The coupling efficiency of light which has passed through a turbulent atmosphere is also studied as a function of fiber parameters and turbulence conditions for both image motion stabilized and non-stabilized cases. For the former case, coupling efficiency remains greater than 50% as long as telescope diameter is no larger than the turbulence coherence length. Beam combination architectures using arrays of directional couplers are fully discussed. Arrays accommodating up to 20 input beams are presented. The arrays require only N detector pixels for N input beams. A scheme of temporal multiplexing of the phase of each beam is used to identify individual fringe pairs. One possible scheme allows wide bandwidths even for large numbers of beams. A 5-telescope interferometer has been constructed and connected to an all-fiber beam combiner. Two extended objects were observed and reconstructed using standard radio astronomy VLBI software. The interferometer and beam combiner had good thermal and polarization stability and high throughput. Reconstructed images had dynamic ranges of about 50.

No description available.