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This thesis involves the consideration of the reinforced concrete beam as a composite beam with incomplete interaction. The influence of bond slip and loading condition on the formation of cracks is studied analytically. / Thesis / Master of Engineering (ME)

Yes / Twelve reinforced-concrete continuous deep beams having web openings within interior shear spans were tested to failure. The main variables investigated were the opening size and the amount of inclined reinforcement around openings. An effective inclined reinforcement factor combining the influence of the amount of inclined web reinforcement and opening size is proposed and used to analyse the structural behaviour of continuous deep beams tested. It was observed that the end support reaction, diagonal crack width and load capacity of beams tested were significantly dependent on the proposed effective inclined reinforcement factor. As this factor increased, the end support reaction and increasing rate of diagonal crack width were closer to those of companion solid deep beams. In addition, a higher load capacity was exhibited by beams having an effective inclined reinforcement factor above 0.077 than the companion solid deep beam. A numerical procedure based on the upper-bound analysis of the plasticity theory was proposed to estimate the load capacity of beams tested. Comparisons between the measured and predicted load capacities showed good agreement.

no / The design of multi-storey buildings in the UK, in the past, considered steel and concrete structures in isolation. Today, designers utilize the combined properties of steel and concrete in the form of composite or hybrid structures as a more attractive efficient alternative. Designers of steel structures acknowledge that the presence of concrete slabs may be designed compositely with steel beams in order to increase both flexural strength and stiffness at virtually no extra cost, except for the headed shear studs. The use of composite construction with precast hollowcore slabs has become one of the most popular construction methods in the UK. Currently, design of composite construction is covered by BS5950, Part 3, but will soon be replaced by the new European Standard, Eurocode 4. However, design of composite construction with precast hollowcore slabs is currently outside the provisions of this new code. In this paper, an overview of the Eurocode 4 structure and its contents are first presented and some of the particular issues that affect this new form of construction will be given. Design guidance using the Eurocode methodology will also be presented.

A time-domain model-based crack diagnostic methodology using vibration data is presented. Most of the damage detection methods proposed to date are based on modal parameters and are limited by the loss of information caused by data reduction and by the implicit assumption of linearity. The use of time domain information permits the direct inclusion of the nonlinear behavior due to crack opening-closure cycles. In addition, very little information is lost, since no signal processing or parameter identification steps are involved. The proposed method is based on a continuous model for the transverse vibrations of beams consisting of partial differential equations of motion with varying coefficients to account for the presence of damage. In order to provide accurate representation of the structure's behavior over a broader frequency range, a new continuous cracked beam model including shear effects and rotatory inertia is developed using the Hu-Washizu-Barr variational method. The resulting equations of motion are discretized by a Galerkin method using local B-splines as test functions. The crack is assumed to be either fully open or fully closed, resulting in a bilinear system. The simultaneous identification of crack location and depth is performed by minimizing the norm of the differences between the numerical and experimental time responses to multiple excitations. Impact, low frequency sinusoidal and Schroeder--phased multisine inputs are investigated as potential excitation methods. The cost function to be minimized presents several local minima that are shown to be related to the length of the response records. A genetic algorithm is used to overcome the multimodal nature of the objective function. The methodology is validated through simulated identifications of several damage scenarios. The importance of the inclusion of the nonlinear behavior is addressed, and the effects of model uncertainties and measurement noise are quantified in terms of minimum identifiable crack size. / Ph. D.

Although Particle Beam Liquid Chromatography/Mass Spectrometry (PB LC/MS) has been shown to be useful for the identification and confirmation of nonvolatile and thermally labile compounds, evidence has been reported of response nonlinearity at low concentrations. Addition of a mobile phase additive to the HPLC mobile phase improves the linearity via a so-called "carrier effect.” A study has been done to characterize the physical and chemical phenomena involved in this carrier effect. A matrix of probes and additives were combined at 9 levels (2-1000ng) while Single Ion Monitoring (SIM) monitored the effectiveness of each additive on linearity and sensitivity. Next, the pH and concentration of the additive were varied for the 24 sample probes, ranging from pharmaceutical to environmental samples. Data is provided demonstrating the statistical effect on quantitative performance for each study. Analytical examples are shown. A mathematical model has been applied to account for the nonlinearity of PB LC/MS. For a given droplet distribution, reducing the concentration of the analyte results in reduced particle size. Application of a high pass filter to a particle distribution replicates response factor and signal obtained by PB LC/MS. In addition, a mathematical model representing the linear response upon addition of a nonvolatile buffer has been successfully applied. Graphs are presented showing the feasibility of this model. / Master of Science