Yes / Recycled aggregate concrete filled stainless steel tube (RAC-FSST) is a new type of composite member combining the advantage of stainless steel and RAC. In this paper, a total of twenty-four RAC-FSST stub columns were tested under axial load, considering the influences of coarse recycled aggregate (CRA) content, steel ratios and compressive strengths of RAC. The obtained results, including the failure patterns, responses of axial load vs. deformation, stress states of external stainless steel tube and inner RAC and confinement effects, were systematically analyzed. Results indicated that all specimens presented good ductility and high residual strengths after reaching the maximum axial load. The elastic stiffness of RAC-FSSTs obviously declined with the increasing CRA content, while the strain at the ultimate load was larger. The inclusion of CRA could advance the occurrence of the confinement and lead to lower confining stress. Based on the experimental results, an analytical model with consideration of confinement action was developed to predict the axial response of RAC-FSST stub columns. Besides, the current design provisions for the normal CFST and RAC-FST members were employed to evaluate their applicability to RAC-FSSTs. In general, the design rules EN 1994-1-1:2004, GB 50936-2014 and T/CECS 625-2019 gave a conservative and relatively accurate prediction on ultimate strength of RAC-FSST stub columns. / This work was supported by the National Natural Science Foundation.

No / This paper presents the behaviour and design of axially loaded concrete filled stainless steel circular and square hollow sections. The experimental investigation was Conducted using different concrete cube strengths varied from 30 to 100 MPa. The column strengths and load-axial shortening curves were evaluated. The study is limited to cross-section capacity and has not been validated at member level. Comparisons of the tests results together with other available results from the literature have been made with existing design methods for composite carbon steel sections-Eurocode 4 and ACI. It was found that existing design guidance for carbon steel may generally be safely applied to concrete filled stainless steel tubes. though it tends to be over-conservative. A continuous strength method is proposed and it is found to provide the most accurate and consistent prediction of the axial capacity of the composite concrete filled stainless steel hollow sections due largely to the more precise assessment of the contribution of the stainless steel tube to the composite resistance.

<p> Two phase flow induced vibrations is a field that has many inherent modelling difficulties, making research in the area challenging. In order to study the problem more closely, a two phase flow loop using Freon 11 had been designed and commissioned at McMaster University. The initial design required some modifications to make the loop as "user friendly" as possible. The final result meets this desired capability. </p> <p> The loop was designed so that research into vibrations in tube bundles could be carried out. A test section had been designed to facilitate this task. However, this design also required modifications. Additionally, new vibration monitoring instrumentation making use of light was developed to avoid the detrimental effects of Freon 11. The introduction of these items has resulted in a complete facility for the purpose of studying two phase flow induced vibrations. Preliminary experiments revealed a problem relating to tube tuning. Generally, the results are promising and some interesting new phenomena were observed as well. </p> / Thesis / Master of Engineering (ME)

<p> An investigation of the technique of obtaining the wall shear stress in a two-phase flow, by measuring the mass transfer coefficient at the wall with the electrochemical method, has been completed.</p> <p> The experiments involved the measurement of flow rates, pressure drops, void fractions and mass transfer coefficients, for a cocurrent upwards gas-liquid flow in a vertical tube, 13 mm in diameter. The liquid phase was an electrolyte consisting of 1.0 to 3.0 molar sodium hydroxide, and 0.005 to 0.010 equimolar potassium ferricyanide and potassium ferrocyanide. The gas phase was nitrogen. The flow regimes studied were slug, churn and annular.</p> <p> Emphasis is placed on the measurements obtained with the electrochemical method. Its application, advantages and disadvantages are detailed. A series of single-phase experiments were performed to explore the characteristics of the method and to serve as benchmarks for the two-phase experiments.</p> <p> The space-time-averaged values of the mass transfer coefficient were found to give the wall shear stresses to an accuracy of ±20%. Frequency analysis of the local fluctuating values indicate that measurements of the local mass transfer coefficient can be used for flow regime identification.</p> <p> The theoretical flow regime map of Dukler and Taitel successfully predicted the flow regimes. The correlations of Griffith and Wallis, and Lockhart and Martinelli as modified by Davis, predicted the pressure drops and void fractions to an accuracy ±15% when applied to the appropriate flow regimes. As a further exercise, the force interactions between the phases, referred to as the interfacial shear terms, were calculated from both the measured and predicted void fractions and pressure drops.</p> / Thesis / Master of Engineering (MEngr)

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13579号 / 論医博第2301号 / 新制||医||1069(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 古川 壽亮, 教授 大鶴 繁, 教授 平井 豊博 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

In the modern building industry wood as a building material has been looked on as one of the solutions to lower the environmentally impact of the building industry. Building types that normally have been reserved for concrete and steel are today being built with wood as main load bearing component. However, the structural robustness of high-rise wood building has been questioned. The concern relates to wood’s brittle failure-mode and therefore the capacity of wood buildings to withstand catastrophic events where a loadbearing structural part its removed from the construction. To counteract a brittle failure mode in wood and create a ductile failure mode that allows alternative load paths, ductile steel connectors are seen as a solution. With inspiration from the concrete and steel industry, catenary action is brought forward as the most efficient method to create an alternative load path in high-rise wood buildings. To create catenary action, a tube connector that allows excessive deformation with increasing strength was believed to have sufficient capacity. A test method for testing tube connector capacity in a catenary event was developed with a main focus on tube capacity and forces created on the surrounding structure in a catastrophic event. To achieve this, a long stroke reversed 4-point bending test was formed and testing of traditional fasteners and the tube connector was conducted. Test result from catenary capacity testing showed low to no capacity for traditional fastening methods, however, traditional fastening method created arcing action in the beginning of the test cycles. The traditional fasteners showed a consistency in failure mode with arching and wood crushing before connection failure in form of screw withdrawal. Tube connectors had low to no consistency in failure modes, but higher consistency in capacity. Failure mode regarding tubes consisted of steel failure in tube and wood failure in the test specimen. In general, the tubes connector showed promising capacity and ductility to create alternative load paths with the help of catenary action. The project has shown that some design development for the tube connector and lager scale testing are needed to completely understand tube connector capacity and failure mode.

<p>Polymer based multifunctional material systems (MFMS) have gained increasing attention in the past two decades. The addition of nanofillers and nanoparticles allows for modification of physical properties as well as the discovery of new features. Multifunctionalization of composites allows us to “do more with less”. For example, electrically conductive additives can eliminate the need for sensors through self-sensing principles, shape morphing matrices can reduce the need for actuators, and the inclusion of fire-resistant constituents can reduce flammability in stringent fire protection measures. With added capabilities, the applications of multifunctional composites extends beyond the aerospace and automotive industries to healthcare, infrastructure, electronics, among others, and optics.</p> <p><br></p> <p>The current state of the art is largely focused on single-filler composites or multifiller composites with complementary attributes. For example, carbon nanotubes (CNTs) when mixed with graphene produces higher conductivity than can be achieved via modification with either CNTs or graphene alone. The majority of investigations conducted in this domain have fillers selected with the aim of imparting a singular property. Much less has been done in the area of multifiller and multifunctional polymer matrix composites (PMCs) which can exhibit multiple properties. Consequently, this work seeks to contribute towards the field of synergistic functional composites. That is, a multifiller composite material system comprised of differently functional fillers. This approach has potential to yield smart material systems that outperform single-filler or single-functionality materials through the discovery of novel synergistic coupling between the differently functional phases.</p> <p><br></p> <p>In light of the preceding motivation, this work presents the results on the experimental electromagnetic and mechanical characterization of multi-walled carbon nanotubes (MWCNTs) + carbon-coated iron nanoparticle (CCFeNP)-modified polymers. Carbon nanotubes with their electrical properties and iron nanoparticles with their magnetic attributes present potential for synergistic electromagnetic interactions in a well-percolated network. We report on the electro-magnetic properties of MWCNT + CCFeNP/epoxy composites including DC and AC conductivity, dielectric permittivity, magnetic permeability, and piezoresistance as a function of varying relative MWCNT and CCFeNP concentrations. The results are in a large part linked to the manufacturing process described herein. This work seeks to establish the foundations of synergistic functional filler combinations that could lead to new multifunctional capabilities in the future.</p>

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To better understand how platelets behave when exposed to high shear stress, computational fluid dynamic (CFD) models for single-layer (uniform and constant) viscosity flow and two-layer (two distinct regions of different viscosities) viscosity flow were developed. The single-layer model, which represents common standard practice, did not predict the pressure drop correctly; the error produced from using the single-layer model was approximately 95%. However, the two-layer model produced results that were within 6% of the experimental results. Experimental results used to validate CFD models were obtained from data gathered by researchers at University Medical Center (UMC) in Jackson, MS. Using Fluent 6.2, simulations were performed that showed the characteristics of blood flow in a long stenosis. The beginning of the development of a blood damage model was also investigated. This thesis could provide researchers with information that will eventually allow the prediction of platelet activation and hemolysis.

No description available.