KNOWLEDGE MANAGEMENT THROUGH BIM IN CONSTRUCTION SUPPLY CHAINS

ABSTRACT Collaborative working is the key driver for delivering projects in construction industry. In construction supply chains where there is huge knowledge and information flow between the contractors, subcontractors, suppliers and distributors, it is essential to create a collaborative environment during the projects from the bidding phase to the delivery to client. There are some key virtual collaborative tools which have been started to be utilized in major civil engineering projects. The recent concept Building Information modeling (BIM) has been utilized in some major and prestigious construction projects where architects, structural engineers, suppliers, contractors and sub-contractors can work within a three dimensional platform to achieve certain tasks as design, planning, resource allocation, logistics planning, clash detection, coordination and production of design drawings. This paper first explains the recent trends in construction supply chain management, knowledge management and Building Information Modeling. Then, it discusses the integration of Building Information Modeling into construction supply chains for improving information and knowledge management practices throughout the lifecycle of the project which is called as Building Knowledge Model (BKM)

The role of a thermally sprayed CuNiIn underlayer in the durability of a dry-film lubricant system in fretting: a phenomenological model

Dry film lubricant coatings (DFL) are employed to reduce friction and damage in highly loaded contacts. Metallic underlayers, e.g. CuNiIn, can be beneficial however, there is no detailed explanation of the mechanism. This work investigates the effect of CuNiIn on fretting of a MoS2-based DFL in a cylinder-on-flat contact with a fretting amplitude of 300 µm. Two test types were run: 1. DFL without CuNiIn; 2. DFL on the cylindrical sample and DFL with CuNiIn underlayer on the flat sample. The CuNiIn increased the system’s durability. A phenomenological model highlighting the important low friction and highly wear resistant interfacial material is developed. The increased durability is ascribed to the high roughness of the CuNiIn onto which the DFL was deposited

The Measurement and Prediction of Gaseous Hydrocarbon Fuel AutoIgnition Delay Time at Realistic Gas Turbine Operating Conditions,” ASME Paper

ABSTRACT Auto-ignition delay time measurements have been attempted for a variety of gaseous fuels on a flow rig at gas turbine relevant operating conditions. The residence time of the flow rig test section was approximately 175 ms. A chemical kinetic model has been used in Senkin, one of the applications within the Chemkin package, to predict the auto-ignition delay time measured in the experiment. The model assumes that chemistry is the limiting factor in the prediction and makes no account of the fluid dynamic properties of the experiment. Auto-ignition delay time events were successfully recorded for ethylene at approximately 16 bar, 850K and at equivalence ratios between 2.6 and 3.3. Methane, natural gas and ethylene (0.5 < φ < 2.5) failed to auto-ignite within the test section. Model predictions were found to agree with the ethylene measurements, although improved qualification of the experimental boundary conditions is required in order to better understand the dependence of auto-ignition delay on the physical characteristics of the flow rig. The chemical kinetic model used in this study was compared with existing 'low temperature' measurements and correlations for methane and natural gas and was found to be in good agreement

A METHODOLOGY TO PREDICTING TOTAL DAMPING OF AXIAL COMPRESSOR SHROUDED STATOR VANES

ABSTRACT The main objective of this paper is to evaluate the capability of existing numerical tools to predict the total damping Q values of axial core compressor shrouded stator vanes with a view to use them in the forced response simulations. Here, the aerodynamic damping is calculated for a wide range of vane vibration modes and nodal diameters (inter-blade-phase angles) using a CFD based aeroelasticity program. The mechanical friction damping of vane vibration modes is computed by using a multi-harmonic balance forced response code. These calculations take into account the effects of normal contact forces, friction coefficients, contact stiffness and excitation (forcing) loads. A pragmatic methodology has been developed to calculate the aerodynamic and mechanical friction damping values and hence predicting total Q values of stator vanes. Sensitivity studies are performed to assess the effects of mass flow and interblade-phase angles on aerodynamic damping. Moreover, the analyses allowed to identify the modeshapes associated with either high aerodynamic or mechanical damping or both. The numerical results are correlated with experimentally measured total Q values from strain gauge engine tests. This work shows that the current numerical tools have the capability to predict not only the aerodynamic forcing but also aerodynamic and mechanical friction damping values. Therefore, the analysis tools and methodologies close the stator vane forced response prediction capability loop. It means the vane force responses can be predicted as measured from strain gauge engine tests. This constitutes an important step in the development of axial compressors test-tosimulations, as more efforts are being placed towards the development of whole engines test-to-simulations

Apparatus and method for electric spark peening of gas turbine components

Peening provides compression of component (6, 46, 56) surfaces in order to create residual surface compressions to resist crack propagation in components such as aerofoils. Previously peening techniques have had problems with respect to achieving adequate treatment depths, speed of treatment and with respect to effectiveness. By the present method arrangement an electrical conductor (1, 41, 51) in the form of a wire is subject to electrical pulses to cause evaporation and subsequent breakdown with high power ultrasound (HPU) propagation in a volume of dielectric fluid towards a component and so peening. The electrical conductor (1, 41, 51) ensures that there is limited possibility of electrical discharge to the component (6, 46, 51) surface whilst the positioning of the wire (1, 41, 51) relative to the surface can be adjusted to achieve best effect particularly if reflector (5) devices are utilised to concentrate (HPU) pulse presentation to the component (6, 46, 56). Furthermore, the component (6, 46, 56) can be surface treated in order to provide protection from potentially damaging emissions from evaporation and electrical discharge to the wire (1, 41, 51)

On the basis of experience ... built in product reliability

Paper from the Reliability and Maintainability Symposium, held Orlando (US) 29-31 Jan 1991Available from British Library Document Supply Centre- DSC:8019.3153(RR-PNR--90932) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Titanium MMCs key option for jet compressor design

Paper produced by materials engineers at Rolls-Royce UK for the journal Metallurgia no 361 December 1998Available from British Library Document Supply Centre-DSC:8019.322(92823) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

The jet engine

Reprinted 1996 with revisionsAvailable from British Library Document Supply Centre-DSC:98/09412 / BLDSC - British Library Document Supply CentreSIGLE5. ed.GBUnited Kingdo

Electrical distribution networks

Safe operation of electrical power distribution systems necessitates consideration of the fault level in terms of the potential for electrical current flow upon an earth or other fault within the electrical power distribution system. Previously, electrical power systems have been analysed to provide theoretical fault levels values for different zones of an electrical power distribution system based upon a worse case scenario. However, existing electrical loads will in practice provide a more adaptable and higher fault level. By monitoring and identifying an I-V characteristic upon switching electrical load in practical operation an actual default level at particular nodes in a power distribution system is determinable . In such circumstances decisions with regard to the connectablilty of further electrical generators or loads at particular parts and zones of an electrical power distribution system can be quantified by reference to the actual fault level rather than the theoretical worse case scenario level and therefore avoid unnecessary upgrading of transmission equipment or denying access to the electrical power system