11 Articles Published

1. PERFORMANCE EVALUATION OF COMPOSITE FIBRE INCORPORATED IN A SLAG BASED CONCRETE MATRIX

Authors: J.VIKRAM

Abstract: Researchers focused on the study of mechanical behavior of fibre reinforced concrete in a detailed manner. Recent studies were made concentrating on the long term durability properties of the fibre reinforced concrete. The synergistic effect of fibre concrete which consists of two or more fibres shows a correspondingly better performance than single fibre addition. The present study focused on the drying shrinkage and effect on the compressive property due to freeze and thaw cycle. Two types of fibres such as steel and polypropylene fibres were used and a slag based concrete matrix is designed. Long term performance of this slag based hybrid fibre concrete depends on the types, size and dosage of fibre added to the concrete matrix. The test results show a significant variation for different mixes of concrete

Keywords: slag, steel, polypropylene, synergy, shrinkage.

Pages: 1 - 3 | DOI: 10.15224/978-1-63248-105-4-20

2. STRENGTHENING STEEL I-BEAM WITH CONCRETE FLANGE

Authors: M.RABIE , S.ZAKY

Abstract: Strengthening and rehabilitation of structures is a major concern for researchers in the civil engineering community in recent years due to the aging of these structures and the need for effective methods of strengthening. Concrete slab can be used for strengthening existing steel beams, In this research, the behavior of composite beams was studied. An experimental program was carried out to test fourteen simply supported composite beams and a Steel I-beam without any concrete slabs. The composite beams were divided into three groups to investigate the strengthening of steel I-beam with a concrete flange with variable slab thickness, slab width and variable position of top steel I-beam flange to the concrete slab. A valuable conclusion help structural engineer in design of composite sections is gained.

Keywords: Strengthening, Concrete Slab, Steel I-beam, Shear Connectors, Composite Section.

Pages: 4 - 8 | DOI: 10.15224/978-1-63248-105-4-21

3. STAGNATION POINT FLOW, HEAT AND MASS TRANSFER OVER A NONLINEAR STRETCHING SHEET WITHSUCTION/INJECTION

Authors: B. SHANKAR , CH. ACHI REDDY

Abstract: The present paper is to investigate the combined effects of the heat and mass transfer on the unsteady two-dimensional boundary layer flow over a nonlinear stretching sheet in the presence of Stagnation point and Suction/ Injection.The governing nonlinear partial differential equations have been reduced to the coupled nonlinear ordinary differential equations by the similarity transformations. The resulting equations are solved numerically by using Keller box method. The velocity, temperature and concentration distributions are discussed numerically and presented through graphs.

Keywords: Boundary layer flow; nonlinearstretching sheet; Stagnation point; Suction/Injection, Magneto hydrodynamics; Casson fluid.

Pages: 9 - 13 | DOI: 10.15224/978-1-63248-105-4-22

4. CURRENT INJECTION VORTEX PROMOTER FOR HEAT TRANSFER ENHANCEMENT IN A MAGNETOHYDRODYNAMIC DUCT FLOW

Authors: AHMAD H. A. HAMID , GREGORY J. SHEARD , WISAM K. HUSSAM

Abstract: The quest for cleaner, cheaper and reliable energy has motivated the development of magnetic confinement fusion reactor technology as a possible means of harnessing the energy produced by nuclear fusion for power generation. However, the magnetohydrodynamic effects act to reduce the thermal-hydraulic performance of the duct flows within the cooling blankets. The present paper reports the investigation of the duct flow with current injection as a vortex promoter for the enhancement of the convection heat transfer. The results indicate a maximum enhancement of approximately 70% over the duct flow without current injection for the highest current amplitude investigated. The competing effects of the Lorentz force and Hartmann damping result in a non-monotonic trend of Nusselt number with respect to friction parameter, while increasing Reynolds number results in a monotonic increase of Nusselt number.

Keywords: MHD, quasi-2-d, heat transfer, vortex promoter

Pages: 14 - 18 | DOI: 10.15224/978-1-63248-105-4-23

5. EVALUATION OF SEISMIC POUNDING BETWEEN ADJACENT BUILDINGS

Authors: MOHAMED ABDEL-MOOTY , MOHAMED RAAFAT , NASSER ZAKI AHMED

Abstract: Insufficient separation distance between adjacent buildings may lead to their pounding resulting in damage or failure during strong earthquakes. Accordingly, most of the design codes specify a minimum separation or gap distance between adjacent buildings to prevent this pounding phenomenon. This research studies the seismic pounding between adjacent reinforced concrete buildings under various ground motions. It also investigates the factors affecting pounding and proposes a technique to mitigate it. Buildings are modeled as two-dimensional frames to idealize the adjacent buildings. The total of 10 different cases of adjacent frames with different height combinations. Nonlinear time history analysis is utilized using finite element computer program ETABS. Real earthquake records are scaled and used to simulate ground motion. Gap element is used to model pounding between buildings. The effect of variation of some design parameters on seismic pounding is investigated. Different parameters

Keywords: structural pounding, dynamic analysis, poudning mitigation.

Pages: 19 - 23 | DOI: 10.15224/978-1-63248-105-4-24

6. DYNAMIC BEHAVIOR OF A FULL-SCALE WIND TURBINE TOWER UNDER SEISMIC LOADING

Authors: BOSHRA ABOUL-ANEN ELTALY , GHADA N. SAUDI , MOSTAFA MAHMOUD ABO EL-KHIER

Abstract: This paper presents the dynamic investigation of an existing wind turbine tower. Both experimental and numerical analyses were performed to assess the structural response of the tower under seismic load. Field ambient vibration test was applied to identify the actual dynamic properties experimentally. A vibration based finite element model was built in ANSYS to conduct the seismic response analysis. The tower shown to survive moderate earthquakes as it is located in Zafarana wind farm in Egypt, a zone lies by the red sea known for its historical seismic activity.

Keywords: Wind turbine tower, modal analysis, finite element model, seismic response analysis.

Pages: 24 - 30 | DOI: 10.15224/978-1-63248-105-4-25

7. NUMERICAL SIMULATION OF SODIUM DROPLET COMBUSTION

Authors: TADASHI WATANABE

Abstract: The combustion of sodium droplet is simulated numerically. The flow fields in and around the droplet are obtained by solving the Navier-Stokes equations and the energy conservation equations. The reaction rate for the pre-ignition stage combustion is modeled using a kinetics based model, while that for the vapor phase after ignition is based on the mass transfer rate of oxygen. The droplet motion with temperature variation is shown, and compared with the existing experimental data, Reasonable agreement is shown between the simulated and the experimental results.

Keywords: sodium droplet, combustion, numerical simulation

Pages: 31 - 34 | DOI: 10.15224/978-1-63248-105-4-26

8. EXPERIMENTAL STUDY OF RESIDUAL DISPLACEMENTS OF DOUBLE CONCAVE FRICTION-PENDULUM ISOLATION SYSTEMS RESIDUAL DISPLACEMENTS OF FRICTION PENDULUM ISOLATION SYSTEMS

Authors: ANTONIO DI CESARE , DOMENICO NIGRO , FELICE CARLO PONZO , GIANMARCO LECCESE

Abstract: After an earthquake, non-negligible residual displacements can occur if the isolation system does not possess a good restoring capability. In this paper the residual displacement of friction pendulum isolation systems is investigated through an extensive experimental campaign of controlled-displacement and seismic input experiments, both under uni-directional motion. A sequence of natural earthquakes was applied in three different lubrication conditions of sliding surfaces, corresponding to High, Medium and Low Friction. In order to improve current design method of sliding isolation systems, a simple equation for the estimation of the maximum expected residual displacements is proposed and compared with the experimental results.

Keywords: Seismic isolation, Double concave friction pendulum, Friction coefficient, Residual displacements, Shake table testing

Pages: 35 - 39 | DOI: 10.15224/978-1-63248-105-4-27

9. EFFECT OF YIELDING CORE LENGTH ON CYCLIC BEHAVIOUR OF BUCKLING RESTRAINED BRACES

Authors: SATISH KUMAR S R

Abstract: Buckling Restrained Braces (BRBs) have been found to perform better than conventional braces in resisting cyclic lateral loads due to earthquakes. The tendency of a brace to undergo global buckling is resisted by a sleeve tube and concrete in between. The bond between the core and concrete is broken to ensure that only the core gets loaded. This also decouples the strength from the stiffness and it is possible to vary them independent of each other. The paper describes the cyclic tests on two BRBs of identical strength but slightly different stiffness and concludes that much work needs to be done to evaluate the optimum values for a particular structure.

Keywords: Buckling restrained braces, Reduced core length

Pages: 40 - 42 | DOI: 10.15224/978-1-63248-105-4-28

10. EXPERIMENTAL STUDY ON THE CHARACTERISTICS OF ECO-FRIENDLY DEICERS UTILIZING CALCIUM-BASED INDUSTRIAL BY-PRODUCTS

Authors: BYUNG JAE LEE , HYUNG SEOK HEO , SEUNG LYONG LEE

Abstract: Due to the report of incidences of damage caused by chloride deicers in recent years, the need for eco-friendly deicers has increased. However, it is necessary to enhance the quality and economic feasibility. The present study derived the optimal mix of eco-friendly deicers utilizing industrial by-products and compared their performance with those of existing chloride deicers. The test results showed that the eco-friendly deicer had better performance in terms of freezing point and in ice melting tests than calcium chloride-based deicers. The eco-friendly deicer displayed little corrosion in the steel corrosion test. In the snow melting performance evaluation, liquid eco-friendly deicers demonstrated a better performance in initial snow melting than powder calcium chloride-based deicers, verifying their applicability to real sites.

Keywords: Snowmelt, Calcium chloride, By-product

Pages: 43 - 46 | DOI: 10.15224/978-1-63248-105-4-29

11. RELIABILITY DESIGN OF RESIDENTIAL-SIZED REFRIGERATORS SUBJECTED TO REPETITIVE RANDOM VIBRATION LOADS DURING TRANSPORTATION

Authors: SEONG-WOO WOO

Abstract: New designed residential-sized refrigerators subjected to repetitive random vibrations can be damaged during transportation. The damage consists of fracturing of the tubes between the compressor and condenser and tearing of the compressor rubber mounts. As the reliability quantitative (RQ) test specifications, parametric accelerated life testing (ALT) through sample inspections and corrective action plans was used to identify the key control parameters for the connecting tubes and compressor rubber mounts. The shape of failures in refrigerators found experimentally was identical to those of the failed samples in field. The connecting tube fractures resulted from the problematic shape of the compressor rubber mount. To correct these problems, the mounts and connecting tubes were redesigned. The refrigerators with targeted B1 life were expected to survive without failure during rail transport. Parametric ALTs were effective in identifying the missing design parameters of mechanical system

Keywords: Reliability, Design, Residential-Sized, Refrigerators, Repetitive, Random

Pages: 47 - 52 | DOI: 10.15224/978-1-63248-105-4-50