The Research of the Application of Reactive Powder Concrete Wind Barriers of High Speed Railway Bridges

2011 ◽  
Vol 255-260 ◽  
pp. 886-890
Author(s):  
Xiao Lv Lu ◽  
Ri Gao
Keyword(s):  
Traffic Safety ◽  
High Speed ◽  
Model Building ◽  
3D Models ◽  
Reactive Powder Concrete ◽  
Railway Bridges ◽  
Calculation Results ◽  
The Stability ◽  
Reactive Powder ◽  
Analysis Platform

In this paper, completes the selection of preliminary Reactive Powder Concrete (RPC) wind barriers, and on the basis of the theories of the computational fluid dynamics ( CFD), relying on the model-building and analysis platform of FLUENT, 3D models of trains under crosswind with and without wind barriers are built. From the calculation results of the pressure distribution,path lines and aerodynamic forces of model trains under 3D turbulence flows ,the stability of trains under crosswind is analysed ,and the effects of the wind barriers on traffic safety of trains are discussed.The results show that rationa1 design of the wind barriers is able to improve the traffic safety of trains.

Tests on Mechanical Properties and Anti-Penetration Performance of Steel-Fiber Reactive Powder Concrete

2013 ◽  
Vol 671-674 ◽  
pp. 1761-1765
Author(s):  
Yong Liu ◽  
Chun Ming Song ◽  
Song Lin Yue
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Reactive Powder Concrete ◽  
Calculation Results ◽  
Reactive Powder ◽  
Penetration Tests

In order to get mechanical properties ,some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. And a group of tests on RPC with 5% steel-fiber under penetration were also conducted to validate the performance to impact. The penetration tests are carried out by the semi-AP projectiles with the diameter of 57 mm and earth penetrators with the diameter of 80 mm, and velocities of the two kinds of projectiles are 300～600 m/s and 800～900 m/s, respectively. By contrast between the experimental data and the calculation results of C30 reinforced concrete by using experiential formula under penetration, it shows that the resistance of steel-fiber RPC to penetration is 3 times as that of general C30 reinforced concrete.

Design and Behavior of RPC Slab Track

2014 ◽  
Vol 587-589 ◽  
pp. 1100-1105
Author(s):  
Jian Yang ◽  
Jin Sheng Wang ◽  
Xin Peng
Keyword(s):  
Material Properties ◽  
High Speed ◽  
Optimization Design ◽  
Reactive Powder Concrete ◽  
High Speed Railway ◽  
Slab Track ◽  
Existing Problems ◽  
Ballastless Track ◽  
Reactive Powder ◽  
And Behavior

Reactive Powder Concrete is proposed to be used in the ballastless track for its excellent material properties due to existing problems of high speed railway ballastless track. Three different unit types of RPC frame slab track were proposed through optimization design and the mechanical behavior of these frame slab track was analyzed. The results show that the RPC slab track meet the requirements of bearing capacity, the suggested type of RPC slab track is a frame slab with increased thickness because of its higher techno-economic advantages.

scholarly journals NON-LINEAR ANALYSIS OF REACTIVE POWDER CONCRETE (RPC) DEEP BEAMS WITH OPENINGS STRENGTHENED BY CFRP

2019 ◽  
Vol 11 (2) ◽  
pp. 176-196
Author(s):  
Asst. Prof .Dr. Ragheed Fatehi Makki ◽  
Asst.Prof.Dr.Ali Talib Jassem ◽  
Hayder Abd Al-latef Jassem
Keyword(s):  
Experimental Results ◽  
Reactive Powder Concrete ◽  
Analysis Software ◽  
Deep Beams ◽  
Element Analysis ◽  
Ansys Analysis ◽  
The Finite Element Analysis ◽  
Calculation Results ◽  
Parametric Studies ◽  
Reactive Powder

This paper mainly uses ANSYS V.15 , the finite element analysis software, to make nonlinear analysis of reactive powder concrete  deep beams . The models simulating the test process were established, the calculation results of ANSYS are compared with the experimental results. Data of eight RPC deep beams tested by researchers were used for comparison with ANSYS models .Furthermore three parametric studies were carried out by changing the size of opening , location of openings and CFRP systems configuration . The comparison shows that ANSYS analysis results are similar to experimental results (the  maximum difference in the ultimate load  was less than 7.5 %), which indicates ANSYS analysis software can be used to simulate the mechanical property of reactive powder concrete structures.

Aeroelastic modelling and stability analysis of tiltrotor aircraft in conversion flight

2018 ◽  
Vol 122 (1256) ◽  
pp. 1606-1629 ◽  
Author(s):  
Z. Li ◽  
P. Xia
Keyword(s):  
High Speed ◽  
Aeroelastic Stability ◽  
Rotor Wake ◽  
Motion Modes ◽  
Bending Mode ◽  
Calculation Results ◽  
Unsteady Effect ◽  
Unsteady Inflow ◽  
The Stability ◽  
Tiltrotor Aircraft

ABSTRACTIn conversion flight, the aeroelastic modelling of tiltrotor aircraft needs to consider the unsteady effect of the rotor wake bending due to the rotor tilting. In this paper, the unsteady models of the rotor wake bending and dynamic inflow have been introduced into the aeroelastic modelling of the tiltrotor aircraft in conversion flight by using Hamilton’s generalized principle. The method for solving the aeroelastic stability of tiltrotor aircraft in conversion flight has been established by using the small perturbation theory and the Floquet theory. The influences of unsteady dynamic inflow on trim control inputs and aeroelastic stability of a tiltrotor aircraft in conversion flight were calculated and analysed. The calculation results show that the required collective pitch increases with the pylon tilting forward and the unsteady inflow is trimmed primarily by the lateral cyclic pitch of the rotor. The wake bending unsteady dynamic inflow can obviously reduce the stability of the flapping modes of the rotor, and have no obvious influence on the lag modes of the rotor and the motion modes of the wing. The instability of tiltrotor occurs in the chordwise bending mode of the wing when the pylon tilts to a certain angle in high speed forward flight.

Design of Simple-Supported Reactive Powder Concrete Railway Bridge with Span of 32m

2010 ◽  
Vol 163-167 ◽  
pp. 904-907
Author(s):  
Zhi Gang Yan ◽  
Wen Yu Ji ◽  
Ming Zhe An
Keyword(s):  
High Strength ◽  
Bridge Engineering ◽  
Reactive Powder Concrete ◽  
Railway Bridge ◽  
Railway Bridges ◽  
Safety Coefficient ◽  
High Durability ◽  
Mixing Proportion ◽  
Reactive Powder ◽  
T Beam

Reactive Powder Concrete (RPC) is a new kind of engineering material with high strength, high elastic modulus and high durability. In order to satisfy the low-height requirement, RPC is adopted to design the railway bridge. One simple-supported RPC T-beam with span of 32m is designed and applied in railway bridge engineering. The height of the beam is 1.8m and the height to span ratio is 1/17.8. It is supper low-height beam for railway bridges. The parameters of material properties, mixing proportion, section size and prestressed steel strand cable arrangement of the RPC T-beam are presented. The load bearing capacity, the deflection and the crack resistance safety coefficient are calculated and the results can satisfy the requirements of the code. It is useful for the design and application of RPC in structure engineering.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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