Consolequip Steering Bogie for the Société Nationale Industrielle et Minière ‘SNIM’ de la Mauritanie

2000 ◽  
Author(s):  
Varoujan Khatchadourian
Keyword(s):  
Dynamic Response ◽  
Shear Stiffness ◽  
Design Engineering ◽  
Unique Combination ◽  
Heavy Duty ◽  
Wheel Wear ◽  
Damping Characteristics ◽  
Stiffness Characteristics ◽  
Hunting Stability ◽  
Elastic Shear

Abstract This paper describes in detail the design, engineering and testing conducted for 260 self-steering bogies in response to a bid from SNIM (Société Nationale Industrielle et Minière), in Mauritania, Africa. Severe environmental conditions in Mauritania, caused by the presence of sand, contribute to accelerated wheel tread wear. This in combination with asymmetric wheel wear typically experienced with the standard three-piece bogie, results in poor wheel life. A steering bogie improves wheel life by allowing the axles to self-align, thus reducing asymmetric wheel wear occurrence. Bogie behavior is explained by comparing the stiffness characteristics of self-steering bogies and standard three-piece bogies. High bogie stiffness keeps a truck square as it travels on the track, thus improving its dynamic response on tangent track. Split type friction wedges are used together with heavy-duty suspension system to obtain high bogie shear stiffness and vertical damping characteristics. An elastic shear pad between the roller bearings and the side frame pedestal roof allows the axles to self-align in curves, giving the truck its self-steering characteristic. The truck design is unique as the standard AAR unit guide bracket construction point and angle were changed to provide the alignment for the unique combination of axle spacing and wheel diameter. It utilizes 1000 mm diameter wheels and a wheel base of 1800 mm. The Consolequip steering bogie has been engineered to improve dynamic response on tangent track. This is done by increasing bogie interaxle shear stiffness which increases the threshold of truck hunting. Stability tests with service worn wheels confirmed stability speed to exceed operating speeds used by SNIM network. Preliminary projections have estimated an improvement of up to 50% in wheel life by reducing asymmetric wheel wear and the number of times they are re-profiled.

scholarly journals The shear stiffness characteristics of four Eocene-to-Jurassic UK stiff clays

Géotechnique ◽  
2017 ◽  
Vol 67 (3) ◽  
pp. 242-259 ◽  
Author(s):  
A. Brosse ◽  
R. Hosseini Kamal ◽  
R. J. Jardine ◽  
M. R. Coop
Keyword(s):  
Shear Stiffness ◽  
Stiff Clays ◽  
Stiffness Characteristics

Analysis of Vibration Characteristics for Last Stage Blade With Friction Contact Surfaces of Steam Turbine

2011 ◽  
Author(s):  
Yutaka Yamashita ◽  
Koki Shiohata ◽  
Takeshi Kudo
Keyword(s):  
Dynamic Response ◽  
Steam Turbine ◽  
Contact Surface ◽  
Contact Forces ◽  
Analysis Method ◽  
Friction Damping ◽  
Normal Contact ◽  
Damping Characteristics ◽  
Last Stage ◽  
Contact Surfaces

Friction damping devices such as under platform dampers are installed for modern turbine blades to suppress dynamic vibrations of the blades. In order to secure the reliability of the blades, it is important to predict the dynamic response and friction damping characteristics accurately. In this present paper, the dynamic response and friction damping characteristics of a last stage blade (LSB) of a steam turbine with contact surfaces at the cover, tie-boss and blade root was investigated. Especially, it is focused on the effect of the non-uniform normal contact forces at the contact surface. To investigate the effect of non-uniform normal contact forces, an analysis method was developed. Analysis model of the LSB with contact surfaces was discretized by finite elements. Tangential forces at the contact surfaces were modeled by multi-DOF macro-slip modeling. The non-linear frequency responses of the LSB were obtained by using the harmonic balance method. Using this analysis method, the relationship between the contact surface behavior and the dynamic response was studied.

scholarly journals Investigation into the Damping and Stiffness Characteristics of an Elevator Car System

2010 ◽  
Vol 24-25 ◽  
pp. 77-82 ◽  
Author(s):  
I. Herrera ◽  
H. Su ◽  
Stefan Kaczmarczyk
Keyword(s):  
Dynamic Performance ◽  
Design Procedure ◽  
Harmonic Excitation ◽  
Experimental Procedure ◽  
System A ◽  
Damping Characteristics ◽  
Single Person ◽  
Stiffness Characteristics ◽  
Stiffness And Damping ◽  
Experimental Rig

Modelling the dynamic performance of an elevator car system represents a complex task and forms an important step in the elevator system design procedure. The need to consider the behaviour of passengers travelling in the car complicates the procedure further. This paper presents an original approach to identify the stiffness and damping characteristics of an elevator car system. A simplified model is developed and the experimental rig with a rectangular elevator platform fixed on the top of four silent blocks attached to a shaker is setup. The transmissibility measurements are carried out with a harmonic excitation applied first to a platform with no passenger load and then to the platform with one passenger within the frequency range of 1 – 20 Hz. A single person standing on the platform is employed in order to assess the passenger’s contribution to the dynamic behaviour of the elevator car system. The curve fitting technique implemented in MATLAB is used to determine the damping and stiffness coefficients both for the empty car system and the car-passenger system. Investigation on the tolerances for both parameters is carried out. An approach to simplify the experimental procedure and to reduce the number of individual tests is proposed.

A Highly Efficient and Reliable Power Scheme Using Improved Push-Pull Forward Converter for Heavy-Duty Train Applications

2016 ◽  
Vol 20 (2) ◽  
pp. 342-354 ◽  
Author(s):  
Liran Li ◽  
◽  
Zhiwu Huang ◽  
Heng Li ◽  
Xiaohui Qu ◽  
...  
Keyword(s):  
Low Voltage ◽  
Power Converter ◽  
Design Guidelines ◽  
Heavy Duty ◽  
Wheel Wear ◽  
Brake Shoe ◽  
Modeling And Control ◽  
Forward Converter ◽  
High Impedance ◽  
And Control

Electronically controlled pneumatic (ECP) brake systems have become popular in heavy-duty train applications because of their advantages, which include shorter stopping distances, improved handling, and less brake-shoe and wheel wear. In ECP brake systems, an improved power supply is required to support efficient and reliable operations. In this paper, we propose a new power converter for ECP brake systems, which is derived from a conventional push-pull converter. As opposed to conventional push-pull converters, we insert a clamping capacitor into the proposed circuit. This clamping capacitor simultaneously enables a greater number of operation modes for the proposed converter and absorbs the voltage spikes in the switch. The proposed converter is more suited for ECP brake applications that require high power, low voltage ripple, and high impedance. We theoretically analyze the proposed converter, and present the design guidelines. Further, we discuss the modeling and control aspects. We demonstrate the operations of the proposed model by performing both simulations and experiments.

scholarly journals Response of Fractionally Damped Beams with General Boundary Conditions Subjected to Moving Loads

2012 ◽  
Vol 19 (3) ◽  
pp. 333-347 ◽  
Author(s):  
R. Abu-Mallouh ◽  
I. Abu-Alshaikh ◽  
H.S. Zibdeh ◽  
Khaled Ramadan
Keyword(s):  
Dynamic Response ◽  
Boundary Conditions ◽  
Fractional Derivative ◽  
Fractional Derivatives ◽  
Initial Conditions ◽  
General Boundary ◽  
General Boundary Conditions ◽  
Damping Characteristics ◽  
The Laplace Transform ◽  
The Right

This paper presents the transverse vibration of Bernoulli-Euler homogeneous isotropic damped beams with general boundary conditions. The beams are assumed to be subjected to a load moving at a uniform velocity. The damping characteristics of the beams are described in terms of fractional derivatives of arbitrary orders. In the analysis where initial conditions are assumed to be homogeneous, the Laplace transform cooperates with the decomposition method to obtain the analytical solution of the investigated problems. Subsequently, curves are plotted to show the dynamic response of different beams under different sets of parameters including different orders of fractional derivatives. The curves reveal that the dynamic response increases as the order of fractional derivative increases. Furthermore, as the order of the fractional derivative increases the peak of the dynamic deflection shifts to the right, this yields that the smaller the order of the fractional derivative, the more oscillations the beam suffers. The results obtained in this paper closely match the results of papers in the literature review.

Nonlinear Wheelset Dynamic Response to Random Lateral Rail Irregularities

1974 ◽  
Vol 96 (4) ◽  
pp. 1168-1176 ◽  
Author(s):  
E. H. Law
Keyword(s):  
Dynamic Response ◽  
Nonlinear Equations ◽  
Equations Of Motion ◽  
Power Spectra ◽  
Railway Vehicle ◽  
Lateral Stiffness ◽  
Wheel Wear ◽  
Rail Irregularities ◽  
Nonlinear Equations Of Motion

The nonlinear equations of motion for a railway vehicle wheelset having profiled wheels and contact of the wheel flange with flexible rails are presented. The effects of spin creep and gyroscopic terms are included. The rails are considered to have random lateral irregularities which are described by prescribed power spectra. The equations of motion are integrated numerically and the effects on the dynamic response of quantities such as speed, track roughness, wheel wear, flange clearance, and lateral stiffness of the rails are investigated.

Mooring with Multicomponent Cable Systems

1980 ◽  
Vol 102 (2) ◽  
pp. 62-69 ◽  
Author(s):  
K. A. Ansari
Keyword(s):  
Dynamic Response ◽  
System Design ◽  
Mooring Line ◽  
Analysis Tool ◽  
Mooring System ◽  
Practical Application ◽  
Analysis Techniques ◽  
Anchoring System ◽  
Cable Systems ◽  
Stiffness Characteristics

Relative to the present-day need for offshore operations involving the use of moored vessels, mooring system design has become quite complex. Since a proper choice of mooring line components in the form of anchors, clump weights, chains and cables is vital for vessel station-keeping and mooring system survival, the adequacy of the mooring system under consideration must be checked out by suitable analysis techniques. This paper gives a general discussion of the various mooring line components available for use, presents an analysis tool to determine the stiffness characteristics of a multicomponent cable including the effect of line stretch, and demonstrates how these could be included in the dynamic analysis of an offshore construction vessel moored by a multileg anchoring system. The maximum limiting tension of the mooring line considered, which is a combination of anchors, clump weights, chains and cables is determined from the several breaking strengths and anchor capacities associated with the various cable configurations that can occur. Finally, in order to illustrate a practical application, the dynamic response of a moored production barge subjected to external environmental forces is examined.

Numerical Analysis of the Dynamic Flame Response and Thermo-Acoustic Stability of a Full-Annular Lean Partially-Premixed Combustor

2016 ◽  
Author(s):  
Alessandro Innocenti ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Matteo Cerutti
Keyword(s):  
Dynamic Response ◽  
Gas Turbine ◽  
Operating Conditions ◽  
System Stability ◽  
Driving Mechanism ◽  
Heavy Duty ◽  
Flame Response ◽  
Partially Premixed ◽  
Heavy Duty Gas Turbine ◽  
Acoustic Stability

A thermo-acoustic stability of a full-annular lean partially-premixed heavy-duty gas turbine combustor is carried out in the present paper. A sensitivity analysis is performed, varying the flame temperature for two operating conditions. The complex interaction between the system acoustics and the turbulent flame is studied in Ansys Fluent, using Unsteady-RANS simulations with Flamelet-Generated Manifolds combustion model. Perturbations are introduced in the system imposing a broadband excitation as inlet boundary condition. The flame response is then computed exploiting system identification techniques. The identified flame transfer functions are compared each other and the results analysed in order to give more physical insight on the coupling mechanisms responsible for the flame dynamic response. The effect of fuel mass flow fluctuations is then introduced as further driving input, describing the flame as a Multi-Input Single-Output system. Further in-depth studies are carried out on pilot flames aiming at replicating the dynamic response of the real flame and understanding the driving mechanism of thermo-acoustic instability onset as well. The obtained results are implemented into a finite element model of the combustor, realized in COMSOL Multiphysics, to analyse the system stability. Numerical model affordability has been assessed through comparisons with results from full-annular combustor experimental campaign carried out by GE Oil & Gas since the early phases of the design and development of a heavy-duty gas turbine. This allowed the discussion of the model ability to describe the stability properties of the combustor and to catch the instabilities onset as detected experimentally. Valuable indications for future design optimization were also identified thanks to the obtained results.

scholarly journals Effective elastic shear stiffness of a periodic fibrous composite with non-uniform imperfect contact between the matrix and the fibers

2014 ◽  
Vol 51 (6) ◽  
pp. 1253-1262 ◽  
Author(s):  
Juan C. López-Realpozo ◽  
Reinaldo Rodríguez-Ramos ◽  
Raúl Guinovart-Díaz ◽  
Julián Bravo-Castillero ◽  
J.A. Otero ◽  
...  
Keyword(s):  
Fibrous Composite ◽  
Shear Stiffness ◽  
Imperfect Contact ◽  
The Matrix ◽  
Elastic Shear
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