Designs, Application and Performances of Asphalt/Bituminous Trackbeds in European, Asian, and African Countries

Author(s):  
D. Ramirez Cardona ◽  
H. Di Benedetto ◽  
C. Sauzeat ◽  
N. Calon ◽  
J. G. Rose

International rail authorities in several countries, primarily in Western Europe and Asia, have been actively involved with the development and application of asphalt trackbeds for more than 40 years. In this paper, representative activities and standards for trackbeds in countries involved with significant asphalt trackbed design and construction are described. The most common identified use of this technique consists of building asphalt subballast layers as a (partial) replacement for unbound granular material (UGM) subballast. This has been primarily associated with the construction of new high-speed lines (HSL), where the used asphalt mix is similar to those used for highway base courses. Most countries specify a layered design for the track support layers. This involves setting specific standards for individual layer thickness and bearing capacity depending on traffic characteristics. Some other identified uses include asphalt slab tracks and even sleeperless and ballastless track systems where the rail is embedded in an asphalt slab. The presented use cases in this paper account for the advantages and important considerations in relation to the use of asphalt in layered track designs. Even though some countries have adopted asphalt layers as a standard component of their track systems, more information is needed to develop a rational and optimized design method and maintenance protocols of asphalt subballast layers; thus, the importance of the data collected from instrumented track sections and information introduced in this paper.

Author(s):  
Ki-Sang Song ◽  
Arun K. Somani

From the 1994 CAIS Conference: The Information Industry in Transition McGill University, Montreal, Quebec. May 25 - 27, 1994.Broadband integrated services digital network (B-ISDN) based on the asynchronous transmission mode (ATM) is becoming reality to provide high speed, multi bit rate multimedia communications. Multimedia communication network has to support voice, video and data traffics that have different traffic characteristics, delay sensitive or loss sensitive features have to be accounted for designing high speed multimedia information networks. In this paper, we formulate the network design problem by considering the multimedia communication requirements. A high speed multimedia information network design alogrithm is developed using a stochastic optimization method to find good solutions which meet the Quality of Service (QoS) requirement of each traffic class with minimum cost.


Author(s):  
N. SATHEESHKANNA

Waste generated from industries and from various places around us not only contains rubber or plastics but contains lot many harmful pollutants whichare hazardous if disposed continuously in open and leftto degrade in our environment.Our project aims to study properties of different materials which may help in utilising the waste as well as improve the quality of roads and make them efficient, stable, durable and long lasting. Some of the materials that we have studied and considered to be tested in the partial replacement of bitumen are PMB and CRMB.


2009 ◽  
Vol 626-627 ◽  
pp. 693-698
Author(s):  
Yong Yong Zhu ◽  
S.Y. Gao

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.


2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.


2005 ◽  
Author(s):  
Vincent G. Chapin ◽  
Romaric Neyhousser ◽  
Stephane Jamme ◽  
Guillaume Dulliand ◽  
Patrick Chassaing

In this paper we propose a rational viscous Computational Fluid Dynamics (CFD) methodology applied to sailing yacht rig aerodynamic design and analysis. After an outlook of present challenges in high speed sailing, we emphasized the necessity of innovation and CFD to conceive, validate and optimize new aero-hydrodynamic concepts. Then, we present our CFD methodology through CAD, mesh generation, numerical and physical modelling choices, and their validation on typical rig configurations through wind-tunnel test comparisons. The methodology defined, we illustrate the relevance and wide potential of advanced numerical tools to investigate sailing yacht rig design questions like the relation between sail camber, propulsive force and aerodynamic finesse, and like the mast-mainsail non linear interaction. Through these examples, it is shown how sailing yacht rig improvements may be drawn by using viscous CFD based on Reynolds Averaged Navier-Stokes equations (RANS). Then the extensive use of viscous CFD, rather than wind-tunnel tests on scale models, for the evaluation or ranking of improved designs with increased time savings. Viscous CFD methodology is used on a preliminary study of the complex and largely unknown Yves Parlier Hydraplaneur double rig. We show how it is possible to increase our understanding of his flow physics with strong sail interactions, and we hope this methodology will open new roads toward optimized design. Throughout the paper, the necessary comparison between CFD and wind-tunnel test will be presented to focus on limitations and drawbacks of viscous CFD tools, and to address future improvements.


Author(s):  
Zhengsheng Chen ◽  
Minxiu Kong

To obtain excellent comprehensive performances of the planar parallel manipulator for the high-speed application, an integrated optimal design method, which integrated dimensional synthesis, motors/reducers selection, and control parameters tuning, is proposed, and the 3RRR parallel manipulator was taken as the example. The kinematic and dynamic performances of condition number, velocity index, acceleration capability, and low-order frequency are taken into accounts for the dimensional synthesis. Then, to match motors/reducers parameters and keep an economical cost, the constraint equations and the parameters library are built, and the cost is chosen as one of the optimization objectives. Also, to get high tracking accuracy, the dynamic forward plus proportional–derivative control scheme is introduced, and the tracking error is chosen as one of the optimization objectives. Hence, the optimization model including dimensional synthesis, motors/reducers selection and controller parameters tuning is established, which is solved by the genetic algorithm II (NSGA-II). The result shows that comprehensive performances can be effectively promoted through the proposed integrated optimal design, and the prototype was constructed according to the Pareto-optimal front.


Author(s):  
Olena Komchatnykh ◽  
Svitlana Petrovska ◽  
Nataliia Redko

The article considers modern condition and development perspectives of transport at whole and the transport infrastructure of Ukraine. The basis of the country transport complex makes up its infrastructure, it joins manufacturing, users, suppliers and partners. Developed infrastructure affects not only effective and timely delivery of the products, but provides for decreased transport expenses. The beneficial geographical position of Ukraine, crossing the main transit ways between Europe and Asia, presence of active Black Sea ports, developed network of railroads, car roads and pipelines throughout the latitudinal and meridian directions create all predispositions for the transport branch development. The studies of the Ukrainian transport infrastructure and transport condition during last years evidence about non-stable dynamics, which is mainly related to economical and geopolitical crisis in the country as well as the COVID 19 consequences. Analysis of the freight transport by transport kinds shows increased volumes of car transport with decreased railway transport. The rise of the car transport share is connected to its advantages: mobility, possibility of delivery exactly to the destination, high speed of delivery, flexibility of the route choice, wide range of the shipment as well as provision of logistic services by cars. Exacerbation in the East has considerably decreased number of contracts between Ukrainian shipping companies and international partners related to the international transportation. First of all, the situation provides for decreased transportation volumes on the territory of Ukraine. The level of transport services to economic system and population of Ukraine is significantly lower than that one in the developed countries of the world. According to the car road characteristics, Ukraine has long been behind not only the countries of Western Europe, but many post-Soviet countries. A necessary condition of the effective development and managing crisis in the transport branch, particularly that caused by the COVID 19 pandemics, is development and modernizing transport infrastructure of Ukraine according to the modern technological requirements. This will provide for uniform development of all regions of Ukraine, improved population life quality, development of trade and tourism as well as creation of new economic opportunities by attracting foreign investment.


Author(s):  
Jialong Zhang ◽  
Jianguo Yan ◽  
Pu Zhang ◽  
Xiaoqiao Qi ◽  
Maolong Lü

Aiming at the high-speed flight of the UAVs cooperative formation, when a single UAV has occurred, need to exit the formation flight and be close or super close to form of the formation quickly. A fast close cooperative formation controller design method is proposed to make up for low the fighting robustness, and be shortcomings of timeliness poorly and analyze the dynamic characteristic of UAV formation flight. Taking the external factors known into consideration, setting up for the longitude maneuver of nonlinear thrust vector and unsteady aerodynamic model, according to the formation velocity, flat tail rudder angle and thrust vector and pitch angle velocity for corresponding input commend signals for the controller to research the dynamic characteristic of UAV formation flight. Meanwhile, the formation flight distance error is the convergence to a fixed value, and the stability of the cooperative formation flight is good. The simulation of results show that the controller can effectively improve the speed of the close or super close to formation, and maintain the stability of the formation flight, which provides a method of the close or super close formation flight controller design.


Sign in / Sign up

Export Citation Format

Share Document