Selection of Aggregate Properties to Minimize Rutting of Heavy Duty Pavements

2009 ◽  
pp. 45-45-23 ◽  
Author(s):  
SA Cross ◽  
ER Brown
Keyword(s):  
Heavy Duty ◽  
Aggregate Properties ◽  
Selection Of

scholarly journals Optimum Selection of Variable Pitch for Chatter Suppression in Face Milling Operations

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 112 ◽  
Author(s):  
Alex Iglesias ◽  
Zoltan Dombovari ◽  
German Gonzalez ◽  
Jokin Munoa ◽  
Gabor Stepan
Keyword(s):  
Removal Rate ◽  
Face Milling ◽  
Heavy Duty ◽  
Variable Pitch ◽  
Thin Walls ◽  
Chatter Suppression ◽  
Milling Operations ◽  
Optimum Selection ◽  
Cutting Capacity ◽  
Selection Of

Cutting capacity can be seriously limited in heavy duty face milling processes due to self-excited structural vibrations. Special geometry tools and, specifically, variable pitch milling tools have been extensively used in aeronautic applications with the purpose of removing these detrimental chatter vibrations, where high frequency chatter related to slender tools or thin walls limits productivity. However, the application of this technique in heavy duty face milling operations has not been thoroughly explored. In this paper, a method for the definition of the optimum angles between inserts is presented, based on the optimum pitch angle and the stabilizability diagrams. These diagrams are obtained through the brute force (BF) iterative method, which basically consists of an iterative maximization of the stability by using the semidiscretization method. From the observed results, hints for the selection of the optimum pitch pattern and the optimum values of the angles between inserts are presented. A practical application is implemented and the cutting performance when using an optimized variable pitch tool is assessed. It is concluded that with an optimum selection of the pitch, the material removal rate can be improved up to three times. Finally, the existence of two more different stability lobe families related to the saddle-node and flip type stability losses is demonstrated.

scholarly journals Diagnostics of the technical condition and predic-tion of accident-free guaranteed operating time of heavily loaded machines gear wheels

2021 ◽  
pp. 54-61
Author(s):  
Anatoliy Gaydamaka ◽  
Yurii Muzykin ◽  
Volodymyr Klitnoi
Keyword(s):  
Least Squares Method ◽  
Limit State ◽  
Operating Time ◽  
Technical Condition ◽  
Final Decision ◽  
Heavy Duty ◽  
Gear Wheels ◽  
Scheme Selection ◽  
Operation Results ◽  
Selection Of

Problem. This article highlights the current state of diagnostics of gears on the level of accumulated fatigue damage in operation. The generalization of the known information on determination of a technical condition of separate gear wheels, especially with big modules (m> 20 mm), allows to outline prospects of development of such diagnostics of a technical condition of gear wheels directly in the course of operation. Goal. The goal of this study is to develop an algorithm for diagnosing the technical condition and forecasting a fault-free operation of the gears of heavy-duty machines. Methodology. The least squares method and the confidence interval method are used to predict accident-free guaranteed gear operation. Results. A procedure for diagnosing the technical condition of gears by measuring the hardness of the metal has been developed, which includes five main stages: selection of the device; choice of measurement scheme; selection of the number of measurements, number and relative position of measuring points; development of a design of a template for measurements; development of a device for fastening templates. When determining the accident-free guaranteed operating time on the basis of several criteria of the limit state, the final decision is made on the criterion that determines the minimum term. Originality. The method of forecasting accident-free guaranteed operating time of gears is chosen taking into account the stages of running-in and stable in linear function accumulation of damage in operation. Practical value. The use of the developed procedure for diagnosing the technical condition of the gears of gearboxes of heavy-duty machines will significantly increase the efficiency of their operation due to the transition from scheduled preventive maintenance to maintenance according to the actual technical condition.

scholarly journals Comparative Study of Powertrain Hybridization for Heavy-Duty Vehicles Equipped with Diesel and Gas Engines

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2072
Author(s):  
Ilya Kulikov ◽  
Andrey Kozlov ◽  
Alexey Terenchenko ◽  
Kirill Karpukhin
Keyword(s):  
Electric Drive ◽  
Fuel Economy ◽  
Energy Content ◽  
Storage System ◽  
Energy Storage System ◽  
Heavy Duty ◽  
Driving Cycles ◽  
Auxiliary Power ◽  
Selection Of ◽  
Heavy Duty Vehicles

This article describes a study that aimed to estimate the fuel-saving potential possessed by the hybridization of conventional powertrains intended for heavy-duty vehicles based on diesel and natural gas fueled engines. The tools used for this analysis constitute mathematical models of vehicle dynamics and the powertrain, including its components, i.e., the engine, electric drive, transmission, and energy storage system (ESS). The model of the latter, accompanied by experimental data, allowed for an analysis of employing a supercapacitor regarding the selection of its energy content and the interface between the traction electric drive and the ESS (in light of the wide voltage operating range of supercapacitors). The results revealed the influence of these factors on both the supercapacitor efficiency (during its operation within a powertrain) and the vehicle fuel economy. After implementation of the optimized ESS design within the experimentally validated vehicle model, simulations were conducted in several driving cycles. The results allowed us to compare the fuel economy provided by the hybridization for diesel and gas powertrains in different driving conditions, with different vehicle masses, taking into account the onboard auxiliary power consumption.

A TERA Based Comparison of Heavy Duty Engines and Their Artificial Design Variants for Liquified Natural Gas Service

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Matteo Maccapani ◽  
Raja S. R. Khan ◽  
Paul J. Burgmann ◽  
Giuseppina Di Lorenzo ◽  
Stephen O. T. Ogaji ◽  
...  
Keyword(s):  
Natural Gas ◽  
Risk Analysis ◽  
Value Chain ◽  
Gas Turbines ◽  
Research Collaboration ◽  
Global Solutions ◽  
Heavy Duty ◽  
Process Technology ◽  
Equipment Selection ◽  
Selection Of

The liquefaction of natural gas is an energy intensive process and accounts for a considerable portion of the costs in the liquefied natural gas (LNG) value chain. Within this, the selection of the driver for running the gas compressor is one of the most important decisions and indeed the plant may well be designed around the driver, so one can appreciate the importance of driver selection. This paper forms part of a series of papers focusing on the research collaboration between Shell Global Solutions and Cranfield University, looking at the equipment selection of gas turbines in LNG service. The paper is a broad summary of the LNG Technoeconomic and Environmental Risk Analysis (TERA) tool created for equipment selection and looks at all the important factors affecting selection, including thermodynamic performance simulation of the gas turbines, lifing of hot gas path components, risk analysis, emissions, maintenance scheduling, and economic aspects. Moreover, the paper looks at comparisons between heavy duty industrial frame engines and two artificial design variants representing potential engine uprates. The focus is to provide a quantitative and multidisciplinary approach to equipment selection. The paper is not aimed to produce absolute accurate results (e.g., in terms of engine life prediction or emissions), but useful and realistic trends for the comparison of different driver solutions. The process technology is simulated based on the Shell DMR technology and single isolated trains are simulated with two engines in each train. The final analysis is normalized per tonne of LNG produced to better compare the technologies.

scholarly journals THE PROCESS OF DESIGNING SPECIAL WHEEL CHAIR FOR PEOPLE WITH PHYSICAL DISABILITIES

2020 ◽  
Vol 20 (Special1) ◽  
pp. 192-200
Author(s):  
Mohd HO ◽  
Marzuki I ◽  
Ahmad FA ◽  
Imran A ◽  
Muhammad SA ◽  
...  
Keyword(s):  
Physical Disabilities ◽  
Field Research ◽  
Heavy Duty ◽  
User Testing ◽  
Pulley System ◽  
Design Procedures ◽  
Wheel Chair ◽  
Electrical Component ◽  
People With Physical Disabilities ◽  
Selection Of

There is a need to design and develop an affordable motorized vehicle for better mobility among physical disabilities. This study aimed is to initiate appropriate and affordable materials to develop an accessible motorized wheelchair. It includes the feasibility study of the existing used wheelchair, the system used and the characteristic of the physical disabilities symptom. Through the observation, an existing motorized wheelchair uses stainless steel as the main structure, manipulating the shelves heavy-duty accessories, electrical component, heavy-duty battery and car pulley system in which the weight accumulates approximately 100 kg. The heavyweight wheelchair cannot be folded and put inside the car. It also needs to have a special carrier to carry the wheelchair. The field research has also been conducted to evaluate the existing wheelchair system in the market with various systems used, components, and motors material used in the area of technical, usability and comfort before start to redesigning the wheelchair. The results of the study would include the background needs of the characteristic of physical disabilities. The available high-grade aluminium materials will be used to support the mobility and their relevant properties. The design will be done all the way and the specification will be used as an instrument data for the motorized vehicle. The selection of design features, documentation of design procedures and results will be used to create a P.O.C (Prove of Concept) prototype for the meant vehicle. The user will use the preliminary prototyping test and the data (result) will be used to improvise the wheelchair prototype. The second improvised prototype will undergo the second user testing in the area of reliability, stabilization of system, and ease of usage. The results expected will be observed and tested by the user to lead towards the recommendation of the motorized wheelchair design.

Research on the Efflux Angle to Emergency Escape Ramp of Mountain Roads

2011 ◽  
Vol 97-98 ◽  
pp. 257-265
Author(s):  
Bing Hong Pan ◽  
Rui Juan Liang
Keyword(s):  
Mechanical Properties ◽  
Geometric Features ◽  
Lateral Stability ◽  
Heavy Duty ◽  
Main Road ◽  
Reasonable Range ◽  
Selection Of

To resolve heavy-duty trucks side over the boxes, scraping the guardrail and other accidents when driving into the entrance of emergency escape ramp, according to studying on lateral stability of the out-of-control heavy-duty trucks and combining with their mechanical properties, this dissertation analyses the wheelpath’s geometric features when the out-of-control heavy-duty trucks rush into the emergency escape ramp from the main road, results a reasonable range to adapt the efflux angle of emergency escape ramp on our mountain expressways, and provides necessary theoretical references for the selection of the efflux angle on mountain roads.

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