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To get a sequence retainable rainflow cycle counting algorithm for fatigue analysis, an alternate equivalent explanation to rainflow cycle counting is introduced, based on which an iterative rainflow counting algorithm is proposed. The algorithm decomposes any given load-time history with more than one crest into three sub-histories by two troughs; each sub-history with more than one crest is iteratively decomposed into three shorter sub-histories, till each sub-history obtained contains only one single or no crest. Every sub-history that contains a single crest corresponds to a local closed (full) cycle. The mean load and alternate load component of the local cycle are calculated in parallel with the iterative procedure.

Interactive simulation of machines and machine concepts has been successfully used to research new designs and methods for harvesting forests. Uses of interactive simulation to better relate forestry, engineering design, and economics for the development of forestry products and practices are illustrated. Past interactive simulations of forestry operations are reviewed and current research activities are discussed.

Microplastic deformation associated with rough surface and dents are found to generate tensile residual stress, which can be a source of surface fatigue. Both pre-existing hoop stress and friction-induced lateral normal stress parallel to surface are found to have an effect on the plastic strains and tensile residual stress. This finding can possibly explain many reported experimental observations that in rolling/sliding contact, the slower surface is more susceptible to surface fatigue than the faster mating surface. Micropitting probability and wear volume loss can be formulated based on Mode I crack growth process using the tensile residual stress as the fatigue criterion.

In this study, a six litres displacement, commercial vehicle engine that meets the EURO-5 regulation was used to evaluate the durability and performance deterioration of the SCR system mounted on a heavy-duty diesel vehicle. ESC and ETC modes were used for emission test. Characteristics of emissions by SCR catalyst deterioration were investigated using mileage vehicles of 0 km, 120,000 km, and 360,000 km. EDS (Energy Dispersive X-Ray Spectroscopy) analysis on PM filters and CT scan to catalyst substrate were carried out in order to investigate the status of catalyst by each mileage. As a result, it was found that NOX, slipped NH3 as well as PM due to unreacted ammonia and urea increased as the mileage of the catalyst increased.

Effective requirements elicitation and management is a common need in supplier-OEM relationships, and continues to play a vital role in all aspects of the product development lifecycle. While traditional methods address the business goals for requirements and provide guidance in ensuring the accuracy of the “Descriptive-Prescriptive-Explanatory” outputs for requirements gathering and documentation, engineering organizations continue to encounter challenges with respect to capturing and communicating change, accommodating the addition of relevant design details and efficient propagation to inform development. These challenges become more difficult to overcome in mechatronic systems, which combine mechanical systems with integrated software. As software development can produce an overwhelming volume of information that requires accurate tracking and proliferation, it cannot be effectively managed using traditional hardware-centric systems.

The heavy truck industry, during the 1990's faces increasing numbers of electronically controlled component systems; two factors have been recognized and are being addressed by SAE and The Maintenance Council (TMC) of the ATA: (a) the on-board electronic based component modules must communicate in an efficient manner; (b) off-board diagnostic tools, most likely computerized, must be developed and offered to the industry to insure efficient maintenance of these on-board components. This paper provides the background and the current status of the effort, primarily chartered by TMC, to recommend a more standard or universal environment for diagnostic technology.

The migration of electronically controlled components to the heavy truck necessitates equally as sophisticated computers in the service area to diagnose and isolate the faults identified by the component and posted via the SAE Recommended data link (currently J1708). To date our industry's component manufacturers have taken a direction of developing unique “manufacturer specific” computerized diagnostic technologies. This paper: (a) outlines an alternative uniform technical environment, referred to as the Universal Diagnostic Platform for the Heavy Truck Industry, (b) covers the background leading up to this recommendation, (c) states the current status of industry wide activity related to this topic and (d) makes recommendations to the industry.

A new oval test track will be designed, constructed and operated in a manner that will successfully pull-together representatives from virtually all of the key interests in dealing with the challenging issues of highway pavement and truck durability. With construction scheduled to begin in the Summer of 1998 and completion scheduled for late 1998 or early 1999, the mission and commitment for this venture is to pull-together the people from several state DOTs, respective universities, and, of vital importance, the truck manufacturing industry. Results from these tests, over a period of a few years, will provide answers that not only greatly improve performance of hot mix asphalt pavements in all state DOTs, but also efficiently and productively address issues of durability and wear performance of medium / heavy duty trucks and key components.

A new Artificial Intelligence (AI) “Expert System” software technology has been developed which shows real promise as the core platform of the Decision Support System for Truck Repair. The “Expert system” consists of a Model Based reasoning mechanism, and a Rule Based shell along with an on-line documentation and graphics capability. This technology combines the development speed and accuracy of Model Based technology, the precision of Rule Based expert systems along with the ease-of-use associated with a “Hypertext” information system.

The purpose of this paper is three fold: to serve as a tutorial for engineers new to the field of drivetrain; to function as a reference manual for those who wish to retrieve some information on a topic they have not visited for some time; and to show the direction that four-wheel-drive technology should be taking. A brief history of four-wheel-drive is followed by some examples showing the broad range of four-wheel-drive vehicles in use today. All components of typical systems are discussed in some detail. The mechanics, function, purpose, and logic of different types of systems are described, as are their advantages and disadvantages. Handling characteristics and traction capabilities of some different systems are analyzed. A majority of the vehicles produced today have systems that simply lock all drive axles together when in four-wheel-drive mode. This limits their use to off-road or extremely slippery conditions.

Low crew productivity and extension of service intervals past design limits are the two major reasons so many heavy equipment PM programs are ineffectual. ALPM, or Assembly Line Preventive Maintenance is an innovative system for equipment servicing, providing management scheduling tools and the necessary controls. The system has a successful track record in a number of severe applications.

This paper will review the design and operating characteristics of a new class of materials handling equipment, the automated monorail system (AMS), its components and controls. System characteristics such as speeds of up to 600 feet per minute, low noise levels, production surge adaptability, multi-spur and multi-plane layouts, load queuing, and integration with higher level systems will be discussed and their applicability to air cargo handling noted. An AMS installation, recently put into service for an air transport-related application by a major U.S. airline will also be described.

The technical growth of American agriculture will be determined by the pressures of the society within which that agriculture is rooted. To predict and influence the direction of growth, it is necessary to examine the history of the society and to extrapolate its pattern of development. These patterns are studied and translated into mechanical requirements and the necessary developments in philosophy and technique of control are discussed. It is shown that principles of closed-loop systems--servos--must be applied and that the key development will be the measuring elements (sensors). The requirements in the several areas of agriculture are examined and three specific examples of feasible developments are described: The first is one requiring simple on-off control. The second utilizes a numerical data-processing system and control.

This SAE Standard includes complete general and dimensional specifications for those types of pipe, filler, and drain plugs (shown in Figures 1 to 6 and Tables 1 to 4) commonly used in automotive and related industrial applications.

This standard includes complete general and dimensional specifications for those types of pipe, filler, and drain plugs (shown in Figs. 1-6 and Tables 2-4) commonly used in automotive and related industrial applications.

This SAE Standard includes complete general and dimensional specifications for those types of pipe, filler, and drain plugs (shown in Figures 1 to 6 and Tables 1 to 4) commonly used in automotive and related industrial applications.

The present work has the objective to quantify and evaluate abrasive wear resistance of a hard coating. It is obtained by weld deposition of an iron based alloy containing Cr and Nb as carbide forming elements, and to compare it to wear resistance of a heat treated SAE 5160 steel, normally used for agricultural equipment. Wear resistance was determined from two body and a three body abrasion tests using pin abrasion test equipment and a rubber wheel abrasion test, respectively.

Determining pre-impact acceleration and braking performance values is an important aspect of reconstructing collisions. Collision analysts may have to rely upon performance testing of an exemplar vehicle for reliable data to use in traffic collision reconstruction cases. These performance characteristics are well documented for many vehicle classes, but are limited when discussing urban transit style buses. The constant stop and go urban driving conditions in which they operate constantly challenge the vehicle components. Because of the heavy weights and operating conditions, auxiliary braking systems are often installed to prolong the life of the service brakes. A series of idle acceleration, maximum acceleration, and maximum braking tests were conducted using urban transit style buses that are currently in-service in a large metropolitan area. The initial braking target speed for these braking tests was 64 kph (40 mph).

Power Take Off Shaft Shields — a Resumé of design history and development within the European agricultural industry, with reference to the governing regulations applicable, and the legal requirements of such a safety device.

Accident reconstructionists rarely have complete data with which to determine vehicle speed, and so the true value must be bracketed within a range. Previous work has shown the effect of friction uncertainty in determining speed from tire marks left by a vehicle in yaw. The goal of the current study was to assess improvements in the accuracy of vehicle speed estimated from yaw marks using progressively more scene and vehicle information. Data for this analysis came from staged S-turn maneuvers that in some cases led to rollover of sport utility vehicles. Initial speeds were first calculated using the critical curve speed (CCS) formula on the yaw marks from the first portion of the S-maneuver. Then computer simulations were performed with progressively more input data: i) the complete tire marks from the whole S-maneuver, ii) measured vehicle mass, iii) measured suspension stiffness and damping, and iv) measured steering history.