Search Results

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.

Currently, the truck industry does not systematically address driver issues in Intelligent Vehicle-Highway System development. Because this industry is at the forefront of IVHS system and device development, it is imperative that the human factors issues are included in the research, development, design and evaluation of IVHS systems. This will minimize the risk of inadequate, unusable and unsafe devices that become a part of every truck drivers day. As IVHS technology is developed and more of these devices become available a new issue must be addressed: will the combination of these new devices overwhelm the driver and result in a reduction of safety? Could the combination of certain systems counteract each other, resulting in an unused or unusable system? History indicates these problems, and many others are definite possibilities.

Evolution in the standardization of steel sizes and chemistries has been taking place at Caterpillar over the last eight years. This has occurred through conscious optimization of several internal and external factors. The history, techniques and further potential of the project will be presented.

Over the past several years the Institute of Electrical and Electronic Engineers (IEEE) Standards Association has developed standards for the 5.9 GHz Dedicated Short Range Communications protocols, also known as Wireless Access in Vehicular Environments. These standards consist of IEEE 1609 as well as an amendment to the IEEE 802.11 standard or 802.11p. The 1609 standards were published for Trial Use and these as well as the 802.11p draft have been implemented in a variety of test beds to provide lessons learned and feedback into the standards working groups. Based on ongoing testing, the protocols display a strong capability to address the requirements of crash avoidance and transportation mobility applications. The corresponding test results provide information necessary to update the standards after the first trial phase as industry moves toward commercial implementations.

The purpose of this SAE Information Report is to provide concepts for rational selection and application of materials for Rollover Protective Structures (ROPS) and Falling Object Protective Structures (FOPS) and to provide information about the properties that should be considered in selecting and utilizing material in protective structures. While other materials could conceivably be used successfully, this report is limited to a consideration of steel with discussion on its mechanical properties and processing characteristics. Emphasis is placed on the toughness aspect (ability to resist brittle fracture) as this property is of paramount importance to structure integrity. It is emphasized that specific values for material properties have relevance to performance only in conjunction with specific design considerations such as structure size or weld joint detail and location.

The bushing "TRAC" code is intended to be a tool that will aid in the definition of the geometric environment for the test, or use, of an elastomeric bushing.

This paper illustrates the potential benefits of identifying planet gear bushing failures in military Light Armored Vehicles (LAVs) using vibration signature analysis techniques over conventional thermocouple methods. A pneumatically driven test rig was developed to measure the vibrational response of a lubricated dimpled bushing using accelerometers mounted externally to the bushing housing. Fourier-based signature analysis techniques are employed to track the wear history of the bushing liner material under steady load and steady shaft rotational speed. Vibration data collected from the accelerometers was analyzed by calculating the band power of specific frequency bands. Three separate run-to-failure tests showed a direct linear relationship between band power and bushing wear for frequency bands that may be related to the worn dimpled pattern of the bushing. The data was also shown to be a reasonable predictor of bushing wear within specified confidence bounds.

Since the Californian ZEV mandate caused a new wave of interest in the electric automotive propulsion system to sweep over the world, the question of why earlier attempts to bring the electric vehicle to the market failed is heavily debated. As to the possible causes of failure of the electric vehicle during the first two decades of this century, the consensus among automotive engineers tends to be that it was the high weight and the low energy density of the battery which prevented the electric motor from becoming the dominant automotive propulsion system. Since then, this argument goes, the situation hasn't changed very much. In this paper, based upon a recently finished doctoral dissertation on the history of early American and European electric vehicles [1], other, mainly non-technical, failure factors are suggested as being more convincing.

In the early 1990's, the Standards and Data Services Committee (SDSC) of the American National Standards Institute (ANSI) saw the need for a national standards system network that would allow users to identify and obtain the standards documents necessary for their work. From this initial concept the NSSN has grown to become a comprehensive source for standards information on the World Wide Web. This paper will briefly provide the history of the NSSN; describe the current services available; and discuss the current development direction for the service.

Engineering new technology and products challenges managers to balance design innovation and program risk. To do this, managers need methods to judge future results to avoid program and product disasters. Besides the traditional prediction tools of schedule, simulations and “iron tests”, process control standards (with measurements) can also be applied to the development programs to mitigate risks. This paper briefly discusses the theory and case history behind some new process control methods and standards currently in place at Caterpillar's Electrical & Electronics department. Process standards reviewed in this paper include process mapping, ISO9001, process controls, and process improvement models (e.g. SEI's CMMs.)

This paper gives a history of simulation of commercial vehicles, starting with the early models and progressing to today's multibody models. This is followed by a discussion of the key questions faced by simulators. Finally, the paper presents a new method to postprocess results through videoanimation.

This paper explores the history behind the use of fine filters on off-road transmissions, the evolution of coreless filter technology, and the introduction of new coreless filters suitable for high temperature powershift transmissions.

In 1946, the Allison Division of General Motors initiated heavy duty transmission operations at its headquarters in Indianapolis, Indiana. Since that time, Allison has become a world leader in the design, development, and manufacture of heavy duty automatics for the world truck and bus market. This paper traces the history of this effort and discusses key innovations and events at Allison over the past 50 years. Included are discussions starting with Allison's history, its first bus transmission in 1946, and first automatic transmission for on-highway trucks in 1954. This is followed by the development of both the second and third generation automatics and the innovations that are incorporated in these generations. The effect of these innovations is expressed in terms of customer benefits and market growth. Lastly, a view of future trends in automatic transmissions is provided.

Fatigue design has to account for the scatter of component geometry, material behavior and loading. Scatter of the first two variables is mainly due to manufacturing and material sourcing. Loading on the other hand depends decisively on operating conditions and customer usage. Loading is certainly most difficult to determine. Tests on proving ground or even long-term real time measurements are used to obtain actual load time histories. Because of the costs of measurements and safety measure, real-time measurements are used exceptionally to gain changes in the usage profile. In this paper, an attempt has been made to find the difference in the extrapolated data to the actual data. A comparison has been made between the actual road distance of 2000 km to the extrapolated data of 100 km, 500 km and 1000 km to 2000 km. The front Axle channel is taken for the study.

The history of off-road equipment manufacturing has been based on proven designs and long times between model updates. In sharp contrast with this strategy is the electronic manufacturing services (EMS) industry. The EMS industry is driven by the larger consumer product industry's continuing pressure for lower costs. Because of this, EMS tools, processes, and practices have evolved to support rapid technology and component changes. However the increasing consumer demand for features like better user-interfaces, more efficient fuel consumption, and the desire for increased operational controls in equipment have forced the off-road industry to increase the frequency of product updates to meet customers' needs. Equipment manufacturers make running changes leading to a “Learning-by-doing” development and manufacturing process. But rapid changes sometimes have an unpredictable impact on the reliability of the final product.

The presented work emphasises the method and means in the development of a load-time history to be used in design and testing of railway structures. Strains are measured on an in-service train and subsequently processed. The processing includes analysis and correction of the measured time history in order to obtain the expected distributions of peaks, troughs and ranges. The time history is extrapolated to the design life, truncated and small load cycles are omitted for the purpose of acceleration at testing. Further, the use of variable amplitude loads in design is discussed and a methodology for variable amplitude testing is proposed.

Most of the history of systems engineering has been focused on processes for engineering a single complex system. However, most large enterprises design, manufacture, operate, sell, or support not one product but multiple product lines of related but varying systems. They seek to optimize time to market, costs of development and production, leverage of intellectual assets, best use of talented human resources, overall competitiveness, overall profitability and productivity. Optimizing globally across multiple product lines does not follow from treating each system family member as an independently engineered system or product. Traditional systems engineering principles can be generalized to apply to families. This article includes a multi-year case study of the actual use of a generic model-based systems engineering methodology for families, Systematica™, across the embedded electronic systems products of one of the world's largest manufacturers of heavy equipment.

Evaluation of vehicle structural durability is one of the key requirements in design and development of today's automobiles. Computer simulations are used to estimate vehicle durability to save the cost and time required for building and testing the prototype vehicles. The objective of this work was to find the service life of automotive structures like passenger commercial vehicle (bus) and truck's cabin by calculating cumulative fatigue life for operation under actual road conditions. Stresses in the bus and cabin are derived by means of performing finite element analysis using inertia relief method. Multi body dynamics simulation software ADAMS was used to obtain the load history at the bus and cabin mount locations - using measured load data as input. Strain based fatigue life analysis was carried out in MSC-Fatigue using static stresses from Nastran and extracted force histories from ADAMS. The estimated fatigue life was compared with the physical test results.

To validate the integrity of a commercial vehicle's exhaust system's structural design is a challenging job. An integrated approach to use both simulation/modeling and hardware testing must be employed to reduce product development cost. In addition to the considerations of the geometry and configuration specs of 70-90 parts and joints as well as material's thermal and mechanical property data in model development, representative loading must be used. For base excitation type of loading, such as the one experienced by the vehicle's exhaust system, one must decide whether to conduct the time domain transient analysis or frequency domain random vibration analysis. Although both methods are well known, few discussions can be found in the literature regarding their effective use in the framework of product design and development. Based on our study, the random vibration method should be used first for identifying high stress locations in the system and for design optimization.

The number of IV/HS Commercial Vehicle Operations (CVO) systems may be much larger than what might be expected. When compared to the coverage given to consumer IV/HS demonstrations, the lack of awareness of commercial systems is understandable. In fact, there are hundreds of installations of commercial systems world-wide. While the goals of each application vary with the user, these systems are generically used for Computer-Aided-Dispatching (CAD) and remote access to host computer databases. The system users include police and fire departments, trucking companies, taxi companies, internodal ports, and utilities. These organizations are experiencing the benefits of increased safety, better efficiency, and improved service. CVO systems fundamentally change the way the mobile work force relates to the organization and, in turn, affect the way the organization functions. A brief history of CVO installations, a review of design issues, and user justification will be presented.