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The fatigue performance of fillet-welded transverse attachments was compared for several procedure variants for both FCAW and SAW on ½ in. steel plates. Measurements of weld toe shape on adjacent pieces of weld indicated that smoother weld toes, as evidenced by larger weld toe radius, were correlated to improved fatigue performance for both processes. Fatigue tests conducted on 59 and 109 ksi yield strength plates did not show an effect of plate strength. Weld procedures designed to provide smooth toes, such as reduced parameter FCAW beads at horizontal weld toes and flat position FCAW at higher heat inputs, were shown to provide fatigue performances near post-weld improved fillets.

An important emerging technical area is computer-based modeling of the various manufacturing processes that are used in many diverse industries. These models are used to optimize manufacturing techniques to reduce fabrication costs and improve the service performance. One manufacturing process important in steel fabrication is welding. It can be a useful tool to aid in reducing fabrication costs and service durability by optimizing the weld process and is the subject of this paper.

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.)

As new information-age technologies are developed and applied by the Earthmoving Industry, standards are increasing in importance. The keys to long-term competitiveness in today's global marketplace are products of better quality, produced at lower prices, delivered in record time. Manufacturers are constantly being urged to produce better products cheaper, faster and at a higher quality than ever before. In fact, measuring quality has become the benchmark for many products. A company must have, to survive and prosper, an in-depth quality system; one that will meet and exceed the demands of customers. The International Standards Organization (ISO) has developed standards by such a quality system can be developed. These standards help guide the companies, who become certified against them, to increasingly higher levels of quality. Smaller manufacturers need to pursue this certification but cannot do it alone.

This paper shows how U.S. companies use global standards to overcome technical trade barriers and increase existing or create new trade opportunities in the global marketplace. The paper provides case study illustrations of how companies have used global standards to challenge national standards as being restrictive trade barriers; provide business opportunities by unifying technical requirements, thereby unifying markets; enhance production by producing and marketing the same product globally; and gain access to new markets that are emerging as the result of rapidly changing political, social, and economic conditions.

Standards are as old as civilization itself. The human race recognized the need for and developed standards as a voluntary means of communicating with each other as well as exchanging goods and services. In essence, standards are a means of documenting established and accepted practices. Standards define the state-of-the-art for civilization.

Environmentally acceptable hydraulic fluids are increasingly specified for use in hydraulic equipment working in environmentally sensitive areas. This paper describes the research methodology that was used to develop a high performance synthetic, environmentally acceptable hydraulic fluid. Product development consisted of: (1) setting the standards for environmental acceptability, (2) screening base fluids and additives for technical performance and minimal impact on the environment, (3) designing a formulation to meet these targets and (4) field experience. Test results demonstrating the high performance and low environmental impact of the new fluid are discussed. A key challenge when formulating an environmentally acceptable hydraulic fluid is to achieve satisfactory oxidation stability. The absence of a suitable oxidation stability test, which can differentiate between environmentally acceptable fluids and correlate with field performance, has been an issue for several years.

Natural synthetic esters are nowadays often applied as lubricants for their advantageous characteristics such as good biodegradability, low toxicity and the fact that they enable safe operation under very low and high temperatures. There is a wide range of applications in which the natural synthetic esters are used for their good biodegradability characteristics. Currently, a number of investigations are done towards oxidation stability of the natural synthetic esters. The methods of assessing the oxidation stability, benchmarking results and the outcome of a study on the effect of anti-oxidants in natural synthetic esters are decribed.

The hydraulic equipment for vehicles and in particular for off road vehicles is most prominent in the construction and earth moving industry. Oil spillages due to severe damages have initiated major environmental concerns in the past decades. Therefore Biofluids (Bf) have been introduced to the market in order to substitute conventional hydraulic fluids. Despite their environmental benefits there is still ongoing discussion about their overall performance in modern hydraulic equipment. This paper will describe the evaluation of a new fluid generation capable of both, high hydraulic performance as well as essentially less impact to the environment. This investigation includes not only intensive lab testing but also new hydraulic bench test procedures with original equipment components.

The use of environmental friendly lubricants is driven by the emergence of regulations appearing in many countries. The absence of water toxicity is of prime importance. To meet the stringent toxicity requirements, it is important to minimize the amount of additives which are potentially toxic. Base stocks of stable fatty chemicals were selected because the inherent properties closely matched the fluid properties required. This would necessitate the use of a minimum amount of additives. Particular attention has been devoted to the following : low temperature stability, proper viscosity, elastomers swelling, resistance to oxidation and parking brake friction. Complex neopolyol esters based on blends of linear saturated fatty acids are good candidates since they closely match the requirements of hydraulic fluids meeting the ecolabel specification. Comparisons with unsaturated derivatives and synthetic petrochemical esters base oils show their advantages.

Systems today are designed to be more flexible than ever before. This increasing demand has made electronically controlled systems more popular and brought into being a formal field called Mechatronics. The science of mechatronics uses mechanical, electrical, electronic, and computer science concepts in a single machine or system[1,6,8]. The key of mechatronics is that all of these areas are combined in the design stage. By using the ideas of mechatronics, more flexible and efficient machines can be produced. Electronically controlled systems are currently replacing the previous mechanically controlled systems[2,3,5].

The demand for increased performance of heavy earthmoving equipment has spurred the development of computer control for machinery using fluid power systems. Application of standard automatic control components to these systems provides the opportunity to implement advanced control approaches that reduce the operator workload and improve performance. In this work, closed-loop control is applied to the joints of a typical three-link digging device. Because the changing configuration of the device greatly changes the dynamic characteristics, an adaptive control algorithm is introduced to modify the control parameters to maintain consistent performance of the implement.

This paper presents an analytical study of the directional response of an articulated tractor/semi-trailer vehicle with steered rear tractor and trailer wheels. The steering input to the rear tractor wheels was a function of the steering input to the front wheels while the steering input to the semi-trailer wheels was either a function of the steering input to the tractor front wheels or a function of the relative articulation angle between the tractor and the semi-trailer. Computer simulation results show that the multi-wheel steering system could be useful in improving both the stability and followability of the articulated tractor/semi-trailer combinations.

The aspects of real engineering surfaces are discussed with regard to their three-dimensional nature. A review of potential uses of surface finish measurement methods is discussed for characterization of functional surfaces. Using an optical-based system and a set of specific measurement procedures, two functional surfaces with different roughness were analyzed to illustrate a typical surface topography evaluation. A simple sliding test was then utilized to show that a special finish produced by a proprietary finishing process can provide improved performance, as measured by wear differences, frictional properties and operating temperature of the system. A special surface treatment was then evaluated in conjunction with the special finish in order to enhance its functional load support. Simple sliding test results indicates a potential new engineered surface for improving tribological contact performance.

For biodegradable fluids as well as for mineral oils there is a need for fluid care to protect components and fluid against wear and degradation. Fluid care has to be taken already during the project and design phase to make sure that the system layout is suitable and that damages during the start up phase are minimized. Good clean up filtration, continuous online filtration and dewatering are essential especially when esters are in service. Valves are available to minimize water ingression and dewatering units are on the market to reach these goals.

By-pass filtering may achieve significant contamination control,but it has many disadvantages in terms of cost, maintenance and the need for a complete new system including a by-pass filter case and the lines and fittings. In contrast, a hybrid filtering system is constructed with a filter element that allows the filter paper media to share the filtration of oil with a high-efficiency media from the return line, assuring a high level of contamination control in a hydraulic system. Because the hybrid filter can be constructed in the same overall configuration as the existing filter elements, no further system change is required to make the conversion. The author discusses the effects of hybrid and by-pass filters on contamination control in each and field tests. The adverse effects of biodegradable hydraulic oil on filter strength and life and how to counter these problems will also be addressed.

Control strategies - the long term rules used in production planing and control - for highly integrated and flexible manufacturing systems in most cases are specialized in specific and usually constant production programs. Therefore, changes in the production program require adaptations in those single or combined control strategies. To keep the system optimal, there is a need for more than just analytical mathematical methods, whose limits are quickly crossed because of their complex correlations. An effective device for the development of optimal control strategies connected with an advantageous system structure is the focused Experiment Planning. It combines static analysis and calculations with dynamic simulations in order to develop alternatives for improvement of control strategies and the system structure in a repetitive process.

Legislation is forcing the introduction of biodegradable lubricants onto the earthmoving industry. It is the responsibility of both manufacturers and users to protect the environment whilst maintaining the highest engineering standards. The use of biodegradable oils is important, but is only part of the solution. A comprehensive approach is required which goes beyond the simple, but normally adopted method, of replacing a mineral oil with a biodegradable alternative. An Environmentally Friendly Lubricants Policy is required which increases the benefits for both the user and the environment. A combination of biodegradable oil, specialist off-line filtration and a monitoring program is the key to this policy. Cardev International in association with Panolin AG has successfully implemented this policy in the demanding German market for over 10 years, and it has enabled hydraulic machinery to run over 56,000 hrs without oil change, and over 12,000hrs so far in an earthmoving machine.

Environmental aspects will have a major influence on the application of hydraulics in mobile systems in the near future. With the use of environmentally friendly fluids, these aspects can be fulfilled in a convenient way. Nevertheless there are differences between the well known mineral based oils and environmentally friendly fluids based on synthetic esters which represent a new mainly unknown fluid type. For a trouble free usage of these fluids in hydraulic systems, a founded knowledge of the fluid's properties and its interaction with hydraulic components is a basic requirment. For this purpose an application based testing of these fluids is essential.