S Danyluk SM Hsu and S Jahanmir

National Bureau of Standards

Abstract

It has been estimated that the effective use and advances in tribology can save the U.S. economy $18 billion dollars per year, and 40$ in the effective transfer of existing tribological expertise to practicing engineers and designers. A computerized numeric database with easy, quick access to both recommended practice as well as design codes will help to achieve this goal.

A computerized database with validated numerical data, and "best judgement values" by experts will aid in establishing tribology as an interdisciplinary science where information on lubricant chemistry, materials, mechanics, surface science, interface contact, surface topography, elastohydrodynamics, fluid mechanics, heat transfer, mechanical designs are available. Computerization will advance the quality of research as well as identify the critical linkages in tribological systems research.

The computerized tribology' information system is being developed as a self-sustaining activity with government providing the initial funding for research and prototype construction. Current data bases do not go beyond the establishment of bibliographic databases and, many technical challenges exist in data architecture, computer system software design, entry module design and data communication and standardization.

Presented at the 1987 ASME International Computers in Engineering Conference and Exhibition, August 9-13, 1987, New York, NY.

Success in this program will have significant impact on other similar programs around the world.

Introduction

The computerization of tribological data by the establishment of a self-sustaining computerized tribology information system is described. This paper outlines (a.) the planning and coordination of an international effort to standardize and disseminate computerized tribological data (b.) the implementation of a self-sustaining ongoing effort that will eventually be supported by industry and (c.) a technical plan for the design of the computer system architecture, development of standardized database formats and, the framework for the database communication and dissemination. This research represents a pioneering effort in the computer architecture of databases since this will be the first time that a technical field as complex as tribology will be computerized. This research also represents the advancement of tribology as a discipline; the computerization will promote the standardization of tribological data and practice and elevate the discipline of tribology.

Tribology is being increasingly recognized as a critical discipline that can play a key role in raising the level of U.S. competitiveness. For example, advances in tribological research can significantly reduce the present day losses due to friction and wear in the industrial, metalworking, transportation, and utilities sectors with an estimated saving of $18 billion dollars per year^'. In addition, the research results in areas such as high temperature lubricants, the friction and wear behavior of ceramic and metal-matrix composites, the development of hard surface films and, the mechanical design of components offer the promise of engineering components and systems with higher reliability, greater efficiency and longer life.

Tribology encompasses cross-disciplinary research in materials, lubricants and, component and system design and as such, the research results are published in a variety of specialized journals. Because of this diversity of data, the cross-disciplinary nature of tribology and the wide range of journals in which it is published, it is difficult for researchers and engineers to locate pertinent data that is reported in a standardized format or specialized data outside the field in which it was developed. As a result, the advances in tribology that could be incorporated into engineering practice have been slow to be realized. The centralization of tribological data will facilitate validation by tribology experts, continual updating as new research results are available, serve as a clearinghouse of tribological news or research breakthroughs, and finally provide a central point of access to research-in-progress and tribological products. These objectives require a coordinated and international effort to standardize tribology data so that the system can be easily used and disseminated.

The aim of this effort is the design of a system that is self supporting; the participants being industrial sponsors that will pay for the services of the system. The initial funding for the planning of this system and for the construction of a prototype has already begun and the technical areas of research have been identified. These include the development of the computer system architecture of the entry module, the software interface, the database format, the linkages between databases and, the communication between the system and the database users.

Background

The development of a computerized tribology information system (ACTIS) is being planned in accordance with the recommendations of the international tribology community. In the last three years, the Industrial Research InstituteConference on Tribology, The Canadian Associate Committee on Tribology^2) and, the American Society of Mechanical Engineers-Research Committee on Tribology (ASME-RCT)(3) have recommended as the highest priority the development of a computerized tribology information system. These organizations have recognized the rapid expansion and growth of tribology research and the critical need to organize, standardize and coordinate data. With the advent of user-friendly database management software^) and the proliferation of personal computers^', a computerized tribology information system is now possible^).

The ASME-RCT in conjunction with the U.S. Department of Energy-Energy Conservation and Utilization Technology Division and the National Bureau of Standards (NBS) conducted a workshop in August 1985 at NBS where 60 tribologists from U.S. and European industries and universities, U.S. national laboratories and government agencies participated in the planning of a computerized tribology information system^?). The workshop attendees discussed and evaluated the utility and the practical problems associated with the implementation of such a system and recommended that the needs of the tribological community could be met with the following six databases: Numeric, Design, Newsletter, Bibliographic, Research-in-Progress and, Product and Services Directory (these databases are described in the appendix). The primary users of such a system were identified to be tribology researchers in materials, lubricants and lubricating systems and design and applications engineers. In addition the data was also envisioned to be useful to the broader engineering community as well as new product and component developers, failure analysts and purchasing agents. The cost to develop such a system was estimated to be approximately $12 million dollars.

As a result of the workshop recommendations, the U.S. DOE-ECUT Tribology Program provided seed funding for the planning and development of a prototype system that consists of Numeric, Design and Bibliographic databases. The National Bureau of Standards has taken a lead role in directing the development of these databases and has provided the management support and a focus for this activity.

During this past year, funds have also been provided by the U.S. Air Force Wright Aeronautical Laboratories, the U.S. Army Fort Belvoir Research, Development and Engineering Center and, the American Society of Lubrication Engineers. The American Society of Mechanical Engineers and a number of industries have also provided manpower in support of this project.

Technical Challenges for the Implementation of ACTIS

The development of ACTIS requires programmatic and technical plans that incorporate input from the international tribology community. Many of the issues have never been addressed before and their resolution will require new and innovative approaches.

ACTIS will contain six databases: Numeric, Design, Bibliographic, Newsletter, Research-in-Progress, and Product and Services Directory, the design of some of these has never before been incorporated into a comprehensive computerized system. The initial technical challenge then is to structure the computer system architecture so that the user can draw on data from any one database. In addition, the interface between the databases must be constructed so that there is linkage between the databases.

Figure 1 shows the conceptual plan for the computer system architecture that will be used for ACTIS. A user can access any one database through a main menu or through an interacting interface that connects the databases. This connection must be transparent to the user. For example, a designer utilizing the Design database may require numeric data for a particular code. This data will be called-up in the proper format and units and, the user can- select a best judgement value or statistically analyze the available data as suits the purpose.

Each database, in addition, requires a unique structure. For example, the numeric database will consist of such diverse technical subjects as materials properties┬┐ lubricant and additive properties, abrasive wear and component and system design. The data with these subject areas must -be organized in standardized formats with agreed-on text so that a non-expert can utilize the data. Figures 2 and 3 show two possible examples of Materials Properties and Lubricant and Additives data formats that will be used in the Numeric database. Each item must be recorded in the proper units and contain an explanatory text and references. The computer codes that will contain this data can be quizzed according to any one of the data items and, the numeric data can be statistically analyzed. A computer system architecture that handles this type of complexity has never before been developed.

The Design database will contain a component, material and lubricant selector guide, design codes for components and systems and, design calculations. The software for many of these codes have not yet been developed and, since each code has its individual complexity, the system architecture will include a common front-end so that all the codes appear with a common menu format when the system is entered. This database will also contain complex system codes as for example a multiple bearing shaft analysis which will require numeric data in standardized units. These data must be called from the Numeric database. Also, the codes must be user-friendly and contain sufficient text so that a nonexpert may access the codes and utilize the results. Finally, the codes must be verified for accuracy and evaluated for robustness and ease of use. This includes a standard set of input and output so that the user may verify if the code is functioning properly.

The Newsletter, Research-in-Progress, Bibliographic, and Product and Services Directory, databases will also require unique computer structure. The Newsletter will eventually be an on-line news distribution system.' The individual news items must be linked to additional text that guides the user into the system. The Research-in-Progress database must be continually updated and new research results should be incorporated into the Newsletter and Bibliographic databases. The Bibliographic database also needs to be updated and.expanded as new materials or designs are developed. The Product and Services Directory will serve a critical need to the engineering community by providing the data on new products or services. This database will serve as the technology transfer link so the structure of this database must be flexible and easy to use.

The resolution of these technical issues require the input from the industrial community which form an integral part of the feedback loop between the computer architecture developers and the experts assembling the databases since industry must eventually support this system.

Methodology

The construction of ACTIS is an outgrowth of the workshop held at NBS in 1985. At that meeting, the workshop attendees committed to development of a plan that incorporates six databases. During the past year, the organizational structure of ACTIS and the technical contents of a prototype system have been developed.

ACTIS has been designed to be built in three phases with Phase I funded principally through government agencies. Figure i) shows how the system has evolved. A PC-based prototype system is being developed in Phase I; the self-contained PC disks will be available for distribution through technical societies. Funds from the sale of these discs will be used to support additional efforts related to the system. Phase II will be jointly managed by the Government Steering Committee and ACTIS, Inc. ACTIS, Inc. will be established when the proceeds from the sale of PC discs and the fund raising efforts has reached a pre-set dollar value. These monies will be set aside in a "Trust Fund" and the organization and distribution of funds from this "Trust Fund" will be similar to that already established between the Joint Committee on Powder Diffraction (JCPDS)- International Center for Diffraction Data and NBS. The proceeds of the sale of the design codes will be distributed as follows: 1 556 to the technical society responsible for distribution, 15? to the code developer, and 70? to ACTIS, Inc. During Phase II, a minicomputer gateway system will be developed; users will access this gateway through PC's linked via telephone lines. The ACTIS, Inc. will manage the system in Phase III and carry out a business and marketing strategy using the funds in the "Trust Fund".

Figure 5 shows the management structure for Phase I; ACTIS is currently being managed by a Government Steering Committee, chaired by S.M. Hsu of the National Bureau of Standards. This committee is composed of tribology managers whose organizations have contributed funds or other resources for the initial stages of this program. The Government Steering Committee is advised by an International Technical Advisory Committee chaired by E.E. Klaus of the Pennsylvania State University and an Industrial Liaison Committee chaired by C. Rowe of Mobil Corporation. The membership of these two committees dramatizes the level of commitment by the U.S. Government agencies, the industrial community, and internationally recognized tribology researchers. These individuals are contributing their time and effort to the development of ACTIS.

The program is being coordinated by a full-time technical liaison, supported through NBS and located at NBS.

Figure 6 shows the technical program plan for four years. The effort in year one has been devoted to the development of the computer system architecture and the Numeric and Design databases. These two databases are initially being incorporated in a prototype system that is contained on PC disks. In later years, the databases will be stored on a minicomputer and accessed via a communication system. In the second year, the Newsletter and Bibliographic databases will be initiated. The Newsletter database will be distributed as a hard copy as well as electronic mail. In the fourth year, the Product and Services Directory database will be assembled. The support for this database will not involve government funding. The following section expands on the present status of the first year of the development of ACTIS.

Present Status of ACTIS

The technical plan for development of the prototype system in Phase I is shown in Figure 7. The computer system architecture, designed by the Los Alamos National Laboratory and reviewed by NBS collaborators, is designed to be self-contained such that the software can be used directly with a stand-alone PC-based system and to be easy to demonstrate and market. The interface language is written in C programming for an IBM

compatible PC with 540 kbytes of random access memory, two floppy disk drives, a hard disk drive, graphics card and math coprocessor. The user interface will be window/menu driven with forms-oriented data entry.

The prototype system will contain the Numeric and Design databases; the Numeric database is being monitored by the Technical Advisory Committee and the Design database is being assembled by a Design Task Force consisting of members from technical societies, universities, and industries.

The Numeric database subject areas recommended by the Technical Advisory Committee are as follows:

a. metals and ceramic properties b. lubricant and additive properties c. lubricated friction and wear d. abrasive wear e. erosive wear f. metal cutting and machining g. rolling element bearing

The Numeric database subject areas and the contributors are listed in Table 1. Each contributor who is an expert in the listed subject area has agreed to review his topic, develop a data format and, provide "best judgement" values under a small grant. The Technical Advisory Committee will review these contributions for uniformity and completeness, and these data will be incorporated in the system.

The Design database will contain the following design codes and design calculations:

a. component selector guide b. hydrodynamic journal bearing design c. ball1 bearing design d. spur gear design e. mechanical face seals f. elastic contact stress analysis g. elasto-hydrodynamic film thickness h. failure analysis of tribological components

The Design database was recommended by the ASME/Joint Societies Design Task Force, a committee composed of members from universities, technical societies and, industrial research organizations. Table 2 lists the members of this committee and their organizations which have contributed time and effort to this project. The technical advisory committee will validate the codes for accuracy and evaluate the codes for robustness and ease of use.

The entry module for both databases will be similar; the Design database will contain a standard set of input values, variable names, designation of output destination, output formats and error handling. In addition, the Design database will contain a specialized, abbreviated numeric database specific to the design codes.

This first year of ACTIS has involved the programmatic planning and, the development of the computer system architecture and the details of the prototype system. The data format in seven subject areas in the Numeric database is scheduled to be completed in January 1988. These data will be entered into the prototype system by June 1988.

The Newsletter and Bibliographic databases will be initiated in the second year; the Newsletter database will be developed in two stages. A hard copy of the Newsletter will be designed and mailed, in addition, an electronic mail system will be instituted for on-line news. The Bibliographic database will include the currently available tribological databases; the front-end of this database will call existing databases in a transparent way to the user.

The Research-in-Progress database will be initiated in year three. The initial source of this database will be the survey conducted by the Tribology Program of NSF. The Product and Services Directory will be initiated in the fourth year from non-government funds.

The gateway system with the six databases will be completed by the end of the fourth year.

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