Institute for Systems Research Technical Reports

Permanent URI for this collectionhttp://hdl.handle.net/1903/4376

This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.

Browse

Now showing 1 - 7 of 7

Chemo-Mechanical Effects on the Efficiency of Machining Ceramics
(1992) Zhang, G.M.; Hwang, Tsu-Wei; Anand, Davinder K.; ISR
This paper presents an experimental study of the turning of a ceramic material - aluminum oxide (A12O3). Emphasis is given to gain a comprehensive understanding of the cutting mechanism. This study explores the utilization of cutting fluids with chemical additives to develop a novel machining process. The machining tests were performed on a CNC lathe. Polycrystalling diamond compact tools were used. The cutting force during machining was measured using an instrumented tool holder as a dynamometer. The surface finish was inspected using a profilometer. SEM technique was used to study the mechanism of the surface formation in microscale. Results from this experimental study provides rich information on the cutting mechanisms during ceramics machining and the chemo-mechanical effects on the machining efficiency.
Error Minimization in Numerical Controlled Machining.
(1985) Anjanappa, M.; Kirk, J.A.; Anand, Davinder K.; ISR
Material removal rate in numerical controlled machining, especially in thin rib machining, is limited by the onset of tool path error and chatter. In this paper we propose that it is possible to increase the metal removal rate while maintaining the required dimensional accuracy and surface finish by modeling the cutting process as stochastic. With this improved modeling it will be possible to predict the characteristics of finished surface more accurately. A methodology to identify the system parameters and the design of an optimal controller to minimize stochastic tool path error in thin rib machining is presented.
Implementation of a Flexible Manufacturing Protocol.
(1986) Kirk, J.A.; Anand, Davinder K.; Anjanappa, M.; Uppal, R.; ISR
This paper is concerned with the development and implementation of a flexible manufacturing protocol for automated machining. Of specific interest is the machining of prismatic parts in a flexible manufacturing cell. The flexible manufacturing protocol involves providing design input via a computer aided design environment, an expert system for establishing manufacturability of the design, an intelligent process planning module for optimal component machining, design data base in an IGES format, automatic generation of machining codes, finally, the downloading of machine data to the computer numerical control machine, where the manufacture of the designed part occurs.
An integrated Approach to Calibrate an Untended Machining System
(1991) Parker, J.E.; Zhang, G.M.; Kirk, J.A.; Anand, Davinder K.; ISR
This paper presents a new methodology for the calibration of an untended machining system. The methodology requires the calibration conducted under both static and dynamic loading conditions. The transformation matrix method was used to establish the mapping function between the performance measure of interest (input) and the control signal (output). A prototype system, building on an CNC machining center equipped with a magnetic spindle, was developed to demonstrate a strategy for monitoring the tool wear progress through the cutting force prediction. The effect of phase distortion due to the presence of time lag on the output prediction was studied. A performance index to characterize the phase distortion error was suggested for further improvement of untended machining.
Magnetic Bearing Spindles for Enhancing Tool Path Accuracy.
(1985) Anand, Davinder K.; Kirk, J.A.; Anjanappa, M.; ISR
Thin rib machining of electronic components or airframe structures can beneflt from high speed machining for burr free cuttlag, improved surface quality and increased metal removal rate. It is suggested that the use of a magnetic bearing spindle can not only successfully provide the beneflts of high speed machining but, more importantly, minimize tool path errors. In this paper the various sources of tool path errors are discussed as functions of machine tool positioning errors and cutting force errors which are characterized as static, dynamic and stochastic. The operation of high speed magnetic bearing spindles is described and a control scheme whereby the spindle may be translated and tilted for minimizing tool path errors is discussed. This overall research activity is a cooperative effort between The University of Maryland, Cincinnati Milacron, and The National Bureau of Standards.
Research in the Flexible Manufacturing Laboratory.
(1986) Anand, Davinder K.; Kirk, J.A.; Anjanappa, M.; ISR
Systems research in the Flexible Manufacturing Laboratory (FML) consists of two thrust areas. The overall objective of the FMC research is concerned with interfacing various activities from design to component manufacturing. This includes such topics as the use of Artificial Intelligence (AI) in process planning, manufacturability evaluation via expert systems, and use of standardization within the cell. The research in magnetic bearings is concerned with control , stabilization of rotors , flywheels at high rotational speeds. Specific topics include the use of magnetic bearing spindles for machine tools, magnetic bearings for attitude control , energy storage in space, finally magnetic bearings for active vibration control in centrifuges , turbines for industrial use.
Study of the Formation of Macro-and-Micro-Cracks during Machining of Ceramics
(1993) Zhang, G.M.; Anand, Davinder K.; Ghosh, Subrata; Ko, Wing F.; ISR
This paper presents an experimental study on the formation of macro- and micro- cracks formed during the machining of ceramic materials. Aluminum oxide (Al2O3) was used as the testing material and polycrystalline diamond tipped carbide inserts were used for material removal. The cutting force was recorded during machining and surface finish was measured after machining. an environmental SEM was used to obtain high-magnification images of macro- and microcracks induced by machining. With the assistance of a computer-based vision system, qualification of fracture surfaces with respect to crack nucleation, growth, and cleavage was attempted. Results from this research provide an insight into the prevailing mechanisms of material removal during the machining of ceramics, and suggest the development of crack- controlled machining technologies.