Engineering Commons^™

Numerical Representation Of Bodner Viscoplastic Constitutive Model, Faysal A. Kolkailah, Andrew J. Mcphate

Aerospace Engineering

Nonlinear analyses of structural components are normally carried out by finite element codes making Use of constitutive theories in which the material response is separated into the two important groups of phenomena known as rate‐dependent “creep” and rate‐independent “plasticity.” A number of viscoplastic constitutive theories in which creep and plasticity effects are combined into a unified plastic strain model have recently been proposed and are still undergoing active development. In this paper, the constitutive equations of the Bodner‐Partom model are used to present the time dependent, inelastic properties of Inconel 718 at 650 °C. This representation covers a wide range …

Integrating Scheduling And Control Functions In Computer Integrated Manufacturing Using Artificial Intelligence, Luis Carlos Rabelo, Sema E. Alptekin

Industrial and Manufacturing Engineering

Proper integration of scheduling and control in Flexible Manufacturing Systems will make available the required level of decision-making capacity to provide a flexibly-automated, efficient, and quality manufacturing process. To achieve this level of integration, the developments in computer technology and sophisticated techniques of artificial intelligence (AI) should be applied to such FMS functions as scheduling. In this paper, we present an Intelligent Scheduling System for FMS under development that makes use of the integration of two AI technologies. These two AI technologies — Neural Networks and Expert Systems — provide the intelligence that the scheduling function requires in order to …

Using Living Materials To Intervene In The Natural Succession Process To Accelerate The Re-Development Of A Self-Sustaining Ecosystem That Has Been Damaged By Human Intervention, Eric Jorgensen

Materials Engineering

No abstract provided.

Group Set-Up For Printed Circuit Board Assembly, Tali F. Carmon, Oded Z. Maimon, Ezey M. Dar-El

Industrial and Manufacturing Engineering

The current practice in the assembly of electronic components on printed circuit boards (PCBs) is serial production. a process characterized by very long set-up times. However, with the advent of efficient on-line process information .. new production control methods are now possible. This paper proposes a different production method, called the group set-up (GSU) method, which can significantly reduce set-up times. The traditional and the GSU production methods are compared, and it is shown that the GSU always performs better than the traditional method in terms of total production flow (throughput) and labour time However, the traditional method performs better …

The Role Of The Peripheral Vascular Bed In Arterial Pulse Wave Propagation, L. S. Baker, F. A. Anderson, Jr., H. B. Wheeler, William W. Durgin

Office of the Provost Scholarship

An analytical model was developed to simulate human arterial pulse wave propagation in major arteries. It was verified with an experimental model. The models investigated the effects of the peripheral vascular bed on pressure pulse morphology. The models revealed that the capillary bed in normal humans acts as a high resistance, low reflectance, boundary condition.

A Systematic Transition To Flexible Manufacturing, Sema E. Alptekin, Daniel L. Webber

Industrial and Manufacturing Engineering

The transition from basic automation to flexible manufacturing is an expensive and tedious procedure. It requires meticulous planning and almost clairvoyant forecasting to insure that the initial flexibility obtained is sufficient to allow growth and expansion in the future. This paper will suggest a systematic and methodological approach to achieve optimal flexibility and describe the present results of its application to an ongoing system transformation. Conclusions based on existing levels of completion are presented along with identification of critical and non critical flexibility requirements. The considerations and steps taken are summarized in a procedural format which may then be applied …

A 100-Khz - 22 Ghz Instrumentation Photoreceiver, Dennis J. Derickson, C. M. Miller, R. L. Van Tuyl

Electrical Engineering

A photoreceiver consisting of a high-speed p-i-n photodetector and a 100-kHz to 22-GHz distributed amplifier is described. Photoreceiver calibration is accomplished by optical heterodyne techniques. The photoreceiver is used with a microwave spectrum analyzer to produce a fully amplitude-calibrated 22-GHz-bandwidth lightwave signal analyzer system for displaying intensity-modulated light with -65-dB (optical) sensitivity at 1300-nm and 1550-nm wavelengths.

Proposed Scheduling Methods For Printed Circuit Board Assembly, Tali Freed, Ezey M. Dar-El, Oded Z. Maimon

Industrial and Manufacturing Engineering

The current practice in the assembly of electronic components on printed circuit boards (PCB's) is serial production, a process characterized by very long set-up times.

However. with the advent of efficient on-line process information, new production control methods are now possible. This paper proposes two new production methods - the Grouped Set-up (GSU) method and the Sequence-Dependent Scheduling (SDS) method, which can significantly reduce set-up times.

It is shown that the GSU always performs better than the SDS method in terms of total production flow (throughput). while the SDS performs better than the GSU method in terms of work-in-process (WIP) …

An Update To The Mitre/Wpi Space Shuttle Prgoram: Gascan G-408, Fred J. Looft, William W. Durgin

Office of the Provost Scholarship

The objective of the MITRE/WPI Space Shuttle Program was to develop a set of scientific meaningful experiments that could be flown in a Get Away Special Canister. currently, the first GASCAN is finished (G-408) and ready to be launched. The program has been so successful that the design and development of a second set of experiments has been started (G-533). This paper will describe and summarize both of these programs.

Low Cost Software, Harold M. Cota

Civil and Environmental Engineering

This is the fifth in our series on low cost software available to JAPCA readers. These programs have been developed by APCA members and are provided as a professional courtesy, as is, without warrantee. The authors would appreciate any feedback you have. In addition, we hope you will be willing to share programs you have developed for your own PC. To share your program all you need to do is prepare a brief description, similar to those in this column and send it with your program and any examples or documentations you are willing to furnish to: Dr. Hal Cota, …

Surabaya Indonesia: Options In Solid Waste Management, Samuel A. Vigil

Civil and Environmental Engineering

The Government of Indonesia requested assistance from the United States Trade and Development Program (TDP) regarding improvements to the solid waste management system of the City of Surabaya. TDP retained the author to prepare a Preliminary Feasibility Study which will enable TDP to make an informed decision on the desirability of funding further engineering work leading to solid waste projects.

The Use Of Ultrasound Imaging In The In-Vivo Determination Of Normal Human Arterial Compliance, Lauren I. Stratouly, Paul A. Cardullo, Frederick A. Anderson Jr., William W. Durgin, H. Brownell Wheeler

Office of the Provost Scholarship

Elastic properties of major arteries were measured in vivo in ten normal volunteers, age 26 to 44 years (mean = 32 years). A B-mode ultrasound imager was used to noninvasively measure mean diameter and pulsatile diameter change at five locations along the main arteries in the abdomen and the lower extremities. Together with pulsatile pressure (measured by the auscultatory method), strain (ε), compliance (C) and the pressure-strain elastic modulus (Ep l/C) were calculated. Ep increased significantly along the arterial tree; mean values (x10⁵ N/m^-2 ) were: 0.99 aorta, 1.21 common iliac artery (CIA), 1.43 common femoral artery (CFA), …

Microcomputer Model For Solid Waste Planning, Samuel A. Vigil, Jane A. Zevely, Roy Yeaman

Civil and Environmental Engineering

No abstract provided.

Tone Generation By Flow Past Deep Wall Cavities, D. D. Erickson, William W. Durgin

Office of the Provost Scholarship

Flow past deep wall cavities exhibits strong interaction with the standing wave system in the cavity. The shear layer separating the exterior flow from the cavity flow supports instabilities which excite the normal cavity modes. In turn, the cavity wave system reinforces the instabilities. Experimental studies have shown that two distinct instability modes are encountered as the external velocity is increased. The pressure coefficient versus Strouha1 number behavior reveals two maxima which correspond to different instability modes of the shear layer. Flow visualization studies have shown that these modes correspond to distinct shear 1ayer vortex structures. At high velocities, single …

Guarding Against Machine Hazards, R. A. Cavaletto

BioResource and Agricultural Engineering

Successful guarding strategies requires knowledge of machine functions, the physical and psychological characteristics of man, and the their interactions. Machine hazards are identified along with recognized guarding methods. Material is included that could be used to teach this subject (case study, prob!em set, glossary}.

A Transient Electromagnetic Flowmeter, Paul J. Lefebvre, William W. Durgin

Office of the Provost Scholarship

An electromagnetic flowmeter was developed to measure transient flows with a frequency response of 60 Hz. The approach taken was to develop suitable electronics to replace the electronics of a commercially available electromagnetic flowmeter normally used for steady-state operation. Use of the commercially available flowmeter body, which includes the magnetic coils, core, and signal electrodes, provided a relatively economical means of fabricating the transient flowmeter. A transient flow calibration facility consisting of a free-falling water column was also designed and built. Results of the calibrations are presented and show that the flowmeter can accurately measure transient flows up to the …

Shear Layer Coupling With Side-Branch Resonators, D. D. Erickson, William W. Durgin, C. F. Maguire Iii, M. J. Moeller

Office of the Provost Scholarship

High velocity flow past the junction of a side branch with a pipe can result in the excitation of depth-mode standing waves in the branch. The shear layer separating the main stream flow and the cavity provides coupling between the driving and the driven flow. Photographic evidence indicates that large scale vortex structures develop at the shear layer. The vortex formation process involves strongly non-linear instability of the shear layer and may be characterized as a non-linear fluid mechanical oscillator. The standing wave system formed in the cavity is essentially an acoustic wave system of nearly linear character. The principle …

Source Testing Software, Harold M. Cota

Civil and Environmental Engineering

Ifyou have been looking for a way to speed the calculation or reporting of source test data, this month's column will be of interest to you. Included in this review are one commercial program, several noncommercial programs, and a summary of programs that are available for programmable calculators. The author would appreciate knowing of similar programs that you may have developed or used.

Interpretation Of Venous Occlusion Plethysmography Using A Nonlinear Model, F. A. Anderson, Jr., William W. Durgin, H. Brownell Wheeler

Office of the Provost Scholarship

Venous occlusion plethysmography (VOP) is a noninvasive technique widely employed for the detection of deep-vein thrombosis. Previous reports that VOP outflow curves are closely fit by a first-order exponential suggest that venous compliance and resistance are nearly constant. Typically, however, the venous compliance function has a sigmoid shape; in addition, the resistance in a collapsing tube must increase. This paradox was resolved by the surprising finding that for realistic nonlinear compliance and resistance these nonlinearities cancel, producing a quasilinear venous outflow that approximates a simple exponential.

Microcomputer Solid Waste Financial Model, Samuel A. Vigil, Jane A. Zevely

Civil and Environmental Engineering

Applications of a microcomputer based solid waste financial model will be described. The model is written as an overlay to the Lotus 1-2-3 spreadsheet program. It makes use of the Lotus 1-2-3 macro programming capabilities and is menu driven, requiring minimal computer skills for use. The model allows engineers to estimate costs for recycling centers, waste-to-energy plants, and landfills. Outputs include summary tables of operational and capital costs, as well as a 20 year proforma income statement. The model was developed for the California Waste Management Board, an agency of the State of California, and will be distributed by them.

State-Feedback Control Of Non-Linear Systems, Stanislaw H. Żak, Carl A. Maccarley

Electrical Engineering

A design method for state-feedback controllers for single-input non-linear systems is proposed. The method makes use of the transformations of the non-linear system into ‘controllable-like’ canonical forms. The resulting non-linear state feedback is designed in such a way that the eigenvalues of the linearized closed-loop model are invariant with respect to any constant operating point. The method constitutes an alternative approach to the design methodology recently proposed by Baumann and Rugh. Also a review of different transformation methods for non-linear systems is presented. An example and simulation results of different control strategies are provided to illustrate the design technique.

Evaluation Of Two Models For Light Transmission In Biological Materials, R. A. Cavaletto, S. Upadhyaya, M. O'Brien, T. Cahill

BioResource and Agricultural Engineering

Two light transmission models for biological materials are developed and evaluated. The energy balance model showed promise. It's developed as a 3 coefficient model permitting varied sample absorption and scattering properties. The second model performed unsatisfactorily.

Ultrasonic Fluid Measurement, William Durgin

Office of the Provost Scholarship

Objective: Determination of liquid quantity and configuration under static and dynamic conditions.
Important for: consumption resupply manufacturing

Utilization Of Electronic Spreadsheets For Laboratory Data Analysis, C. F. Maguire Iii, William W. Durgin

Office of the Provost Scholarship

The utilization of business spreadsheets for laboratory data manipulation is discussed. The spreadsheet, LOTUS 1-2-3, is presently being utilized to store and analyze data obtained from a deep cavity resonator type apparatus. Methodology for the analysis, from non dimensionalization of parameters, to relevant plotting of data pairs, is presented. All discussions are based upon current theory, and laboratory observations of flow induced resonance in deep cavities.

New Specimen Design For Studying The Growth Of Small Fatigue Cracks With Surface Acoustic Waves, Blair London

Materials Engineering

The study of small surface fatigue cracks in AISI 4140 quenched and tempered steel by a nondestructive surface acoustic wave technique is summarized. A novel cantilevered bending, plate-type fatigue specimen is described that is compatible with the acoustic method. Small cracks are initiated from a 25-μm deep surface pit produced by an electrospark machine. The importance of studying these

Method And Apparatus For Generating Electrical Energy From A Heated Gas Containing Carbon Particles, Samuel A. Vigil, Rick B. Spielman

Civil and Environmental Engineering

Carbon particles entrained in the gas flow into a magnetohydrodynamic generator are electrostatically charged from a source of high voltage and then function as charge carriers in the MHD process. Lower flow temperatures may be used and seeding with alkali metal salts is unnecessary as the MHD process becomes independent of thermal ionization of constituents of the gas flow.

Noninvasive Detection Of Arterial Occlusive Disease: A Theoretical And Model Study, Lauren I. Stratouly, William W. Durgin, Frederick A. Anderson Jr., H. Brownell Wheeler

Office of the Provost Scholarship

To develop a noninvasive method of detecting arterial occlusive disease, pulse waveforms were recorded at two locations on the lower extremities of young normal volunteers and patients with arteriographically confirmed arterial occlusive disease. Pulses were monitored using impedance plethysmography at the knee· and the iliac regions. The frequency spectra of the abnormal iliac waveforms contained 4-5 harmonics as compared to the 2-3 harmonics present in normals'. It was hypothesized that the occurrence of high frequencies resulted from pulse wave interactions with diseased portions of the vessel. This paper will present the results of a theoretical and experimental model developed to …

Solid Waste Resource Recovery Alternatives, U.S. Facility, Subic Bay, Philippines, Samuel A. Vigil, R. M. Roberts, Donald E. Brunner

Civil and Environmental Engineering

The U.S. Navy Public Works Center, Subic Bay, Republic of the Philippines (PWC Subic Bay) is responsible for the collection and disposal of almost 300,000 yd³ of solid waste annually. A portion of this solid waste is manually sorted and recycled, resulting in gross revenues of over $200,000 in FY82. The present manual sorting and recycling system is considered by PWC Subic Bay to be inadequate in terms of sanitation, safety, and recyclable materials recovery. Therefore , PWC Subic Bay requested that the Naval Civil Engineering Laboratory (NCEL) study the system and recommend improvements.

Applications Of Optical Emission Spectroscopy To Semiconductor Processing, Richard N. Savage, John G. Shabushnig, Paul R. Demko

Materials Engineering

Optical emission spectroscopy (OES) has proven to be a valuable tool in the developmrent and production of state-of-the-art semiconductor devices. Application to the plasma etching of a variety of materials necessary for integrated circuit fabrication is discussed, with particular emphasis placed on etch endpoint analysis. The utility of OES techniques in monitoring photolithographic processes is also presented.

Evaluation Of Micro Irrigation Systems, Charles M. Burt, Robert E. Walker, Stuart W. Styles

BioResource and Agricultural Engineering

No abstract provided.