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1987

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Articles 1 - 30 of 182

Full-Text Articles in Mechanical Engineering

Theoretical Thermodynamic Properties Of Low Temperature Fluids, Zul Azhar Zahid Jamal Dec 1987

Theoretical Thermodynamic Properties Of Low Temperature Fluids, Zul Azhar Zahid Jamal

Master's Theses

The thermodynamic functions for low temperature fluids are computed using parametric integral equations and perturbation theory. Parametric integral equation N is applied to a low temperature Lennard-Jones gas. It is found that there is no significant improvement over the better known parametric integral equation C. The two parameter integral equation T is applied to a low temperature square-well potential and is found to be unsatisfactory at reduced temperatures of T*= 1.4 and 1.6, but quite accurate at T* = 2.2. The equation T results for T* = 2.2 are used as the reference system in perturbation theory computations ...


Definition Of An Asymmetric Domain For Intercrystalline Misorientation In Cubic Materials In The Space Of Euler Angles, Brent L. Adams, Junwu Zhao Dec 1987

Definition Of An Asymmetric Domain For Intercrystalline Misorientation In Cubic Materials In The Space Of Euler Angles, Brent L. Adams, Junwu Zhao

Faculty Publications

The authors wish to acknowledge the support of the United States Department of Energy, Office of Basic Energy Sciences, under grant No. DE-FG02-85ER45203. Critical review by Professor Dorian Hatch of the Physics Department at Brigham Young University is gratefully acknowledged. A new asymmetric domain for intercrystalline misorientation is defined in the space of Euler angles for materials exhibiting cubic (Oh point-group) lattice symmetry. The invariant measure for this new domain is nearly constant; this is in significant contrast to the previous domain defined by MacKenzie [Biornetrika (1958), 45, 229-240]. Distribution functions in the misorientation can now be represented with greater ...


An Update To The Mitre/Wpi Space Shuttle Prgoram: Gascan G-408, Fred J. Looft, William W. Durgin Oct 1987

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

Office of the Provost and Vice President of Academic Affairs 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.


A Turbulence Model For The Heat Transfer Near Stagnation Point Of A Circular Cylinder, Mounir B. Ibrahim Sep 1987

A Turbulence Model For The Heat Transfer Near Stagnation Point Of A Circular Cylinder, Mounir B. Ibrahim

Mechanical Engineering Faculty Publications

A one-equation low-Reynolds number turbulence model has been applied successfully to the flow and heat transfer over a circular cylinder in turbulent cross flow. The turbulence length-scale was found to be equal 3.7y up to a distance 0.05δ and then constant equal to 0.185δ up to the edge of the boundary layer (wherey is the distance from the surface and δ is the boundary layer thickness).

The model predictions for heat transfer coefficient, skin friction factor, velocity and kinetic energy profiles were in good agreement with the data. The model was applied for Re ≤250 ...


The Effects Of A Mandatory Early Shutdown Of Maine Yankee, Maine State Planning Office Sep 1987

The Effects Of A Mandatory Early Shutdown Of Maine Yankee, Maine State Planning Office

Maine Collection

The Effects of a Mandatory Early Shutdown of Maine Yankee

Maine State Planning Office - Richard Silkman, Director (September 1987).

Contents: Introduction / Legal Issues / Economic Issues / Health and Environmental Issues / Conclusions / Appendices


Topology And Grid Adaption For High-Speed Flow Computations, Jamshid Samareh Abolhassani Jul 1987

Topology And Grid Adaption For High-Speed Flow Computations, Jamshid Samareh Abolhassani

Mechanical & Aerospace Engineering Theses & Dissertations

This study investigates the effects of grid topology and grid adaption on numerical solutions of the Navier-Stokes equations. In the first part of this study, a general procedure is presented for computation of high-speed flow over complex three-dimensional configurations. This includes the grid generation and solution algorithm for Navier-Stokes equations in a general three-dimensional curvilinear coordinate system. The flow field is simulated on the surface of a Butler wing in a uniform stream. Results are presented for Mach number 3.5 and a Reynolds number of 2,000,000. The O-type and H-type grids have been used for this study ...


Stress Analysis Of A Stepped Shaft With A Keyway, Irfan Hussain Sabir May 1987

Stress Analysis Of A Stepped Shaft With A Keyway, Irfan Hussain Sabir

Theses

A stress concentration case which is encountered in practice more than any other is the shoulder fillet. Shafts, axles, spindles, rotors etc., usually involve, in each case, a number of diameters connected by shoulders with fillet radii and very often it is necessary for a keyway to be near a shoulder. The objective in this study is to analyse the stresses in a shouldered shaft with a keyway subjected to an axial tensile load and to study the dependence of the keyway-end stresses on the distance between the shoulder fillet and the keyway end. This is done by performing a ...


Sub-Optimal Algorithms For Force Distribution In Multifingered Grippers, Vijay Kumar, Kenneth J. Waldron Mar 1987

Sub-Optimal Algorithms For Force Distribution In Multifingered Grippers, Vijay Kumar, Kenneth J. Waldron

Departmental Papers (MEAM)

The work described in this paper addresses the problem of determination of the appropriate distribution of forces between the fingers of a multifingered gripper grasping an object. The system is statically indeterminate and an optimal solution for this problem is desired for force control. A fast and efficient sub-optimal method for computing the grasping forces is presented. This method is based on the superposition of finger-interaction forces on equilibrating forces. An interaction force is defined as the component of the vector difference of the finger contact forces at any two fingers along the line joining the two contact points. They ...


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 Mar 1987

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 and Vice President of Academic Affairs 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 ...


Tone Generation By Flow Past Deep Wall Cavities, D. D. Erickson, William W. Durgin Jan 1987

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

Office of the Provost and Vice President of Academic Affairs 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 ...


Thermomechanical Design Criteria For Zr02-Y203 Coated Surfaces, J. Padovan, Benjamin T.F. Chung, Glen E. Mcdonald, Robert C. Hendricks Jan 1987

Thermomechanical Design Criteria For Zr02-Y203 Coated Surfaces, J. Padovan, Benjamin T.F. Chung, Glen E. Mcdonald, Robert C. Hendricks

Mechanical Engineering Faculty Research

Thermocycling of ceramic-coated turbomachine components produces high thermomechanical stresses that are mitigated by plasticity and creep but aggravated by oxidation, with residual stresses exacerbated by all three. These residual stresses, coupled with the thermocyclic loading, lead to high compressive stresses that cause the coating to spall. In the paper a ceramic-coated gas path seal is modeled with consideration given to creep, plasticity, and oxidation. The resulting stresses and possible failure modes are discussed.


Issues In The Design And Implementation Of Expert Systems, Clive L. Dym Jan 1987

Issues In The Design And Implementation Of Expert Systems, Clive L. Dym

All HMC Faculty Publications and Research

This article discusses the issues that arise in the design and implementation of expert systems. These issues include: task selection; the stages of development of expert system projects; knowledge acquisition; languages and tools; development and run-time environments; and organizational and institutional issues. The article closes with some speculation about the future development of expert systems.


A Feasibility Study Of The Development Of An Ibm Pc-Based Programmable Controller Ladder Logic Programming System /, Steven M. Howard Jan 1987

A Feasibility Study Of The Development Of An Ibm Pc-Based Programmable Controller Ladder Logic Programming System /, Steven M. Howard

Theses and Dissertations

No abstract provided.


Quantity Analysis, Forecast Model Application And Slotting Policies Design For The Itematic System Design /, Fu-Ann Liou Jan 1987

Quantity Analysis, Forecast Model Application And Slotting Policies Design For The Itematic System Design /, Fu-Ann Liou

Theses and Dissertations

No abstract provided.


The Control Of Search Techniques And Search Strategies Using Petri Nets In The National Bureau Of Standard's Real-Time Control System /, Barbara S. Timpte Jan 1987

The Control Of Search Techniques And Search Strategies Using Petri Nets In The National Bureau Of Standard's Real-Time Control System /, Barbara S. Timpte

Theses and Dissertations

No abstract provided.


Etching Radiation Treated Polyimide Films In O2/Nf3 And O2/Cf4 Plasmas /, Eric P. Dibble Jan 1987

Etching Radiation Treated Polyimide Films In O2/Nf3 And O2/Cf4 Plasmas /, Eric P. Dibble

Theses and Dissertations

No abstract provided.


Development Of Software For Localized 3d Shading /, Scott E. Bohman Jan 1987

Development Of Software For Localized 3d Shading /, Scott E. Bohman

Theses and Dissertations

No abstract provided.


A Heuristic Algorithm To Assign Orders Into Order Picking Lots In A Semi-Automated Warehouse /, Justin Khoe Jan 1987

A Heuristic Algorithm To Assign Orders Into Order Picking Lots In A Semi-Automated Warehouse /, Justin Khoe

Theses and Dissertations

No abstract provided.


Functional Specification Definition For Manufacturing Resource Planning Software /, Manish Shah Jan 1987

Functional Specification Definition For Manufacturing Resource Planning Software /, Manish Shah

Theses and Dissertations

No abstract provided.


A Study Of Modernization/Integration Of The Manufacturing Operation In A Small, Food Company /, Faith Dauberman Clark Jan 1987

A Study Of Modernization/Integration Of The Manufacturing Operation In A Small, Food Company /, Faith Dauberman Clark

Theses and Dissertations

No abstract provided.


A Relational Database In Support Of A Cim System /, Ronald Habakus Jan 1987

A Relational Database In Support Of A Cim System /, Ronald Habakus

Theses and Dissertations

No abstract provided.


Ultrasonic Characterization Of Residual Stress And Texture In Cast Steel Railroad Wheels, A. V. Clark, H. Fukuoka, D. V. Mitraković, J. C. Moulder Jan 1987

Ultrasonic Characterization Of Residual Stress And Texture In Cast Steel Railroad Wheels, A. V. Clark, H. Fukuoka, D. V. Mitraković, J. C. Moulder

Review of Progress in Quantitative Nondestructive Evaluation

An ultrasonic technique has been used to characterize the state of residual stress and texture in the rims of cast steel railroad wheels. Orthogonally polarized shear-horizontal (SH) waves are propagated through the thickness of the rim in pulse-echo mode. The (normalized) difference of arrival times of these waves (acoustic birefringence) depends upon both texture and stress. The birefringence, B, was measured with two transducers: an electromagnetic-acoustic transducer (EMAT) and a piezoelectric transducer made of PZT.

Two wheels were tested. The first wheel had a sawcut, which locally relieved the residual (hoop) stress. Measurement of the birefringence at the sawcut allowed ...


Ultrasonic Studies Of Stresses And Plastic Deformation In Steel During Tension And Compression, J. Frankel, W. Scholz Jan 1987

Ultrasonic Studies Of Stresses And Plastic Deformation In Steel During Tension And Compression, J. Frankel, W. Scholz

Review of Progress in Quantitative Nondestructive Evaluation

A steel bar subjected to four-point bending was instrumented so that various strains and sound velocities could be measured during elastic and plastic deformation on both the tension and compression side of the bar. During plastic deformation, the load was reduced several times before it was increased again. We present the acoustoelastic constants and the corresponding third-order elastic constants 1, m, and n in both tension and compression in the “as-treated” specimen and after various amounts of plastic deformation. The changes in various sound velocities with plastic deformation are also discussed.


Uniaxial Stress Effects On The Low-Field Magnetoacoustic Interactions In Low And Medium Carbon Steels, D. Utrata, M. Namkung Jan 1987

Uniaxial Stress Effects On The Low-Field Magnetoacoustic Interactions In Low And Medium Carbon Steels, D. Utrata, M. Namkung

Review of Progress in Quantitative Nondestructive Evaluation

In the past, we have shown that the low-field magnetoacoustic technique is capable of detecting uniaxial compression in steel components without necessiating a calibration standard [1,2]. This is because the initial slope of the AF(B)/F curve (fractional frequency change of phase-locked acoustic waves as a function of net magnetic induction) is negative only under compression and positive otherwise, when the specimens are magnetized along the static unaxial stress axis.


Evaluation Of Porosity In Graphite-Epoxy Composite By Frequency Dependence Of Ultrasonic Attenuation, David K. Hsu, Satish M. Nair Jan 1987

Evaluation Of Porosity In Graphite-Epoxy Composite By Frequency Dependence Of Ultrasonic Attenuation, David K. Hsu, Satish M. Nair

Review of Progress in Quantitative Nondestructive Evaluation

The ultrasonic attenuation of a solid containing a distribution of voids depends on the number of voids per unit volume and the ultrasonic scattering cross-section of the voids. This physical picture has been shown to provide an accurate description of the attenuation behavior of ultrasound in metals containing low level porosity. For example, methods developed from this model for evaluating the average size and the volume fraction of porosity in cast aluminum have yielded good results [1].


Compressive Stress Effects On The Ultrasonic Detection Of Cracks In Welds, Thomas A. Siewert, Raymond E. Schramm Jan 1987

Compressive Stress Effects On The Ultrasonic Detection Of Cracks In Welds, Thomas A. Siewert, Raymond E. Schramm

Review of Progress in Quantitative Nondestructive Evaluation

Crack closure due to external bending forces or residual stresses is an important concern in any nondestructive examination. It is particularly important in ultrasonic examination since this technique depends on the change in acoustic impedance at the crack interface to produce the reflected wave. If the two surfaces come into intimate contact somewhere along the crack due to closure effects, partial transmission can occur [1]. This partial transmission reduces the reflected signal and so underestimates the flaw depth when sizing is based on the reflected signal amplitude.


Determining Crack Tip Shielding By Means Of Acoustic Transmission And Diffraction Measurements, Otto Buck, David K. Rehbein, R. Bruce Thompson Jan 1987

Determining Crack Tip Shielding By Means Of Acoustic Transmission And Diffraction Measurements, Otto Buck, David K. Rehbein, R. Bruce Thompson

Review of Progress in Quantitative Nondestructive Evaluation

Asperity contact along the fracture surface of a crack is one of the mechanisms of crack closure. This contact shields the crack tip, in part, from the externally applied driving force on the crack. We have now succeeded in using experimental information, obtained under plane strain conditions from acoustic transmission and diffraction experiments in the closure region [1,2] to determine a stress intensity factor, KI(local), which shields the crack tip below a stress intensity factor KIclosure a t first contact during unloading occurs.


Ultrasonic Attenuation As A Trace Of Growth Of Fatigue Crack In Steels, Zhengliang Pan Jan 1987

Ultrasonic Attenuation As A Trace Of Growth Of Fatigue Crack In Steels, Zhengliang Pan

Review of Progress in Quantitative Nondestructive Evaluation

Two comprehensive overviews on ultrasonic quantitative nondestructive evaluation and materials characterization were recently given by Thompson [1] and Green [2] respectively. Ultrasonic attenuation measurements are used to study a great variety of material microstructures and associated mechanical properties. On the other hand, fracture mechanics provides a basis for some failure models for cracks, inclusions, voids, etc. A fracture mechanical analysis for ultrasonic measurements in cracked specimens should give some new informations, which will be useful for quantitative NDE.


Ultrasonic Characterization Of Diffusion Bonds, B. H. Hosten, L. A. Ahlberg, B. R. Tittmann, J. Spingarn Jan 1987

Ultrasonic Characterization Of Diffusion Bonds, B. H. Hosten, L. A. Ahlberg, B. R. Tittmann, J. Spingarn

Review of Progress in Quantitative Nondestructive Evaluation

The characterization of weak (low ultimate tensile stress) diffusion bonds is a generic problem which continues to challenge the QNDE community.1 Here we present preliminary results for an approach based on ultrasound reflection from, and transmission through, a planar diffusion bond. The samples consisted of two bonded stainless steel cylinders, each 12.7 mm in diameter and 63.5 mm in length. The bonds were made by means of thin Ag layers deposited on each of the matching ends of the cylinders. Here the ultrasonic transducers are placed at the ends of the cylinders. For this geometry, some of ...


In-Process Ultrasonic Evaluation Of Spot Weld Quality, S. I. Rokhlin, S. Meng, Laszlo Adler Jan 1987

In-Process Ultrasonic Evaluation Of Spot Weld Quality, S. I. Rokhlin, S. Meng, Laszlo Adler

Review of Progress in Quantitative Nondestructive Evaluation

While spot welding has wide use in the automotive and aerospace industries there is no acceptable nondestructive testing technique for evaluation of its quality. One of the major metallurgical defects of spot welds, the stick weld, cannot be evaluated at all. There is growing interest in the industry to develop simple production-oriented nondestructive techniques for evaluation of spot weld quality.