Engineering Commons^™

Limitations Of Current Design Procedures For Steel Members In Space Frames, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

The use of more advanced methods of analysis to design steel frames may lead to substantial material savings, in addition to simplicity in the design procedures. However, these benefits do not yet appear to be a powerful incentive for many structural engineers to abandon the familiar linear elastic analysis (LEA) based design procedures, even when dealing with steel structures that are not regular rectangular frames. This paper uses a heuristic example to demonstrate the serious limitations of the LEA based design procedures, whether alignment charts or system buckling analysis is used to determine the effective lengths of the compression members. …

A Simple, Robust, And On-Site Microwave Technique For Determining Water-To-Cement Ratio (W/C) Of Fresh Portland Cement-Based Materials, K. Mubarak, Karl Joseph Bois, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Inspection and evaluation of cement-based materials such as concrete is of great interest to the construction industry. In particular, real-time and on-site evaluation of water-to-cement ratio (w/c) is an important practical issue, since the compressive strength of a concrete structure is significantly influenced by its w/c. Currently, there is no single real-time, on-site, relatively in-expensive, easy-to-implement, and operator friendly technique for evaluating this parameter. Microwave nondestructive testing and evaluation techniques have shown great promise when used for inspection and evaluation of the properties of cement-based materials. In this paper, the optimal design of a monopole antenna probe used to evaluate …

Resilient Modulus Of Kentucky Soils, Tommy C. Hopkins, Tony L. Beckham, Charlie Sun, Bixian Ni

Kentucky Transportation Center Research Report

In recent years, the American Association of State Highway Transportation Officials (AASHTO) has recommended the use of resilient modulus for characterizing highway materials for pavement design. This recommendation evolved as of a result of a trend in pavement design of using mechanistic models, which are based on the theory of elasticity (layered elastic analysis) or linear and non-linear, finite elements (and finite difference methods), or a combination of both of those theoretical approaches. Although much progress has been made in recent years in developing mathematical, mechanistic pavement design models, results obtained from those models are only as good as the …

Design And Fabrication Of On-Chip Inductors, Robert K. Requa

Journal of the Microelectronic Engineering Conference

An inductor is a conductor arranged in an appropriate shape (such as a conducting wire wound as a coil) to supply a certain amount of self-inductance. This passive device stores magnetic energy. Simple spiral planar inductors of varying geometry were designed and fabricated on a silicon substrate insolated by silicon oxide. The process chosen for fabrication of the devices was the copper damascene process. Line widths and spaces varied from 5μm to 20μm. Thickness of the copper wire was approximately 1.5 μm. The inductors were isolated from the silicon substrate by 0.5 μm of Si0² and wires were insolated …

Design And Analysis Of A Cmos Based Mems Accelerometer, Matthew A. Zeleznik

Journal of the Microelectronic Engineering Conference

Traditionally, microelectromechanical systems (MEMS) have been fabricated using standard surface micromachining or bulk micromachining processes with prior or subsequent CMOS incorporation. Recently, a new hybrid technique known as CMOS enicromachining has been developed allowing for parallel fabrication of mechanical and electrical components. A single axis and dual axis accelerometer have been designed for submission for an ASIMPS alpha run using the CMOS micromachining process. Electrical and mechanical analysis and simulations for the single axis accelerometer have been performed. The sensitivity of the single axis accelerometer has been calculated to be 19.66mV/g neglecting the effects of parasitic capacitance. The released die …

Cubic Beam Elements In Practical Analysis And Design Of Steel Frames, Lip H. Teh

Faculty of Engineering - Papers (Archive)

This paper discusses various issues in the use of cubic beam elements for computer structural analysis/design of steel frames. It is pointed out that the concern expressed in recent literature regarding the number of cubic elements required to model a steel member is not justified, and that the inaccuracy of one cubic element in Euler buckling analysis of a simply supported column is largely irrelevant to the second-order elastic analysis/design or advanced analysis of steel frames. The sources of inaccuracy of the cubic element are elucidated. It is also explained that the plastic-zone analysis method is not so inefficient as …

Prototype Development For A Leak-Preventive Toilet Flush System- An Met Senior Design (Capstone) Project, Cheng Y. Lin

Engineering Technology Faculty Publications

A senior design (Capstone) project for three mechanical engineering technology students at Old Dominion University is described. A prototype design is presented to perform the functional test of a leak-preventive toilet system. There are two major leaks in the toilet water tank. In the first case, leaking occurs when the seal in the water tank becomes aged. The leak is very easy to detect visually, since the outside of the tank and the floor becomes wet. In the second case, leak occurs when the flapper valve can't complete shut off the water, due to corrosion or damage of the rubber …

The Effects Of Patch Properties On The Debonding Behavior Of Patched Beam-Plates, Anette M. Karlsson

Mechanical Engineering Faculty Publications

The debonding characteristics of patched structures are investigated in this study by means of an analytical model. In particular, the effects the lay-up sequence and edge tapering of a carbon-reinforced epoxy patch, as well as the beveling of an aluminum patch, have on the initiation, stability, and extent of the debonding are considered. The results presented show that both the degree of edge-tapering and the patch properties must be carefully selected in order to optimize the patched structure. It is also shown that when designing a patched system, it is important to model the correct boundary and load conditions to …

A New Autonomous Underwater Vehicle For Imaging Research, C. Roman, O. Pizarro, R. Eustice, H. Singh

Christopher N. Roman

Currently, unmanned underwater vehicles either tend to be cumbersome and complex to run, or operationally simple, but not quite suitable platforms for deep water imaging. This paper presents an alternative design in the form of a new low cost and easier to use autonomous underwater vehicle (AUV) for imaging research. The objective of the vehicle is to serve as a readily available and operationally simple tool that allows rapid testing of imaging algorithms in areas such as photomosaicking, 3D image reconstruction from a single camera, image based navigation, and multi-sensor fusion of bathymetry and optical data. These are all current …

Dc Power Bus Modeling In High-Speed Digital Designs Including Conductor And Dielectric Losses, Jun Fan, Hao Shi, James L. Knighten, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Power bus design is a critical aspect in high-speed digital circuit designs. A circuit extraction approach based on a mixed-potential integral equation formulation is presented herein to model arbitrary multilayer power bus structures including vertical discontinuities associated with surface mount (SMT) decoupling capacitor interconnects. Both conductor and dielectric losses are incorporated, and included into the first principles formulation. The agreement of modeling and measurements demonstrates its effectiveness and utilization in power bus designs.

Develop Design Data On Pressure Loss Of Large Pipe Fittings, Patrick Dent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pressure loss coefficients were determined for large radius ells, large concentric pipe reducers, and expansions, as well as large pipe tees. The fittings tested were 12, 16, 20, and 24 inch forged steel weld. Forty individual fittings from four different manufacturers were tested to determine loss coefficient values. Each test fitting was examined at a specified range of pipe velocities to determine mean and variation of loss coefficients. Tees were also examined for mean and variation of loss coefficients over a range of flow distributions.

Currently no data exists for pipe fittings of these larger diameters. This study will provide …

Design And Fabrication Of Ring Gate Surface Junction Tunneling Devices, Eliott R. Hughes

Journal of the Microelectronic Engineering Conference

Silicon based ring gate surface junction tunneling devices (SJT) were studied due to their promise of incorporating quantum functional devices with integrated circuits. SJT devices of various gate lengths ranging from 1 μm to 50 μm were designed using Mentor Graphics tools, and were fabricated using standard CMOS processes on S1MOX substrates. SIMOX wafers were used to help reduce bulk leakage and enhance the drain impurity profile. SIMOX mesa isolation also significantly reduced the process flow.

Toward A Heuristic Optimum Design Of Rolling Schedules For Tandem Cold Rolling Mills, Dadong Wang, A Kiet Tieu, Friso Deboer, B Ma, W. Y. Daniel Yuen

Faculty of Engineering and Information Sciences - Papers: Part A

Scheduling for tandem cold mills refers to the determination of inter-stand gauges, tensions and speeds of a specified product. Optimal schedules should result in maximized throughput and minimized operating cost. This paper presents a genetic algorithm based optimization procedure for the scheduling of tandem cold rolling mills. The optimization procedure initiates searching from a logical staring point - an empirical rolling schedule - and ends with an optimum cost. Cost functions are constructed to heuristically direct the genetic algorithm's searching, based on the consideration of power distribution, tension, strip flatness and rolling constraints. Numerical experiments have shown that the proposed …

Pavement Design Guide: A Short Course, Kentucky Transportation Center

Kentucky Transportation Center Research Report

The purpose of this short course is to provide information to the registered engineer (with no previous background in pavement design or pavement technology) on the structural design of pavements. Included in this course is a summary of background information on the materials used in pavement construction and on the history and evolution of pavement design. Included with this course is an updated Design Guide or catalog to be used for designing new pavements in Kentucky. The intent of the guide or catalog is to provide the road\\ a) designer with a simplified, straightforward methodology for developing structural designs of …

Finite Element Study Of Wellbore Stability, Karim Ibrahim Badawi

Archived Theses and Dissertations

No abstract provided.

Ventilation System Design Parameters For Greenhouses For Tobacco Production, R. S. Gates, George A. Duncan

Agricultural Engineering Extension Updates

Methods for germination and initial growth of tobacco have changed rapidly in recent years, moving from outside float beds into double-layer plastic greenhouses. Typically, these "tobacco greenhouses" consist of sidewall curtains, which run the entire length of both sides of the house. They may also have modest mechanical ventilation.

Ventilation of greenhouse structures is a mature field, with engineering practices for proper design given by numerous organizations including ASAE. In this article we briefly outline the important features of ventilation of concern to tobacco greenhouse operators.

Field-Programmable Smart-Pixel Arrays: Design, Vlsi Implementation, And Applications, Sherif S. Sherif, Stefan K. Griebel, Albert Au, Dennis Hui, Ted H. Szymanski, Harvard Scott Hinton

H. Scott Hinton

A smart-pixel array is a two-dimensional array of optoelectronic devices that combine optical inputs and outputs with electronic processing circuitry. A field-programmable smart-pixel array (FP-SPA) is a smart-pixel array capable of having its electronic functionality dynamically programmed in the field. Such devices could be used in a diverse range of applications, including optical switching, optical digital signal processing, and optical image processing. We describe the design, VLSI implementation, and applications of a first-generation FP-SPA implemented with the 0.8-μm complementary metal-oxide semiconductor–self-electro-optic effect device technology made available through the Lucent Technologies–Advanced Research Projects Agency Cooperative (Lucent/ARPA/COOP) program. We report spice simulations …

Sediment Control At Water Intakes Along Sand Bed Rivers, Fred L. Ogden

Fred L. Ogden

Results from five physical hydraulic model studies of riverside water intakes situated along the Missouri River reach between Sioux City, Iowa, and St. Louis, Missouri, are presented. Movable-bed, undistorted Froude-scale models are used to determine the effectiveness of structural modifications in the vicinity of the intake to limit the influx of bed-load sediments. Solutions developed in each case include a series of submerged flow-turning vanes located on the riverward side of the intake. A sediment-barrier wall between the vanes and intake ...

Analytical And Experimental Study Of Investment Casting With Laser Stereolithography Models, Wen-Long Yao

Dissertations

This dissertation presents an analytical and experimental investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography (SLA) patterns. Included in the consideration are the cracking temperature of the ceramic shell, the web link buckling temperature, and the glass transition temperature of the epoxy resin. The hypothesis is that shell cracking will occur when the cracking temperature is lower than the glass transition temperature and the web buckling temperature.

An analytical and experimental study has been conducted, with the cross-sectional area, the span length of the web structure, and the shell thickness being …

Dual Adaptive Recumbent Trike, Jason V. Eastman

Undergraduate Honors Capstone Projects

The DART team's objective was to develop a tandem recumbent tricycle that would be economical, easy to build, and adaptable. This would involve designing, building and testing the tricycle.

Parameter Optimization For Curl Distortion In Building Parts Using 3-D Laser Stereolithography, Laurel A. Hanesian

Theses

The curl distortions in rapid prototyping using 3-D laser stereo lithography occur as the top layers shrink after being drawn and attaching to the bottom layers. The amount of curl is dependent upon the how much shrinkage the layer has finished prior to adhesion. It is also dependent on how deep the cure of the top layer amounts to as it adheres into the bottom layer. This thesis investigated the effect of build parameters on the distortions associated with the diagnostic 'Letter-H' shaped test part. The same parameters were also considered in a time optimization study, using calculated, predicted results …

A Study To Analyze And Improve Mechanical And Electro-Mechanical Designs Using Design For Quality Manufacturability (Dfqm) Technique, Bhavani P. Veerapaneni

Theses

The competitive nature of modern manufacturing demands that an innovative approach be used to build advanced and robust designs. Shortening the product development time, which is the period from initial design to full production, is a priority to most manufacturers today. Design for Quality Manufacturability (DFQM) is a methodology to address manufacturing / assembly quality issues during product design. As a consequence DFQM helps shorten the product development time.

The DFQM methodology addresses the issue of quality manufacturability (QM) - the likely hood that defects will occur during the manufacture of a product in a standard plant. The DFQM architecture …

Design And Design Centers In Engineering Education, Clive L. Dym

All HMC Faculty Publications and Research

This paper is intended to be the opening salvo of the workshop, Computing Futures in Engineering Design (Dym, 1997). Thus, I want to take this privileged moment to ask you to think with me about the role of design in engineering. In particular, I want to reflect upon how design is articulated and how design is taught; about the role of design in engineering education and in the practice of engineering; and about the role that could be played locally and, perhaps, nationally by a center devoted to design education. Because I teach here at Harvey Mudd College (HMC), …

Design Of Tapered Augers For Uniform Unloading Particulate Material From Rectangular Cross-Section Containers, M. S. Burr, Michael F. Kocher, David D. Jones

Biological Systems Engineering: Papers and Publications

The design equation for an auger to provide uniform unloading of particulate material from a container with a rectangular cross-section (Jones and Kocher, 1995) was revised to account for the minimum flighting height that could effectively unload particles with a known average smallest diameter. A minimum flighting height that was about 64% of the average smallest diameter of the particles was experimentally determined to obtain mean slopes of the top surface of the material not significantly different from zero for screened soybeans. A linear taper that best fit the square root curve for the inside diameter of the auger was …

Embankment Construction Using Shale, Tommy C. Hopkins, Tony L. Beckham

Kentucky Transportation Center Research Report

Shales have been used extensively in the construction of highway embankments, and other earthen structures, because of the vast amounts of these materials located in many areas of the country and the lack of economical and alternate available materials. Because shales exhibit a wide range of engineering properties and behaviors, many problems have occurred. Numerous shale embankment failures have occurred generally some 1 to 10 years after construction. Settlements of 1 to 3 feet (0.3 - 0.9 m) have been observed in many old embankments and required numerous asphaltic overlays. Shale embankments that settle continuously have been observed to fail …

Designing A Higher Layer Protocol For Small Distributed Microcontroller Systems Using The Control Area Network Protocol, Long G. Nguyen

Theses: Doctorates and Masters

This thesis is concerned with designing a Higher Layer Protocol (HLP) for small distributed microcontroller systems using a well-established network protocol: the Controller Area Network (CAN) protocol which, currently, is widely used in the automation industries. Steps were taken to investigate three popular HLPs based on the CAN protocol: namely. Smart Distributed System (SDS), DeviceNet. and CAN Kingdom. Following the comparison of the three HLPs, the CAN Kingdom protocol was chosen for the task of designing the HLP in this project in order to satisfy the restrictions associated with small systems. Thus, the HLP (named the Small CAN Kingdom protocol) …

Subsurface Drainage Of Highway Pavements, David Q. Hunsucker, Bobby W. Meade

Kentucky Transportation Center Research Report

Properly designed and constructed drainage layers can be used for effective control of surface water infiltration. Former pavement design methods often have resulted in base courses that have not drained well, thereby resulting in some premature failures of the pavement structure. The Kentucky Department of Highways is currently reviewing proposed guidelines for design of highway pavements. The guidelines propose the use of open graded, free draining, aggregate bases for controlling infiltrated surface water. However, interim design guidelines do not specifically address the design of aggregate drainage blankets. The purpose of this study was to develop recommendations relating to the specification, …

Design Improvement Using Reverse Analysis In Design For Quality Manufacturability, Vikram V. Datla

Theses

The competitive needs of modern manufacturing demands that innovative approaches be used to gain an edge over the competitors. least Product design is one of the key dimensions wazzu in which companies can excel. Shortening the product design cycle so as to rapidly launch defect free products, is the goal of most companies. Design for Quality Manufacturability (DFQM) is a technique used to evaluate the quality manufacturability of a product at the design stage, so as to eliminate quality problems during production.

DFQM provides a means for relating the activities of quality improvement, product design and manufacturability analysis. The basis …

Design And Characterization Of A Microchannel Optical Interconnect For Optical Backplanes, Yongsheng Liu, Brian Robertson, David V. Plant, Harvard Scott Hinton, William M. Robertson

H. Scott Hinton

The design, modeling, and experimental characterization of a microchannel-based free-space optical interconnect is described. The microchannel interconnect was used to implement a representative portion of an optical backplane that was based on field-effect transistor, self-electro-optic device smart-pixel transceivers. Telecentric relays were used to form the optical interconnect, and two modes based on two different optical window clusterings were implemented. The optical system design, including the optical geometry for different degrees of clustering of windows supported by a lenslet relay and the image mapping associated with a free-space optical system, is described. A comparison of the optical beam properties at the …

Design And Characterization Of An Optical Proximity Correction (Opc) Mask, Sumir Varma

Journal of the Microelectronic Engineering Conference

A normal binary chrome mask is designed with optical proximity correction features to test their effect on the lithographic image formed. A significant image improvement is seen due to the addition of the OPC features.