Mechanical Engineering Commons^™

Preliminary Design Of An Electrodynamic Balance For Single Particle Analysis, C. Bobcowski, J. Costa, S. Shaw, R. Zucal, J. Schmalzel, R. Ordonez, John Chen

Mechanical Engineering

An electrodynamic chamber (EDC) is a device that controls the electrodynamic field surrounding a single particle. By suspending the particle at a fixed point in space, various measurements can be made to determine thermodynamic properties of the particle. This paper describes the preliminary engineering development of an EDC for combustion research at Rowan University.

A Special Theory Of Biphasic Mixtures And Experimental Results For Human Annulus Fibrosus Tested In Confined Compression, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

A finite deformation mixture theory is used to quantify the mechanical properties of the annulus fibrosus using experimental data obtained from a confined compression protocol. Certain constitutive assumptions are introduced to derive a special mixture of an elastic solid and an inviscid fluid, and the constraint of intrinsic incompressibility is introduced in a manner that is consistent with results obtained for the special theory. Thirty-two annulus fibrosus specimens oriented in axial (n = 16) and radial (n = 16) directions were obtained from the middle-lateral portion of intact intervertebral discs from human lumbar spines and tested in a stress-relaxation protocol. …

Technology In Engineering Education: What Do The Faculty Know (And Want) Anyway?, John C. Chen, Michael Ellis, Jason Lockhart, Sameer Hamoush, Catherine E. Brawner

Mechanical Engineering

We have conducted a survey of engineering faculty at the eight SUCCEED coalition universities to identify the training needs and present levels of experience with various technologies. The results of that survey are presented in this paper.

The most surprising finding from the survey is that, despite the wide differences in the Coalition’s colleges of engineering (in size, student demographics, and research-teaching emphasis, for example), the survey results are similar for all campuses. This is important in that it implies that the survey results may be widely applicable to other universities, even given the disparate state of technology integration and …

Internally Constrained Mixtures Of Elastic Continua, Stephen M. Klisch

Mechanical Engineering

A treatment of internally constrained mixtures of elastic continua at a common temperature is developed. Internal constraints involving the deformation gradient tensors and the common mixture temperature are represented by a constraint manifold, and an internally constrained mixture of elastic continua is associated with each unique equivalence class of unconstrained mixtures. The example of intrinsic incompressibility of each constituent first proposed by Mills is discussed.

Collaborative Undergraduate Research, Hamid Davoodi, Frederick Just, Ali Saffar, Mohammad Noori, William W. Durgin

Office of the Provost Scholarship

A joint undergraduate research project between University of Puerto Rico at Mayagüez (UPRM) and Worcester Polytechnic Institute (WPI) started four years ago. Each year a group of students, varying between six and ten, from WPI will come to Puerto Rico to work with a group of students, varying from six to ten, from UPRM on a well defined research project. Although the topics of the projects have been different but all follow the same goal, Vibration Control of Structures by Utilizing Shape Memory Alloys. Each year the project starts on January and ends on May. Both groups of the students …

Simtrainer: A Management Training Tool, Wade Stark, Sema E. Alptekin

Industrial and Manufacturing Engineering

Abstract published of poster paper presented at conference.

Scheduling Semiconductor Device Test Operations On Multihead Testers, Tali Freed, Robert C. Leachman

Industrial and Manufacturing Engineering

Past attempts to devise scheduling methods for the device test operations of semiconductor manufacturing firms fail to address a significant characteristic of multiple-head test systems—the dependency of processing rates on the lots processed simultaneously on the testers. Since the problem has never been modeled accurately in the scheduling literature, feasibility and performance of previously proposed scheduling methodologies for multihead testers may not be accurately assessed. In this paper, we describe the multihead tester scheduling problem, present an enumeration solution procedure, and illustrate the problems of previously suggested tester scheduling algorithms.

An Evaluation Of Ploughing Models For Orthogonal Machining, Daniel J. Waldorf, Richard E. Devor, Shiv G. Kapoor

Industrial and Manufacturing Engineering

An analytical comparison is made between two basic models of the flow of workpiece material around the edge of an orthogonal cutting tool during steady-state metal removal. Each has been the basis for assumptions in previous studies which attempt to model the machining process, but no direct comparison had been made to determine which, if either, is an appropriate model. One model assumes that a separation point exists on the rounded cutting edge while the other includes a stable build-up adhered to the edge and assumes a separation point at the outer extreme of the build-up. Theories of elastic-plastic deformation …

Gauge Repeatability & Reproducibility Study For A 3-D Solder Paste Inspection System, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Due to the increased use of Ball Grid Arrays (BGAs) and fine pitch and ultra fine pitch Quad Flat Packages (QFPs), there is a dramatic increase in demand for solder paste inspection after the stencil printing process. The important response variables of the printing process are deposited solder paste volume, area, height and position. To identify and remove defects at the earliest possible process step, a 3-D solder paste inspection system should be used to monitor solder paste deposited on all pads on every board before component placement. An example is a fully automatic laser-based 3-D triangulation solder paste inspection …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high volume surface mount assembly. Control of the amount of solder paste deposited is critical for fine pitch and ultra-fine pitch SMT assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% of SMT defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the deposited solder paste volume, area, and height. An experiment was conducted to investigate the effects of relevant process parameters on the amount of …

Application Of A Fiber-Reinforced Continuum Theory To Multiple Deformations Of The Annulus Fibrosus, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

Accurate tissue stress predictions for the annulus fibrosus are essential for understanding the factors that cause or contribute to disc degeneration and mechanical failure. Current computational models used to predict in vivo disc stresses utilize material laws for annular tissue that are not rigorously validated against experimental data. Consequently, predictions of disc stress resulting from physical activities may be inaccurate and therefore unreliable as a basis for defining mechanical–biologic injury criteria. To address this need we present a model for the annulus as an isotropic ground substance reinforced with two families of collagen fibers, and an approach for determining the …

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960's. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

Industrial Engineering Made Simple, Deena Daggett, Sema E. Alptekin

Industrial and Manufacturing Engineering

Many high school students these days do not quickly recognize or identify Industrial Engineering (IE) procedures, practices, and products. Recruitment of qualified students into IE programs requires continuous planning, publicizing, and networking. Traditional recruitment efforts have included high school visits, brochures & flyers, and university-sponsored workshops. However, these techniques have only achieved mediocre success. Currently, a need exists for new promotional materials that utilize visual tools and provide a “hands-on” approach. We have developed several exercises that successfully introduce IE. Two such exercises are explained in this paper. The first exercise demonstrates the differences between Assembly line and Cellular Manufacturing …

Worn Tool Forces Based On Ploughing Stresses, Daniel Waldorf, Shiv G. Kapoor, Richard E. Devor

Industrial and Manufacturing Engineering

Recent work in modeling of the ploughing mechanism in basic metal machining may provide a means of estimating the additional forces to be expected when cutting with a worn tool. The results predict the rubbing stresses due to the finite radius of an unworn tool edge. Since an unworn tool can be thought of as a worn tool with a wear land width VB = 0, these stresses can make up part of a strategy for predicting the additional forces incurred by a worn tool. This paper develops a wear model by proposing a technique for utilizing the stresses predicted …

A Compensated Acoustic Actuator For Systems With Strong Dynamic Pressure Coupling, Charles Birdsong, Clark J. Radcliffe

Mechanical Engineering

This study improves the performance of a previously developed acoustic actuator in the presence of an acoustic duct system with strong pressure coupling. The speaker dynamics and the acoustic duct dynamics are first modeled separately. The two systems are then coupled, and the resulting system is modeled. A velocity sensor is developed and used in feedback compensation. The resulting speaker system has minimal magnitude and phase variation over a 20–200 Hz bandwidth. These conclusions are verified through experimental results.

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960’s. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

A Slip-Line Field For Ploughing During Orthogonal Cutting, Daniel J. Waldorf, Richard E. Devor, Shiv. G. Kapoor

Industrial and Manufacturing Engineering

Under normal machining conditions, the cutting forces are primarily due to the bulk shearing of the workpiece material in a narrow zone called the shear zone. However, under finishing conditions, when the uncut chip thickness is of the order of the cutting edge radius, a ploughing component of the forces becomes significant as compared to the shear forces. Predicting forces under these conditions requires an estimate of ploughing. A slip-line field is developed to model the ploughing components of the cutting force. The field is based on other slip-line fields developed for a rigid wedge sliding on a half-space and …

Fuzzy Logic Control Of A Model Airplane, Jon C. Ervin, Sema E. Alptekin

Industrial and Manufacturing Engineering

Common uses of fuzzy logic control today are found in relatively simple applications in products. These applications only scratch the surface of the potential of fuzzy logic control in complex mechatronic systems. In order to demonstrate the utility of fuzzy logic in complex device control, a fuzzy logic fly-by-wire system has been developed for a model airplane. The model airplane is a complex system of several critical inputs that require rapid processing and action in order to maintain flight stability. In addition, payload and power constraints severely limit the size, weight and processing power of the hardware to be carried …

Use Of Polyurethane Material Models For Simulating Leg-Form Impact In Different Explicit Finite Element Codes, Joe Hassan, Peter Schuster, G. Frederick

Mechanical Engineering

Compressible plastic foams are used throughout the interior and bumper systems of modern automobiles for safety enhancement and damage prevention. Consequently, modeling of foams has become very important for automobile engineers. To date, most work has focused on predicting foam performance up to approximately 80% compression. However, in certain cases, it is important to predict the foam under maximum compression, or 'bottoming-out.' This paper uses one such case-a thin low-density bumper foam impacted by a pedestrian leg-form at 11.1 m/s-to investigate the 'bottoming-out' phenomenon. Multiple material models in three different explicit Finite Element Method (FEM) packages (RADIOSS, FCRASH, and LS-DYNA) …

Redesigning Engineering Education, William W. Durgin, Edward A. Parrish

Office of the Provost Scholarship

In developing the PLAN, WPI sought to address concerns inherent to its then traditional curriculum that was rigid, unresponsive to differences among students, and was compartmentalized by independent departments so that intellectual growth was fragmented.

The PLAN was an entirely new and different educational program responsive to the needs of students and society while nurturing sensitivity to the ideas and values of our society. It included fundamental departures from the traditional elements of technical education including:
A. The achievement of competence rather than the accumulation of credits.
B. Individual freedom and responsibility in planning the program of study.
C. A …

Determination Of Bumper Styling And Engineering Parameters To Reduce Pedestrian Leg Injuries, Peter J. Schuster, Bradley Staines

Mechanical Engineering

The European Commission is proposing legislation aimed at reducing the severity of injuries sustained by pedestrians in the event of an impact with the front-end of a motor vehicle. One aspect of this proposed legislation is reducing the pedestrian's leg injuries due to contact with the bumper and frontal surfaces of a vehicle, assessed using a 'pedestrian leg impact device,' or 'leg-form.'

This proposed legislation presents the challenge of designing a bumper system which achieves the required performance in the leg-form impact-without sacrificing the bumper's primary function of vehicle protection during low-speed impacts. The first step in meeting this challenge …

The Restoration Of A Wwii Avenger Provides Projects For Wpi Students, Donald N. Zwiep, William W. Durgin, Nathan H. Mayo

Office of the Provost Scholarship

In 1970 WPI completely revised its traditional approach to engineering education. The resulting program, the WPI Plan, emphasized the use of projects as a distinctive process for achieving educational goals. Every student, as a degree requirement, had to successfully complete two major projects: one in a student's major field, the Major Qualifying Project (MQP) and the second, the Interactive Qualifying Project (IQP), which related science and technology to societal issues.

The IQP's related to the restoration of the WWII Avenger at Mayocraft, Inc. for the Collings Foundation in Stow, Massachusetts enabled the students working with the authors as advisors to …

Development Of A Mechatronics Design Studio, Sema E. Alptekin

Industrial and Manufacturing Engineering

Mechatronics is a combination of mechanics, electronics and information technology intended to raise the intelligence level and flexibility of products and devices. There is a need to develop programs and laboratories in Mechatronics to create an understanding of how new technologies influence the traditional methods of designing products and manufacturing systems. A model "Mechatronics Design Studio" has recently been developed to support the Mechatronics and Manufacturing Automation courses offered at Cal Poly's Industrial and Manufacturing Engineering Department. Laboratory experiments have been developed and several student projects have been completed. In this paper, an overview of the design studio and select …

Development Of Outcome Assessments At Wpi, William W. Durgin, Lance Schachterle

Office of the Provost Scholarship

The WPl PLAN, adopted by the WPl faculty in 1970, strongly anticipates current thinking about student outcomes assessments by structuring degree requirements that mandate that students demonstrate their ability to perform professional functions embodied in ABET Criteria 2000, especially Criteria 3 and 4. The WPI faculty has also practiced both student and self evaluations of these outcomes through respectively grades and peer review (both departmental and campus-wide) of student performance.

Preparing The Leaders For Mechatronics Education, Sema E. Alptekin

Industrial and Manufacturing Engineering

Mechatronics is the synergetic combination of precision mechanical engineering, electronic control and systems thinking in the design of products and processes. There is a need to develop interdisciplinary programs in Mechatronics that better prepare our graduates to design, build, and operate the products and systems of today and tomorrow. To address this need, National Science Foundation funded a project entitled "Preparing the Leaders for Mechatronics Education" undertaken by Cal Poly in 1995 - 1996. In this paper, the activities that took place during this two-year program is outlined. Several courses and course modules have already been developed and implemented by …

Distributed Activation Energy Model Of Heterogeneous Coal Ignition, John C. Chen

Mechanical Engineering

We present a model that simulates the conventional tube-furnace experiment used for ignition studies. The Distributed Activation Energy Model of Ignition accounts for particle-to-particle variations in reactivity by having a single preexponential factor and a Gaussian distribution of activation energies among the particles. The results show that the model captures the key experimental observations, namely, the linear increase in ignition frequency with increasing gas temperature and the variation of the slope of the ignition frequency with oxygen concentration. The article also shows that adjustments to the model parameters permit a good fit with experimental data.

Solute Nucleation And Growth In Supercritical Fluid Mixtures, Gregory T. Smedley, Gerald Wilemski, W. Terry Rawlins, David B. Oakes, Prakash Joshi, William W. Durgin

Office of the Provost Scholarship

This research effort is directed toward two primary scientific objectives: (1) to determine the gravitational effect on the measurement of nucleation and growth rates near a critical point and (2) to investigate the nucleation process in supercritical fluids to aid in the evaluation and development of existing theoretical models and practical applications. A nucleation pulse method will be employed for this investigation using a rapid expansion to a supersaturated state that is maintained for ≈ 1 ms followed by a rapid recompression to a less supersaturated state that effectively terminates nucleation while permitting growth to continue. Nucleation, which occurs during …

Modeling Of Macroscopic/Microscopic Transport Phenomena In Zeolite Crystal Solutions Under Microgravity Conditions, Andreas Alexandrou, Nikos A. Gatsonis, William W. Durgin, Albert Sacco, Jr.

Office of the Provost Scholarship

Crystals grown from special liquid solutions find important industrial applications. Most often the physics and chemistry of the growth processes are not well understood due to complex microscopic chemical and thermo-fluid phenomena. Microgravity could help elucidate these phenomena and allow the control of defect concentration and crystal size. We are proposing to study zeolites grown in silica solutions as a typical crystal growth system. By using macroscopic fluid dynamics, coupled with first-principle microscopic fluid physics and advanced particle simulations, we will study: (a) the effect of transport phenomena and nutrient flow under microgravity conditions along with (b) the nucleation process …

A Psychological Perspective On Service Segmentation Models: The Significance Of Accounting For Consumers' Perceptions Of Waiting And Service, Ziv Carmon, J. George Shanthikumar, Tali F. Carmon

Industrial and Manufacturing Engineering

We examine how service should be divided and scheduled when it can be provided in multiple separate segments. We analyze variants of this problem using a model with a conventional function describing the waiting cost, that is modified to account for some aspects of the psychological cost of waiting in line. We show that consideration of the psychological cost can result in prescriptions that are inconsistent with the common wisdom of queuing theorists derived according to the conventional approach (e.g., equal load assignments). More generally, our intention in this paper is to illustrate that aspects of the psychological cost of …

Circulation Measurements About A Rapidly Pitching Airfoil Using An Ultrasonic System, F. J. Weber, Jr., William W. Durgin, H. Johari

Office of the Provost Scholarship

An ultrasonic system was developed to measure the circulation about a sinusoidally pitching NACA 4418 airfoil. The system consisted of two opposing ultrasonic ranging modules arranged such that the differences between the sound propagation times in opposite directions could be related to the instantaneous circulation. For the stationary airfoil, the measured lift coefficient was within 5% of the tabulated data while the observed stall angle was 2° less than the tabulated value. Measured hysteresis loops verified the applicability of the ultrasonic system to the dynamic stall problem. Measured maximum lift coefficients increased linearly with reduced frequency up to a value …