Mechanical Engineering Commons^™

Earth Systems Lesson Plan: Size And Forces Of The Solar System, Getaway Special Team 2010

Education and Outreach

No abstract provided.

Elementary And Middle School Science Lesson Plan: Solid, Liquid, Gas, What Is It?, Getaway Special Team 2010

Education and Outreach

No abstract provided.

Pole Arrangements That Introduce Prismatic Joints Into The Design Space Of Four- And Five-Position Rigid-Body Synthesis, David H. Myszka, Andrew P. Murray

Mechanical and Aerospace Engineering Faculty Publications

Although a general five-position, rigid-body guidance problem admits a discrete number of revolute–revolute (RR) dyads, this paper identifies arrangements of five task positions that result in a center-point curve. For these special arrangements, a one-dimensional set of revolute-prismatic (RP) dyads exist to achieve the task positions. Other five-position arrangements are identified where a one-dimensional set of prismatic-revolute (PR) dyads exist to achieve the task positions. For a general case of five task positions, neither PR nor RP dyads are possible. In a general case of four-position rigid-body guidance problems, a unique PR dyad and RP dyad exist. Four-position arrangements are …

Evaluation Of Bias Issues Within Regression-Based Inverse Modeling Methods Against Climate And Building Characteristics Using Synthetic Data, Florida Solar Energy Center, Jamie Cummings

FSEC Energy Research Center®

Typically, a model of the energy use of a building is created using the building's characteristics and climate information for its location. However, models of existing homes can be created using monitored energy and climactic data in a process called inverse modeling. Such a technique has potential for those seeking to evaluate the savings a home before and after a retrofit (Meier, Busch, & Conner, 1988).Several programs use an inverse modeling technique to model a home's energy use based on total home energy use, heating and cooling energy use, and indoor/outdoor temperature data from a home (Kissock, Haberl, & Claridge, …

Me-Em Enewsbrief, September 2010, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.

Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Point-Collocation Non-intrusive Polynomial Chaos (NIPC) method has been applied to a stochastic synthetic jet actuator problem used as one of the test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. The test case included the simulation of an actuator generating a synthetic jet issued into quiescent air. The Point-Collocation NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field due to the uniformly distributed uncertainty introduced in the amplitude and frequency of …

Modeling Acoustic Scattering From The Seabed Using Transport Theory, Jorge Quijano, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

Radiative Transfer (RT) theory has established itself as an important tool for electromagnetic remote sensing in parallel plane geometries with random distributions of scatterers, and most recently it has also been proposed as a model for the propagation of elastic waves in layered ocean sediments. In this work the capabilities of this model are illustrated, as the RT method is used to predict backscattering strength from laboratory models of random media. The RT model is characterized by its flexibility on accommodating scatterers in a broad variety of sizes, shapes, and acoustic contrast relative to the background media. Additionally, this formulation …

The Relation Between The Arterial Stress And Restenosis Rate After Coronary Stenting, Linxia Gu, Shijia Zhao, Aswini K. Muttyam, James M. Hammel

Mechanical & Materials Engineering Faculty Publications

Two commercially available stents (the Palmaz–Schatz (PS) and S670 stents) with reported high and low restenosis rates, respectively, have been investigated in this paper. Finite element models simulating the stent, plaque, and artery interactions in 3 mm stenosed right coronary arteries were developed. These models were used to determine the stress field in artery walls after stent implantation. The material properties of porcine arteries were measured and implemented in the numerical models. The stress concentration induced in the artery by the PS stent was found to be more than double that of the S670 stent. It demonstrated a good correlation …

State Space Model Of A Light Weight Flexible Telescope, Chi-Yeh Hsu

Master's Theses

The accuracy of optical telescope in the past was dominated by the construction of the telescope body and the precision of optical surface. This thesis fits into a larger project with a goal of controlling a flexible telescope in order to help a cheaper telescope achieve higher accuracy. In order to understand the internal motion of telescope, the goal of this thesis is to build a state space model of a two-degree-of-freedom telescope using a known star location as feedback. The model presented in this thesis may be used for the telescope simulation and the control design in the future. …

Sae Baja: Final Drive Gearbox, Michael Mccausland, Michael Watkins, Ian Masterson, Andrew Sommer

Mechanical Engineering

This paper presents the results of a manual transmission project for SAE Baja. A full engineering process is documented, including problem definition, scheduling, conceptualization, decision theory, synthesis, analysis, manufacturing, and testing. A comparison is made between existing and potential mechanical power train solutions. The final design is analyzed in dynamic simulations, AGMA stress, predicted FFT spectrums, and shifting rod buckling. A number of complicated parts are manufactured through investment casting and direct CNC machining. Issues in the final assembly have prevented the project from being fully realized, recommendations are made for future SAE Baja teams.

Performance Comparison Of Control Methods For Tankless Water Heaters, David P. Yuill, Andrew H. Coward, Gregor P. Henze

David Yuill

Tankless water heaters (TWH) have several advantages and disadvantages when compared with storage water heaters. One disadvantage is that the outlet temperature of the water is difficult to control. To address this problem, the authors apply seven different control approaches and con- duct experiments to test the effectiveness of each approach. The experiments are carried out on a commercially available electric TWH, using a test method and apparatus developed by the authors. The seven approaches include various configurations of feedback or feed-forward con- trol, or both. One fairly simple approach devised in this project combines feedback and feed-forward control. This …

Development Of A Pseudo-Uniform Structural Velocity Metric For Use In Active Structural Acoustic Control, Jeffery M. Fisher

Theses and Dissertations

Active control of sound and vibration fields has become an strong area of research over the past few decades. In regards to the active control of acoustic radiation from vibration fields, known as active structural acoustic control (ASAC), there have been many different methods employed to understand structural and acoustic relationships and to control vibrations to limit the acoustic radiation. With active sound field control, sensors, usually microphones, need to be dispersed in the sound field, or an array of microphones must be placed directly in the sound field which, in many cases, uses up too much space for practical …

Cathode Polarizations Of A Cathode-Supported Solid Oxide Fuel Cell, Kevin Huang, Alessandro Zampieri, Martin Ise

Faculty Publications

The concentration, activation, and total polarizations of the cathode in a cathode-supported solid oxide fuel cell (SOFC) were theoretically and experimentally investigated. In the theoretical analysis, the exchange current density of the charge transfer was considered to be dependent on the P_O2 determined by the preceding O₂ diffusion, resulting in an interrelationship between activation and concentration polarizations. The established nonlinear polarization equations were then applied to solve the key parameters with area specific resistances and overpotentials of the polarizations experimentally measured by electrochemical impedance spectroscopy on an operating cathode-supported SOFC. To ensure the consistency and meaningfulness of …

Nanofibers And Nanoparticles From The Insect-Capturing Adhesive Of The Sundew (Drosera) For Cell Attachment, Mingjun Zhang, Scott C. Lenaghan, Lijin Xia, Lixin Dong, Wei He, William R. Henson, Xudong Fan

Faculty Publications and Other Works -- Mechanical, Aerospace and Biomedical Engineering

Background

The search for naturally occurring nanocomposites with diverse properties for tissue engineering has been a major interest for biomaterial research. In this study, we investigated a nanofiber and nanoparticle based nanocomposite secreted from an insect-capturing plant, the Sundew, for cell attachment. The adhesive nanocomposite has demonstrated high biocompatibility and is ready to be used with minimal preparation.

Results

Atomic force microscopy (AFM) conducted on the adhesive from three species of Sundew found that a network of nanofibers and nanoparticles with various sizes existed independent of the coated surface. AFM and light microscopy confirmed that the pattern of nanofibers corresponded …

Passive Variable Compliance For Dynamic Legged Robots, Kevin C. Galloway

Publicly Accessible Penn Dissertations

Recent developments in legged robotics have found that constant stiffness passive compliant legs are an effective mechanism for enabling dynamic locomotion. In spite of its success, one of the limitations of this approach is reduced adaptability. The final leg mechanism usually performs optimally for a small range of conditions such as the desired speed, payload, and terrain. For many situations in which a small locomotion system experiences a change in any of these conditions, it is desirable to have a tunable stiffness leg for effective gait control.

To date, the mechanical complexities of designing usefully robust tunable passive compliance into …

On Macroscopic Constitutive Relations And Microstructure Evolution In Multi-Scale Viscoplastic Composites, Michalis Agoras

Publicly Accessible Penn Dissertations

The determination of the effective or macroscopic properties of composite materials from the corresponding local properties of the constituent phases and the underlying sub-structure constitutes the fundamental problem in Mechanics of Composites. This problem is motivated from the remarkable physical observation that the constitutive properties of these materials appear to be homogeneous or uniform at the length scale of practical applications, despite the sharp variation of their local properties at the length scale of the heterogeneity and the fairly complex spatial distribution of their phases. This dissertation is concerned with the macroscopic mechanical properties of “multi-scale” viscoplastic composites, i.e., composite …

Freeze Extrusion Fabrication Of 13-93 Bioactive Glass Scaffolds For Bone Repair, Tieshu Huang, Nikhil D. Doiphode, M. N. Rahaman, Ming-Chuan Leu, B. Sonny Bal, D. E. Day

Materials Science and Engineering Faculty Research & Creative Works

There is an increasing demand for synthetic scaffolds with the requisite biocompatibility, internal architecture, and mechanical properties for the bone repair and regeneration. In this work, scaffolds of a silicate bioactive glass (13-93) were prepared by a freeze extrusion fabrication (FEF) method and evaluated in vitro for potential applications in bone repair and regeneration. The process parameters for FEF production of scaffolds with the requisite microstructural characteristics, as well as the mechanical and cell culture response of the scaffolds were evaluated. After binder burnout and sintering (60 min at 700°C), the scaffolds consisted of a dense glass network with interpenetrating …

Effect Of Different Graphite Materials On Electrical Conductivity And Flexural Strength Of Bipolar Plates Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Graphite is an excellent material for bipolar plates used in Proton Exchange Membrane (PEM) fuel cell due to its great chemical resistance, but the brittle nature makes it difficult to manufacture. Selective Laser Sintering (SLS) based on layer-by-layer manufacturing technology can fabricate graphite bipolar plates with complex gas flow channels. To improve the performance of bipolar plates including electrical conductivity and flexural strength, different graphite materials (natural graphite, synthetic graphite, carbon black, and carbon fiber) were investigated to fabricate test samples. These samples then went through post processing including carbonization and infiltration. The results show that bipolar plates with electrical …

Laser Based Rapid Manufacturing Of Metallic Gas Diffusion Layers For Pem Fuel Cells, Gargi Tandra, Todd E. Sparks, Shyam Barua, Nikhil P. Kulkarni, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Gas Diffusion layers (GDL’s) are an essential component of Polymer Electrolyte Membrane Fuel cells (PEMFC’s) which aid in thermal & electrical conductivities, water management and act as backup layers for the membrane electrode assemblies. This paper summarizes the effort to prototype metallic GDL designs using a miniature laser deposition system developed at Missouri University of Science & Technology. The pore sizes are controlled by masking the diverging laser beam using stainless steel masks of varying sizes and shapes. The through pore feature and further treatment of the GDL’s for hydrophobicity reduces the water management issue and thereby increases the performance …

Multi-Axis Planning System (Maps) For Hybrid Laser Metal Deposition Processes, Frank W. Liou, Jianzhong Ruan, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper summarizes the research and development of a Multi-Axis Planning System (MAPS) for hybrid laser metal deposition processes. The project goal is to enable the current direct metal deposition systems to fully control and utilize multi-axis capability to make complex parts. MAPS allows fully automated process planning for multi-axis layered manufacturing to control direct metal deposition machines for automated fabrication. Such a capability will lead to dramatic reductions in lead time and manufacturing costs for high-value, low-volume components with high performance material. The overall approach, slicing algorithm, machine simulation for planning validation, and the planning results will be presented.