Mechanical Engineering Commons^™

Trajectory Shaping Of Surface-To-Surface Missile With Terminal Impact Angle Constraint, S. Subchan

Makara Journal of Technology

This paper presents trajectory shaping of a surface-to-surface missile attacking a fixed with terminal impact angle constraint. The missile must hit the target from above, subject to the missile dynamics and path constraints. The problem is reinterpreted using optimal control theory resulting in the formulation of minimum integrated altitude. The formulation entails nonlinear, two-dimensional missile flight dynamics, boundary conditions and path constraints. The generic shape of optimal trajectory is: level flight, climbing, diving; this combination of the three flight phases is called the bunt manoeuvre. The numerical solution of optimal control problem is solved by a direct collocation method. The …

Effect Of Contact Time On Interface Reaction Between Aluminum Silicon (7% And 11%) Alloy And Steel Dies Skd 61, Bambang Suharno, Neni Octapiani Nurhayati, Bustanul Arifin, Sri Harjanto

Makara Journal of Technology

Effect of Contact Time on Interface Reaction between Aluminum Silicon (7% and 11%) Alloy and Steel Dies SKD 61. Die soldering (die sticking) is a defect of metal casting in which molten metal “welds” to the metallic die mold surface during casting process. Die soldering is the result of an interface reaction between the molten aluminum and the die material. Aluminum alloy with 7 and 11% silicon and SKD 61 die steel are the most common melt and die material used in aluminum die casting. This research is done to study the morphology and the characteristics of the formed AlxFeySiz …

Co2 Absorption From Its Mixture With Ch4 Or N2 Through Hollow Fiber Membrane Contactor Using Water As Solvent, Sutrasno Kartohardjono, Anggara Anggara, Subihi Subihi, Yuliusman Yuliusman

Makara Journal of Technology

CO2 Absorption from Its Mixture with CH4 or N2 through Hollow Fiber Membrane Contactor using Water as Solvent. Hollow fiber membrane contactors have been widely used as gas-liquid contactors recently such as in the CO2 absorption process from gas stream. This research aims to evaluate the effectiveness of hollow fiber membrane contactor to absorb CO2 from its mixture with CH4 or N2 using water through mass transfer and hydrodynamic tests. There are 3 membrane modules used in this research with shell diameter of 1.9 cm, length of 40 cm, outer fiber diameter of 2.7 mm and fiber number in the …

The Use Of Red Cabbage’S Anthocyanine Extract As A Photosensitizer On A Dye-Sensitized Nanocrystalline Tio2 Solar Cell, Akhiruddin Maddu, Mahfuddin Zuhri, Irmansyah Irmansyah

Makara Journal of Technology

The use of Red Cabbage’s anthocyanine extract as a photosensitizer on a Dye-Sensitized Nanocrystalline TiO2 Solar Cell. A solid-state dye-sensitized nanocrystalline TiO2 solar cell utilizing anthocyanin extract form red cabbage as photosensitizer was fabricated. The solar cell was formed in sandwich structure, which two electrodes sandwiching polymer electrolyte containing a redox couple (I-/I3 -). One of the electrodes, namely working electrode, TiO2 layer on TCO (transparent conducting oxide) coated glass substrate was sensitized with anthocyanin dye as electron donor in the system. Another electrode was a carbon sheet as a counter electrode. Gel electrolyte based on PEG (polyethylene glycol) containing …

The Potency Of Fire And Explosion Hazard On Premium Oil Storage Tank At Depot X 2007, Fatma Lestari, Warid Nurdiansyah

Makara Journal of Technology

The Potency of Fire and Explosion Hazard on Premium Oil Storage Tank at Depot X 2007. Premium oil storage tanks have fire and explosion risk because Premium oil is flammable liquid. Because of that, fire and explosion risk assessment on Premium oil storage tank at Depot X is needed as foundation to fire and explosion risk management, and comply with regulations. Method of this research is Dow’s Fire and Explosion Index. This research indicate that F&EI value for Premium oil storage tank is 118,82. Based on that F&EI value, level of risk at Premium oil storage tank is intermediate risk.

In-House Development Of Scheduling Decision Support Systems: Case Study For Scheduling Semiconductor Device Test Operations, Tali Freed, K. H. Doerr, T. Chang

Industrial and Manufacturing Engineering

Most manufacturing processes can benefit from an automated scheduling system. However;: the design of a fast, computerised scheduling system that achieves high-quality results and requires minimal resources is a difficult undertaking. Efficient .. scheduling of a semiconductor device test facility requires an information system that provides good schedules quickly. Semiconductor device testing-is the last stage of the long semiconductor manufacturing process, and therefore. is subjected to customer service pressures. The cost of an off-the-shelf computerised scheduling system may he prohibitive for many companies. In addition, many companies are taken aback by other characteristics of off-the-shelf scheduling systems, such as code …

Fabrication Of Functionally Graded 3a/5a Zeolites By Electrophoretic Deposition, X. Wang, E. A. Olevsky, E. Bruce, M. B. Stern, D. T. Hayhurst

Industrial and Manufacturing Engineering

Functionally graded zeolites of molecular sieve type 3A and 5A are deposited by electrophoretic deposition (EPD) from acetone suspension with 8% volume concentration of n-butylamine as particle charging agent. The EPD characteristics of both 3A and 5A suspensions are studied. Functionally graded zeolite 3A/5A deposits are obtained at 200 V DC. Energy dispersive X-ray dispersion (EDX) analysis results confirm the graded structure. The deposited zeolites are also analysed by scanning electron microscopy (SEM). The factors influencing the deposition process are discussed.

Commissioning High Performance Residences In Hot, Humid Climates, Florida Solar Energy Center, Ken Fonorow

FSEC Energy Research Center®

Since 2001, the authors have engaged several builders in the Gainesville, FL area to build over 500 high performance new energy efficient homes in multiple sub divisions. The builders keep building to increased levels of energy efficiency. Each home is individually designed, inspected, rated and commissioned for optimum performance. This paper summarizes the experiences to date with two production builders who have cost shared with the Building America program to deliver these outstanding results. Keys to success are commitment from the final decision maker; scopes of work for subcontractors with specific performance criteria; clear communication with the trades often accompanied …

Closing The Gap: Getting Full Performance From Residential Central Air Conditioners. Task 4.2-Develop New Climate-Sensitive Air Conditioner, Design, Construction, And Testing., Florida Solar Energy Center, Don B. Shirey Iii

FSEC Energy Research Center®

This study evaluated the performance of a prototype air conditioning system. The configuration of the prototype was based on detailed simulation results performed as part of this study. The results of the previously completed simulation indicated that energy-efficient, properly-ventilated homes in humid climates need equipment options or configurations that can provide a modest amount of additional dehumidification capacity while coordinating their operation with conventional cooling and ventilation systems. A prototype air conditioning system was constructed using currently available components and provides a method to independently control sensible (temperature) and latent (moisture) building loads. The prototype system was tested in both …

Damping And Fluidelastic Instability In Two-Phase Cross-Flow Heat Exchanger Tube Arrays, Joaquin Moran

Publications and Scholarship

An experimental study was conducted to investigate damping and fluidelastic instability in tube arrays subjected to two-phase cross-flow. The purpose of this research was to improve our understanding of these phenomena and how they are affected by void fraction and flow regime. The model tube bundle had 10 cantilevered tubes in a parallel-triangular configuration, with a pitch ratio of 1.49. The two-phase flow loop used in this research utilized Refrigerant 11 as the working fluid, which better models steam-water than air-water mixtures in terms of vapour-liquid mass ratio as well as permitting phase changes due to pressure fluctuations. The void …

On Internal Cone Cracks Induced By Conical Indentation In Brittle Materials, J. Yan, Anette M. Karlsson, X. Chen

Mechanical Engineering Faculty Publications

The conditions for cone cracks to develop due to a conical indentation are investigated. Axisymmetric numerical simulations, based on the finite element method, are conducted, assuming a linear-elastic, perfectly plastic material. A superposition scheme is employed to simulate a range of crack geometries, including various lengths and orientations. The results indicate that the class of cracks investigated is prone to develop internally in brittle materials. Based on a reversed analysis, a new technique is proposed for measuring the fracture toughness in bulk material and thick coatings through one simple indentation test when the cone crack appears.

The Effect Of Tibiofemoral Loading On Proximal Tibiofibular Joint Motion, Jacob Scott, Ho Lee, Wael Barsoum, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The human proximal tibiofibular joint (PTFJ) and its relationship to overall knee joint mechanics have been largely unexplored. This study describes force/displacement data from experiments done on four human cadaveric knee specimens and general conclusions obtained with the help of a statistical modeling technique. Specimens were rigidly affixed at the tibia to a force plate and the femur was attached to a custom made device allowing for manual load application. Motion of the fibular head was tracked relative to the tibial plateau by means of reflective markers and a high speed digital camera synchronized with the force plate data stream. …

Thermal Testing Of Building Insulation Materials, Eoghan Frawley, David Kennedy

Articles

This article explores the testing of building insulation materials and the development of a suitable testing apparatus.

Experimental Validation Of An Autonomous Control System On A Mobile Robot Platform, Timothy Mclain, Randall W. Beard, Wei Ran, J.-S. Sun

Faculty Publications

An autonomous control system designed for a non-holonomic wheeled mobile robot that is programmed to emulate a fixed-wing unmanned air vehicle (UAV) flying at constant altitude is experimentally validated. The overall system is capable of waypoint navigation, threat avoidance, real-time trajectory generation and trajectory tracking. Both the wheeled mobile robot experimental platform and the hierarchical autonomous control software architecture are introduced. Programmed to emulate a fixed-wing UAV flying at constant altitude, a non-holonomic mobile robot is assigned to follow a desired time-parameterised trajectory generated by a real-time trajectory generator to transition through a sequence of targets in the presence of …

High Temperature Heat Exchanger Project: Quarterly Progress Report July 1, 2007 Through September 30, 2007, Anthony Hechanova

Publications (NSTD)

• Ceramatec Sulfuric Acid Decomposer. The numerical model of a SiC ceramic coupon with two layers of microchannels was developed. Calculations of the factor of safety and probability of failure for the case of a straight channel were performed. Results for a pressure of 7.5 MPa were performed. The thermal and mechanical stress analyses of the Ceramatec HTHX and decomposer were completed.

• Bayonet Heat Exchanger. The thermal and mechanical stress analyses of the bayonet type HTHX and decomposer (Sandia design) were completed. Temperature profiles obtained from thermocouples measured from the Sandia experiments have been applied to the whole packed …

Repetitive Impact Response Of A Beam Structure Subjected To Harmonic Base Excitation, Elizabeth K. Ervin, Jonathan A. Wickert

Jonathan A. Wickert

This paper investigates the forced response dynamics of a clamped–clamped beam to which a rigid body is attached, and in the presence of periodic or non-periodic impacts between the body and a comparatively compliant base structure. The assembly is subjected to base excitation at specified frequency and acceleration, and the potentially complex responses that occur are examined analytically. The two sets of natural frequencies and vibration modes of the beam-rigid body structure (in its in-contact state, and in its not-in-contact state), are used to treat the forced response problem through a series of algebraic mappings among those states. A modal …

Acoustic Excitation Of Superharmonic Capillary Waves On A Meniscus In A Planar Microgeometry, Jie Xu, Daniel Attinger

Daniel Attinger

The effects of ultrasound on the dynamics of an air-water meniscus in a planar microgeometry are investigated experimentally. The sonicated meniscus exhibits harmonic traveling waves or standing waves, the latter corresponding to a higher ultrasound level. Standing capillary waves with subharmonic and superharmonic frequencies are also observed, and are explained in the framework of parametric resonance theory, using the Mathieu equation.

Planteamiento Y Programación De Trayectorias Para Labores De Ensamblaje Con El Robot Hidráulico De La Universidad De La Salle, Jairo José Barrera Pinto, Edgar Leonardo Calcetero Tintín

Ingeniería en Automatización

No abstract provided.

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

Nanoindentation in conjunction with piezoresponse force microscopy was used to study domain switching and to measure the mechanical properties of individual ferroelectric domains in a tetragonal BaTiO₃ single crystal. It was found that nanoindentation has induced local domain switching; the a and c domains of BaTiO₃ have different elastic moduli but similar hardness.Nanoindentationmodulus mapping on the a and c domains further confirmed such difference in elasticity. Finite element modeling was used to simulate the von Mises stress and plastic strain profiles of the indentations on both a and c domains, which introduces a much higher stress level than …

Integrated Piezoresistive Sensing For Feedback Control Of Compliant Mems, Robert K. Messenger

Theses and Dissertations

Feedback control of MEMS devices has the potential to significantly improve device performance and reliability. One of the main obstacles to its broader use is the small number of on-chip sensing options available to MEMS designers. A method of using integrated piezoresistive sensing is proposed and demonstrated as another option. Integrated piezoresistive sensing utilizes the inherent piezoresistive property of polycrystalline silicon from which many MEMS devices are fabricated. As compliant MEMS structures flex to perform their functions, their resistance changes. That resistance change can be used to transduce the structures' deflection into an electrical signal. This dissertation addresses three topics …

Effect Of Surface Roughness On Rate-Dependent Slip In Simple Fluids, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are used to investigate the influence of molecular-scale surface roughness on the slip behavior in thin liquid films. The slip length increases almost linearly with the shear rate for atomically smooth rigid walls and incommensurate structures of the liquid/solid interface. The thermal fluctuations of the wall atoms lead to an effective surface roughness, which makes the slip length weakly dependent on the shear rate. With increasing the elastic stiffness of the wall, the surface roughness smoothes out and the strong rate dependence is restored again. Both periodically and randomly corrugated rigid surfaces reduce the slip length and …

A Generalized Two-Dimensional Model To Reconstruct The Impact Phase In Automobile Collisions, Regis Agenor David

Theses and Dissertations

Automobile accident reconstruction has been facilitated by the development of computer based modules to allow evaluation of evidence gathered at the accident scenes. Although the computer modules are based in fundamental physical laws, an understanding of these laws by the user is required for proper application of the computer model in a given accident scenario. Vehicle collision analysis techniques generally separate the collision into three phases: pre-impact, impact, and post impact. The intent of the research is to provide a generalized model to reconstruct two dimensional impact problems in the area of accident reconstruction. There are currently two modeling techniques …

Optimal Control Of Class Of Non-Linear Plants Using Artificial Immune Systems: Application Of The Clonal Selection Algorithm, S. A. Panimadai Ramaswamy, Ganesh K. Venayagamoorthy, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

The function of natural immune system is to protect the living organisms against invaders/pathogens. Artificial Immune System (AIS) is a computational intelligence paradigm inspired by the natural immune system. Diverse engineering problems have been solved in the recent past using AIS. Clonal selection is one of the few algorithms that belong to the family of AIS techniques. Clonal selection algorithm is the computational implementation of the clonal selection principle. The process of affinity maturation of the immune system is explicitly incorporated in this algorithm. This paper presents the application of AIS for the optimal control of a class of non-linear …

Simulación Y Diseño De Un Mecanismo Automático Para Desplazamiento De Piezas En El Área De Pre-Tratamiento Químico De Partes Metálicas, Luis Carlos Romero Bonilla, Rodrigo Quiroga Contreras

Ingeniería en Automatización

No abstract provided.

Máquina Semiautomática Para Dosificado Y Empaque De Líquidos En Bolsa, Juan Carlos Vizcaino Aponte

Ingeniería en Automatización

Sistema semiautomático de dosificado y empaque en el cual el usuario cuenta con el tubo (bolsa) de empaque y necesita dosificar, empacar, sellar y cortar la dosis necesaria. Alimenta un tanque ubicado en la parte superior de la maquina por medio de bombeo de un tanque mas grande que abastece de material a la maquina. Luego por medio de una jeringa industrial se succiona la cantidad deseada de empaque para luego dosificarla por un tubo que dirige el liquido a la zona de empaque en donde un sistema de selle por medio de mordazas realiza la acción de sellar y …

Wigner Distribution Of A Transducer Beam Pattern Within A Multiple Scattering Formalism For Heterogeneous Solids, Goutam Ghoshal, Joseph A. Turner, Richard Weaver

Department of Engineering Mechanics: Faculty Publications

Diffuse ultrasonic backscatter measurements have been especially useful for extracting microstructural information and for detecting flaws in materials. Accurate interpretation of experimental data requires robust scattering models. Quantitative ultrasonic scattering models include components of transducer beam patterns as well as microstructural scattering information. Here, the Wigner distribution is used in conjunction with the stochastic wave equation to model this scattering problem. The Wigner distribution represents a distribution in space and time of spectral energy density as a function of wave vector and frequency. The scattered response is derived within the context of the Wigner distribution of the beam pattern of …

Electroelastic Effect Of Thickness Mode Langasite Resonators, Haifeng Zhang, Joseph A. Turner, J. S. Yang, J. A. Kosinski

Department of Engineering Mechanics: Faculty Publications

Langasite is a very promising material for resonators due to its good temperature behavior and high piezoelectric coupling, low acoustic loss, and high Q factor. The biasing effect for langasite resonators is crucial for resonator design. In this article, the resonant frequency shift of a thickness-mode langasite resonator is analyzed with respect to a direct current (DC) electric field applied in the thickness direction. The vibration modes of a thin langasite plate fully coated with an electrode are analyzed. The analysis is based on the theory for small fields superposed on a bias in electroelastic bodies and the first-order perturbation …

Effect Of Cold Work On The Tensile Properties Of 6061, 2024, And 7075 Al Alloys, D. Ortiz, M. Abdelshehid, R. Dalton, J. Soltero, R. Clark, M. Hahn, E. Lee, W. Lightell, B. Pregger, J. Ogren, P. Stoyanov, Omar S. Es-Said

Mechanical Engineering Faculty Works

Aluminum alloys 6061, 2024, and 7075 were heat treated to various tempers and then subjected to a range of plastic strain (stretching) in order to determine their strain limits. Tensile properties, conductivity, hardness, and grain size measurements were evaluated. The effects of the plastic strain on these properties are discussed and strain limits are suggested.

Evaluation Of Surface Residual Stresses In Friction Stir Welds Due To Laser And Shot Peening, Omar Hatamleh, Iris V. Rivero, Jeds Lyons

Iris V. Rivero

The effects of laser, and shot peening on the residual stresses in friction stir welds (FSW) has been investigated. The surface residual stresses were measured at five different locations across the weld in order to produce an adequate residual stress profile. The residual stresses before and after sectioning the coupon from the welded plate were also measured, and the effect of coupon size on the residual stress relaxation was determined and characterized. Measurements indicate that residual stresses were not uniform along the welded plate, and large variation in stress magnitude could be exhibited at various locations along the FSW plate. …

Platinum Nanoparticle Shape Effects On Benzene Hydrogenation Selectivity, Kaitlin M. Bratlie, Hyunjoo Lee, Kyriakos Komvopoulos, Peidong Yang, Gabor A. Somorjai

Kaitlin M. Bratlie

Benzene hydrogenation was investigated in the presence of a surface monolayer consisting of Pt nanoparticles of different shapes (cubic and cuboctahedral) and tetradecyltrimethylammonium bromide (TTAB). Infrared spectroscopy indicated that TTAB binds to the Pt surface through a weak C-HâââPt bond of the alkyl chain. The catalytic selectivity was found to be strongly affected by the nanoparticle shape. Both cyclohexane and cyclohexene product molecules were formed on cuboctahedral nanoparticles, whereas only cyclohexane was produced on cubic nanoparticles. These results are the same as the product selectivities obtained on Pt(111) and Pt(100) single crystals in earlier studies. The apparent activation energy for …