Mechanical Engineering Commons^™

Programming The Bistable Dynamic Vibration Absorbers Of A 1d-Metastructure For Adaptive Broadband Vibration Absorption, Shantanu H. Chavan

Dissertations, Master's Theses and Master's Reports

This research addresses a critical challenge in structural engineering—achieving comprehensive vibration control and energy dissipation in meta-structures. Departing from the limitations of passive structures with fixed bandgaps, we propose an innovative approach utilizing active meta-structures capable of dynamically tuning their bandgaps. The primary goal is to introduce an efficient method for programming meta-structures with multiple variable bandgaps, thereby enabling effective vibration attenuation across a broad frequency spectrum.

The methodology involves transforming passive resonators into bistable adaptable Dynamic Vibration Regulators (DVRs) through a sophisticated switching mechanism. This adaptation sets the stage for numerous unique combinations by independently switching each resonator. A …

Study Of Eco-Driving And Charging Planning In Connected And Automated Vehicles Environment, Pradeep Bhat

Dissertations, Master's Theses and Master's Reports

In this dissertation, the development of eco-driving and charging planning algorithms in the connected and automated vehicle environment (CAV) are presented. CAV technologies provide opportunities for potential energy savings and efficiency improvement of transportation networks, which are explored through multiple research tasks in this study.

The objective of the first study presented in Chapter 2 is to reduce vehicle dynamic losses and required tractive force while completing trip distance within a given travel time. Sequential Quadratic Programming method is employed for this nonlinearly constrained optimization problem. The validation result illustrates the benefits of optimal velocity trajectories. The objective of the …

Correlation Of And Development Of Procedure To Use A Resonant Plate With Mechanical Excitation For Shock Testing Small-To-Medium Size Spacecraft And Provide Aerospace Shock Analysis And Testing Guidelines, Monty Kennedy

Dissertations, Master's Theses and Master's Reports

In the aerospace industry it is known that performing shock analysis and testing on spacecraft is difficult to do mostly because shock loads create a very short duration shock wave transient that can have high acceleration peak levels (1,000-5,000 g) and wide frequency content (100-10,000 Hz). FE (finite-element) shock analysis is difficult because implicit linear FE software commonly used for most vibration analysis in aerospace does not account for shock wave propagation, reflection, and attenuation that occurs based upon the distance from the shock source at the base of the spacecraft and the attenuations that occurs through mechanical joints. Spacecraft …

Multi-Chamber Silencer Composed Of Screw-Perforated Tubes And Straight-Perforated Tubes, Tian-Syung Lan, Min-Chie Chiu

Journal of Marine Science and Technology–Taiwan

The use of silencers to reduce noise is mandatory due to severe hearing damage caused by high venting noise in the engine room of ocean-going vessels. While straight and perforated tubes have been used as acoustical elements in traditional silencer design, studies have shown that the acoustical design still requires improvement. To enhance acoustical efficiency, the use of multi-chamber mufflers is proposed composed of screw and perforated tubes. Additionally, a mathematical finite element model built for acoustical simulation using the COMSOL program expedites the analysis of silencers with complicated acoustical elements. A sensitivity analysis of transmission loss concerning the geometric …

Rapid Species Identification Of Meretrix Lusoria And Three Other Meretrix Clams Using Pcr And Rflp Analysis Of The Mitochondrial Coii Gene., Chia-Hsuan Sung, Liang-Jong Wang, Chang-Wen Huang

Journal of Marine Science and Technology–Taiwan

Meretrix clams are among the most economically important species of bivalves in Eastern Asia and Taiwan. In the past, the identification of these hard clams depended on the shell morphology; however, species identification based on shell markings and shapes confuses the taxonomy of the Meretrix genus. The DNA molecular information is useful and can easily identify them accurately and quickly, especially the sequence of mitochondrial DNA. In this study, a PCR method to analyze the mitochondrial cytochrome c oxidase II (COII) gene was developed to rapidly identify of M. lusoria, M. lamarckii, M. lyrata and M. petechialis. Four different species …

Bearing Capacity Factor Characteristics Of Footings On Double-Layered Cohesive Soils, Chao-Ming Chi, Zheng-Shan Lin, Yu-Shu Kuo

Journal of Marine Science and Technology–Taiwan

In this study, the bearing capacity of a surface foundation resting on a double-layered cohesive soil profile was investigated by applying a rotational mechanism and finite-difference numerical simulations. The bearing capacity factor behaviors of a surface footing on double-layered cohesive soils can be classified and illustrated using a characteristic chart. Depending on the soil strata strength ratio and normalized layer thickness, the soil-foundation system can be in the squeezing, factor-increasing, factor-decreasing, or constant factor zones. The results indicated that the trend of the curves in the characteristic chart computed from the asymmetric failure mechanism was in accordance with that of …

Research On Ice Resistance Of Ships Sailing In Floating Ice Floe, Zhixin Xiong, Xinyuan Wu, Yang Li

Journal of Marine Science and Technology–Taiwan

To study the ice resistance of ships in areas with floating ice, the Xuelong 2 icebreaker was simulated. A floating-ice model was established using the discrete-element method, and an ice particle array was generated using MATLAB. The effects of ice coverage and speed on ice drag were studied From the numerical simulation results, it can be seen that there is a certain trend in ice resistance under different ice coverage ranges, which changes with the change of speed.By comparing with the empirical formula and the numerical value of the ship model test, this numerical simulation results are relatively accurate.It also …

The Pre-Processing Of Wt Blade Images By Ss And Bilateral Filter With Machine Learning Frameworks, Joy Iong-Zong Chen, Chien-Yeh Lee, Wien-Chieh Lo

Journal of Marine Science and Technology–Taiwan

This paper discusses the motivation behind turbine migration and addresses the challenges of using NN (neural network) computing systems. Moreover, it focuses on high-dimensional data from WT (wind turbine) blades. The three key aspects addressed in this study are turbine migration, overfitting, and strict feature selection. To evaluate the performance of the machine learning system, the study considers the characteristics of WT blades, specifically the similarity in blade color and the differences in shape. The authors apply pre-processing techniques, in particular a bilateral filter, in conjunction with the SS (selective synthesizer) of blade fouling patterns. The SS method adopts the …

การพัฒนาชุดทดสอบความล้าดัดสำหรับตะไบทางทันตกรรม, ธีรเมธ เกศโร

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์นี้มุ่งเน้นไปที่การออกแบบและสร้างชุดทดสอบความล้าดัดสำหรับตะไบทางทันตกรรม ที่สามารถวัดจำนวนรอบที่ทำให้เสียหายของตะไบได้โดยตรงผ่านการวิเคราะห์สัญญาณในระบบควบคุมวงปิดของมอเตอร์ โดยที่ไม่จำเป็นต้องใช้วิธีดั้งเดิม ซึ่งเป็นการคำนวณหาจำนวนรอบที่ทำให้เสียหาย ภายใต้สมมติฐานที่ว่าอัตราเร็วในการหมุนของตะไบคงที่ ทั้งที่ในทางปฏิบัติ ตะไบอาจจะไม่ได้หมุนด้วยอัตราเร็วคงที่เสมอไป นอกจากนี้ ในวิทยานิพนธ์ ก็ได้มีการตรวจสอบความน่าเชื่อถือหรือการใช้งานได้ของชุดทดสอบที่ถูกพัฒนาขึ้นมาในแง่มุมต่าง ๆ ผ่านการนำไปทดสอบกับชิ้นงานจริง โดยตะไบรุ่น Zenflex จำนวน 100 ชิ้น ได้ถูกนำไปทดสอบในคลองรากฟันเทียมทั้งหมด 5 รูปร่างที่มีรัศมีความโค้งและมุมโค้งแตกต่างกัน ณ อุณหภูมิห้องและอุณหภูมิร่างกาย ผลการทดสอบแสดงให้เห็นว่า ชุดทดสอบสามารถทำให้ตะไบเสียหายจากความล้าดัดได้ เนื่องจากบนพื้นผิวแตกหักและด้านข้างจุดแตกหักพบลักษณะที่เป็นเอกลักษณ์ของกลไกการเสียหายล้า แต่ไม่พบร่องรอยจากการเสียหายบิด และชุดทดสอบก็สามารถควบคุมให้ตะไบแตกหักที่ตำแหน่งใกล้เคียงกันได้ ไม่ว่าตะไบเหล่านั้นจะถูกทดสอบภายใต้เงื่อนไขใด เนื่องจากตะไบส่วนที่หักมีความยาวใกล้เคียงกันทั้งหมดและใกล้เคียงกับค่าที่ออกแบบไว้ ส่วนแนวโน้มของจำนวนรอบที่ทำให้เสียหายเมื่อแปรค่าตัวแปรต่าง ๆ ในการทดสอบไป ก็มีความสอดคล้องกับแนวโน้มเดียวกันจากงานวิจัยที่ผ่านมา จึงอาจกล่าวได้ว่า ชุดทดสอบมีความน่าเชื่อถือเพียงพอ ในฐานะชุดทดสอบความล้าดัดสำหรับตะไบ นอกจากนี้ จำนวนรอบที่ทำให้เสียหายจากชุดทดสอบหลัก ก็ได้ถูกนำมาเปรียบเทียบกับจำนวนรอบที่ทำให้เสียหายที่คำนวณได้จากวิธีดั้งเดิม โดยข้อมูลที่นำมาคำนวณจะถูกเก็บควบคู่ไปกับการทดสอบหลัก ซึ่งผลปรากฏว่า จำนวนรอบที่ทำให้เสียหายจากวิธีดั้งเดิมมีค่าสูงกว่าจำนวนรอบที่ทำให้เสียหายจากชุดทดสอบหลักที่วัดรอบที่ตะไบหมุนได้โดยตรง

Development Of Corn Kernel-Based Biocomposite Films For Food Packaging Applications, Swastika Bera

Electronic Theses and Dissertations

Most of the current and active food packaging resources and methods are nonbiodegradable and nonrenewable therefore harmful to the environment. Due to this, alternate sources of food packaging materials are in high demand. In this study, a bio-composite film has been developed, with Corn kernel powder as fiber reinforcement which is mixed with gelatin, and lignin two biopolymers as the matrix. The effect of Corn Kernel (CK) reinforcement on the Gelatin/Lignin (G/L) matrix on mechanical and barrier properties has been studied. CK has shown great potential as reinforcement to natural polymer, gelatin, and lignin (G/L) for food packaging applications as …

Perceptual Anthropomorphic Walking Robot Platform For Navigation In Unstructured And Undifferentiated Environments, Luige Vladareanu, Mihai Rădulescu, Marius Pandelea, Hongbo Wang, Florentin Smarandache, Yongfei Feng, Ionel-Alexandru Gal, Alexandra C. Ciocîrlan

Branch Mathematics and Statistics Faculty and Staff Publications

This scientific presentation studies the VIPRO Platform for control of Anthropomorphic Walking Robots (AWR), the architecture control system of the SiMeLA MP robot motion, and shows several experimental results.

Nebraska Summary: S1256 Fendt 722 Vario Gen7, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Investigation Of Oxidation And Corrosion Resistance Of Ni-Based Alloys And Stainless Steels Under Co2 Environments At Elevated Temperatures, Spencer Roy Fultineer

Graduate Theses, Dissertations, and Problem Reports (ETD)

High mechanical strength integrity, high robustness towards oxidation, and high resistance to carburization under CO2 environments at elevated temperatures are usually required for metallic systems that are employed for power generation. INCONEL 625 is a nickel-based superalloy that started development in the 1950s. This material was designed with the distinct purpose of use in high-temperature and high-pressure systems. While various materials possess the physical properties to handle these conditions, the creation of IN625 addresses the need for a material to withstand the highly corrosive properties of these kinds of environments. In order to evaluate the oxidation and corrosion resistance of …

Development Of Inconel 718f And Inconel 718e Powders For Parts Manufacturing Utilizing Binder Jet Three-Dimensional Printing And Compressed Pellet Methods, Duncan Eric Manor Ii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Alloy Inconel 718 is a Ni based superalloy used for high temperature applications including turbine blades, turbocharger rotors and nuclear reactors. Inconel 718 is a popular commercial atomized powder that has limitations in performance for use in additive manufacturing applications due to poor part quality and efficiency of current fabrication methods. Developing new compositions and additive manufacturing (AM) methodologies of IN718 is critical to improve the quality and the efficiency of IN718 parts manufacturing. Developing new additive manufacturing methodology that produces higher quality parts made of IN718 as compared to current methods has the potential to greatly impact industry, academia, …

A Comparative Analysis Of Coastdown Testing Methods From An Electric Drive Unit Engagement Perspective Using A Student-Designed Parallel Hybrid Electric Vehicle, Dawson Everett Dunnuck

Graduate Theses, Dissertations, and Problem Reports (ETD)

Coastdown testing and road load determination are pivotal parts of the automotive design process. Vehicle manufacturers and independent companies perform and analyze road loads determined through a coastdown or similar method to determine a vehicle’s road load for modeling and EPA certification. For a traditional coastdown, the vehicle’s drivetrain must be disconnected through a clutch between the engine and the transmission while traveling at a high rate of speed to place the vehicle in neutral. This changes for hybrid and electric vehicles. Some hybrid, and most electric, vehicles delivered to customers do not have this clutch action to grant the …

Design And Manufacture Of An Aerodynamic Body That Meets Scaling Law Requirements And Survives Severe G-Load Environment For Free-Flight Testing, Anthony R. Gonzalez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Design and Manufacture of an Aerodynamic Body that Meets Scaling Law Requirements and Survives Severe G-load Environment for Free-Flight Testing

Anthony Gonzalez

Developing scale models to test functionality and ascertain aerodynamic properties is critical before manufacturing full-size products. Through dimensional analysis and similitude, engineers create scale models to test any parameter of interest. This research aims to design a scale model of an aerodynamic body for repeated free-flight testing. The Froude number is the dominant scale model law used to determine the geometric, mass, and inertia scaling laws. A critical requirement for this research is that the model should be …

Material Characterization Of Thermoplastic Polyurethane (Tpu) And Thermoplastic Elastomers (Tpe) For Development Of 3d-Printed Surrogate Organs For Medical Training, Anastasia Elizabeth Lucci

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cadaveric specimens are a necessary, albeit limited, resource for training medical students on basic surgical skills. The availability of surrogate 3D-printed organs would readily allow access to resources that could reduce or potentially eliminate the need for cadaveric specimens or, at a minimum, provide students the opportunity to practice with 3D-printed surrogates before transitioning to those specimens. This research focuses on determining which thermoplastic material most closely mimics mechanical properties such as hardness and stiffness of human organs and allows 3D printing surrogate organs to be used as safe, educational tools. Relatively “soft” materials such as thermoplastic polyurethanes (TPU) and …

Finite Element Modeling And Analysis Of Breech Face Impressions, James A. Hamilton

Graduate Theses, Dissertations, and Problem Reports (ETD)

Finite element analysis (FEA) is a technique which has not been widely used in Forensic Science in general and firearms examination in particular. The general utility of FEA was assessed by the simulation of scenarios commonly encountered during the investigation of firearm related crimes. As a test, simulations included the perforation of a windshield and sheet metal with a 9 mm projectile, the development of pseudo subclass characteristics during the manufacturing of a breech face, and the impact of a projectile with another projectile in air and with a solid body. Results from the simulations were compared to projectiles and …

Biologically – Plausible Load Feedback From Dynamically Scaled Robotic Model Insect Legs, William Zyhowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

Researchers have been studying the mechanisms underlying animal motor control for many years using computational models and biomimetic robots. Since testing some theories in animals can be challenging, this approach can enable unique contributions to the field. An example of a system that benefits from this modeling and robotics approach is the campaniform sensillum (CS), a kind of sensory organ used to detect the loads exerted on an insect's legs. The CS on the leg are found in groups on high-stress areas of the exoskeleton and have a major influence on the adaptation of walking behavior. The challenge for studying …

Numerical Simulation Of The Donor-Assisted Stir Material For Friction Stir Welding Of Aluminum Alloys And Carbon Steel, Joseph Maniscalco, Abdelmageed A. Elmustafa, Srinivasa Bhukya, Zhenhua Wu

Mechanical & Aerospace Engineering Faculty Publications

In this research effort, we explore the use of a donor material to help heat workpieces without wearing the tool or adding more heat than necessary to the system. The donor material would typically be a small piece (or pieces) of material, presumably of lower strength than the workpiece but with a comparable melting point. The donor, a sandwich material, is positioned between the tool head and the material to be welded, where the tool initially plunges and heats up in the same manner as the parent material that is intended for welding. The donor material heats up subsequent to …

Numerical Study Of The Time-Periodic Electroosmotic Flow Of Viscoelastic Fluid Through A Short Constriction Microchannel, Jianyu Ji, Shizhi Qian, Armani Marie Parker, Xiaoyu Zhang

Mechanical & Aerospace Engineering Faculty Publications

Electroosmotic flow (EOF) is of utmost significance due to its numerous practical uses in controlling flow at micro/nanoscales. In the present study, the time-periodic EOF of a viscoelastic fluid is statistically analyzed using a short 10:1 constriction microfluidic channel joining two reservoirs on either side. The flow is modeled using the Oldroyd-B (OB) model and the Poisson-Boltzmann model. The EOF of a highly concentrated polyacrylamide (PAA) aqueous solution is investigated under the combined effects of an alternating current (AC) electric field and a direct current (DC) electric field. Power-law degradation is visible in the energy spectra of the velocity fluctuations …

Thermotrophy Exploratory Study, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The question of whether environmental heat energy could be utilized as a source of energy for biological metabolism is the center of this exploratory research. In 1979, this author postulated a hypothesis for the existence of thermotrophs that could isothermally utilize environmental heat energy as a source of their energy on Earth. According to this hypothesis, the thermotrophs could be the first primitive forms of life in the early Earth environment. The chemotrophs and phototrophs that we currently are all well familiar with might have been evolved somehow from the primitive thermotrophs. Furthermore, all the organisms currently regarded as the …

Jet Noise Reduction: A Fresh Start, Christopher K. Tam, Fang Q. Hu

Mathematics & Statistics Faculty Publications

Attempts to reduce jet noise began some 70 years ago. In the literature, there have been many publications written on this topic. By now, it is common knowledge that jet noise consists of a number of components. They possess different spectral and radiation characteristics and are generated by different mechanisms. It appears then that one may aim at the suppression of the noise of a single component instead of trying to reduce jet noise overall. The objective of the present project is to reduce large turbulence structures noise. It is the most dominant noise component radiating in the downstream direction. …

Pneumatic Latched Demultiplexer Circuit For Controlling Multi-Actuator Soft Robots, Arsh Noor Amin

Master’s Theses

This thesis presents a novel method for controlling multi-actuator soft robots using pneumatic latched demultiplexer circuits implemented with monolithic membrane valves. The pneumatic circuits are designed to address the problems of heavy dependence on hard electrical components and lack of feasible multi-actuator soft robotic systems that limit the potential applications of soft robotics. The proposed pneumatic demultiplexers reduce the number of solenoid valves and electrical components required to drive soft robotic systems, making soft robot control mechanisms more compliant, scalable, and versatile. The thesis demonstrates the design, fabrication, and testing of 4-bit and n-bit pneumatic demultiplexer circuits that can control …

Recycling Metal Chips Into Usable Materials, Alex Mortensen, Ben Mortensen

Williams Honors College, Honors Research Projects

This report entails the scope, design considerations, and plans for creating a metal chip converter into metal briquettes. The construction is a set of machines with multiple processes to make the conversion happen. The process includes washing fine metal chips, drying them off, compressing them, and melting them down into usable briquettes. This project is intended to make a simple process to recycle metal chips into usable material for reuse. The project's objective is to reduce the costs of storage and recycling waste by offering a solution to recycle it into materials the shop can reuse.

The Passing Board, John Fitzgerald

Williams Honors College, Honors Research Projects

For my Honors Research Project I am taking a more personal route and looking to solve a childhood question/issue by designing a board that is small and easy to transport while also giving the best bounce pass possible. My proposed project would be a board that a soccer player can play a bounce pass onto and receive the ball from. The base of this design sounds simple enough, however, I would like to implement a way that the board can be adjusted to alter the angle of return of the soccer ball after the bounce. I also want to design …

Impact Of Lubricant In The Performance Of Variable Speed Heat Pumps Working With R290, Rubén Ossorio, Emilio Navarro-Peris, Riley Barta

School of Mechanical Engineering Faculty Publications

Modulating the speed of the compressors and adapting its capacity to the required load has led to a decrease in the annual energy consumption in many applications. However, in the compressor, having adequate lubrication at low speeds usually implies discharging too much lubricant at higher speeds. Although necessary for compressor operation, lubricating oil acts as a contaminant in the rest of the system. Consequently, manufacturers have to consider the oil circulation rate (OCR), as it limits the speed range of the compressor. In a previous study, a compressor was tested over its speed range (30 – 110 Hz), working with …

Wave-Powered Batch Reverse Osmosis Buoy, Austin Howse, Camden Frieling, Cooper Ford, Imaan Qazilbash, Joel Veihl, Mariya Savchenko, Ryan Vulich, Sultan Alnajdi, Abhimanyu Das, Antonio Esquivel-Puentes, Ali Naderi Beni, David M. Warsinger, José Garcia-Bravo

School of Mechanical Engineering Faculty Publications

As populations grow across the world, the availability of freshwater at a reasonable cost has become a growing concern to many nations. An estimated 1.1 billion people do not have access to safe drinking water [5]. Many of these areas also exist in coastal communities which get burdened by severe weather storms. During these occasions, access to clean drinking water drastically decreases. Combining this with the potential for ocean energy, access to clean drinking water can be derived with a potential solution. The ocean contains abundant resources that comprise of untapped wave-powered energy, unharvested salt water to be turned potable, …

Studies On Non-Transition Metal Substitution To Ab2 Metal Hydride Alloys For Battery Application, Shiuan Chang

Wayne State University Dissertations

Nowadays, multiphase transition metal-based AB2 metal hydride alloys and the rare-earth metal-based AB5 alloys (currently used in consumer NiMH batteries) are used as negative electrodes in NiMH batteries. It is of great interest to explore the possibility of significantly improving NiMH battery performance to compete with Li-ion batteries. In this area, the effect of dopant elements from Group-IA, -IIA, -IIIA non-transition metal family has not been thoroughly studied. In this study, lithium, magnesium, and boron (a metalloid considered metal in this study) were chosen as modifiers in the C14-phase predominant AB2 alloy by different dopant concentrations and synthesis methods, doping …

Optical Diagnostics Of Hydrocarbon Fuel Autoignition Using The Corrected Filtered Natural Emission Of Species Technique, Maysam Molana

Wayne State University Dissertations

The gas temperature and concentration of carbon monoxide and carbon dioxide of a hydrocarbon fuel mixture were measured using a rapid compression machine by applying a modern optical diagnostics methodology called the corrected filtered natural emission of species (C-FNES) technique. This technique uses a correction factor that includes all of the experimental and simulation errors and uncertainties into the measurements. To ensure the robustness of the proposed technique, the effect of temperature and pressure on the measured data was investigated extensively. To this end, a pentane inert mixture was tested in a wide range of operation conditions: six compressed gas …