Mechanical Engineering Commons^™

The Temperature Dependent Mechanical Response Of M250 Maraging Steel And Its Implications On Wire Arc Additive Manufacturing, Frank M. Brinkley Iii

Theses and Dissertations

Wire-arc additive manufacturing (WAAM) is becoming increasingly common for large scale additive manufacturing (AM) applications because of its high deposition rate (2-3 kg/hr.). The rapid temperature changes and subsequent evolution of mechanical properties during AM can lead to large distortion and residual stresses. Finite element modeling of the AM process shows promise to minimize part distortion and residual stresses through improved path planning and process parameter optimization. However, accurate material properties of M250 before and after heat treatment are needed to properly characterize the property evolution from annealed to AM, to aged. Due to limited data on annealed M250, this …

Ferrous Alloy Manufacturing For The Martian Surface Through In-Situ Resource Utilization With Ionic Liquids Harvested Iron And Bosch Process Carbon, Blake C. Stewart

Theses and Dissertations

As research continues for the habitation of the Lunar and Martian surfaces, the need for materials for construction of structural parts, mechanical components, and tools remains as a major milestone. The use of in-situ resource utilization (ISRU) techniques is critical due to the financial, physical, and logistical burdens of sending supplies beyond low-Earth orbit. The Bosch process is currently in development as a life support system at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to regenerate oxygen (O2) from metabolic carbon dioxide (CO2) with the byproduct of elemental carbon (C). The Bosch process presents a …

An Investigation Into The Velocity-Dependence Of The Coefficient Of Friction Between Concrete And Maraging Steel, Trace A. Duncan

Theses and Dissertations

This work investigates the velocity-dependent coefficient of friction between concrete and 300 Maraging steel over short displacements. A modified torsional Hopkinson bar is utilized for rotating thin-walled steel rings in contact with a concrete disk under static precompression. Rotational velocity is varied between tests to determine the velocity dependence of the friction coefficient. Normal force is varied between certain tests to determine the pressure dependence of the friction coefficient between the concrete and steel. Three different types of concrete are tested to deduce any composition effect on the friction coefficient. Dry and greased conditions’ impact on the friction coefficient are …

Biodiesel Production From A Non-Edible Source Of Royna (Aphanamixis Polystachya) Oil, Md. Wasikur Rahman, Asim Kumar Mondal, Md Shakil Hasan

Mechanical Engineering Faculty Publications

Background

Rapid consumption of fossil fuels as well as rising environmental deterioration caused by extreme CO2 emissions has become crucial in searching for a clean and renewable energy source such as biodiesel. The current work is an attempt to produce biodiesel from a potential non-edible feedstock of Aphanamixis polystachya, locally known as ‘Royna’ seed oil in Bangladesh.

Methods

Royna oil was extracted from the seed by Soxhlet extraction method. Biodiesel was synthesized by a three-step process: saponification of oil, followed by acidification of the soap, and esterification of the free fatty acid (FFA).

Results

The result presented showed that …

28 Ghz Patch Antenna Array With Reduced Mutual Coupling For 5g Communications Systems, Rahabu F. Mwang’Amba, Hashimu Uledi Iddi

Tanzania Journal of Engineering and Technology (TJET)

A 28 GHz patch antenna array with reduced mutual coupling for 5G communication systems is presented in this paper. Two elements antenna array was simulated with a periodic boundary to represent an infinity array. The antenna array is attached with a pair of the coupled directional coupler with a coupling value of -3.47 dB, and transmission lengths of 3.40 mm and 7.62 mm depending on the antenna array's magnitude and phase coefficient were designed and simulated. A reduced mutual coupling of -31.86 dB compared to -10.75 dB for an array without a decoupling network was observed. The wide scanning angle …

Design Practice Book Of Mt-293 Parametric Computer-Aided Design, Raymond K.F. Lam, Md. Shahadat Hossain

Open Educational Resources

The design practice book is written for students who are enrolled in the MT-293 Parametric Computer-Aided Design course at CUNY Queensborough Community College. The book provides step-by-step instructions on creating two-dimensional models and three-dimensional models using SolidWorks software. The book also include laboratory assignments.

Mechanistic Understanding Of Phase Stability, Transformation, And Strengthening Mechanisms In Lightweight High Entropy Alloys And High Entropy Ceramics, Ganesh Walunj

ETD Archive

High-entropy alloys (HEAs) are a novel family of solid-solution alloys that have gained international interest due to their exceptional characteristics. Because of the need from the transportation and defense sectors, lightweight HEAs have attracted researcher’s curiosity as prospective advanced materials. Low-weight high entropy alloy synthesizes using arc melting with a mass ratio of AlCrFeMnTix(0.1,0.15,0.2). The synthesized HEA is comprised of a mixture of body center cubic (bcc) and ordered bcc (L21) solid solution phases. The synthesized HEAs have heat treated at 650C, 800C, and 1150C for 1hr, 4hr after solutionized at 1150C for 2 hr to understand the effect of …

Mechanical Actuation Via Resorbable Materials, Bethany Parkinson

Undergraduate Honors Theses

Resorbable materials—or materials which diffuse into their surroundings—present a promising means of actuating mechanical systems. In current practice, such as in the realm of in vivo surgical devices, resorbable materials are often intended to perform a temporary function and completely dissolve when that function is completed (e.g. resorbable sutures). In this paper, resorbable materials are proposed for use in a different way: as a means for actuating mechanical systems. We create several prototypes which demonstrate that resorbable materials, combined with stored energy, can be used to actuate mechanical systems under several loading conditions and in various applications. We also present …

A Primer On The Factories Of The Future, Noble Anumbe, Clint Saidy, Ramy Harik

Faculty Publications

In a dynamic and rapidly changing world, customers’ often conflicting demands have continued to evolve, outstripping the ability of the traditional factory to address modern-day production challenges. To fix these challenges, several manufacturing paradigms have been proposed. Some of these have monikers such as the smart factory, intelligent factory, digital factory, and cloud-based factory. Due to a lack of consensus on general nomenclature, the term Factory of the Future (or Future Factory) has been used in this paper as a collective euphemism for these paradigms. The Factory of the Future constitutes a creative convergence of multiple technologies, techniques, and capabilities …

Design And Performance Of A Directional Permeability Membrane, Hamidreza Bayat

Mechanical Engineering Research Theses and Dissertations

A directional permeability membrane was designed, fabricated, and tested with the goal of allowing flow in one direction and preventing flow in the opposite direction. The membranes were constructed from two porous polyimide sheets with different thicknesses and bonded with double sided tape on the perimeter to create a separation in the range of 25-75 µm. Nine holes with diameter of 0.5 and 1 mm were cut in a polyimide sheet with thickness of 125 µm and four circular holes with diameter of 0.25 mm were cut in a polyimide sheet with thickness of 25 µm. The holes were cut …

Planning Of Air Conditioner Cooling Load In The Dean Room Of The Faculty Of Engineering And Information Technology University Of Pgri Semarang, Slamet Supriyadi, Irna Farikhah, Suhartono Suhartono

Journal of Materials Exploration and Findings

The specification of the cooling load or chiller in the FTI UPGRIS dean's room currently requires a review of the distribution of cooling air in the room due to the number of electronics and occupants in the room and the size of the air conditioner. Therefore, the room must be taken into account to prevent insufficient cooling load, As a result, it is impossible to reach the desired temperature and humidity set. The FTI Dean's room has an air conditioner with a cooling capacity of 1 unit. It should be able to cover the amount of cooling in the room. …

Vibrating Flexoelectric Micro-Beams As Angular Rate Sensors, Yilin Qu, Feng Jin, Jiashi S. Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We studied flexoelectrically excited/detected bending vibrations in perpendicular directions of a micro-beam spinning about its axis. A set of one-dimensional equations was derived and used in a theoretical analysis. It is shown that the Coriolis effect associated with the spin produces an electrical output proportional to the angular rate of the spin when it is small. Thus, the beam can be used as a gyroscope for angular rate sensing. Compared to conventional piezoelectric beam gyroscopes, the flexoelectric beam proposed and analyzed has a simpler structure.

Vibrating Flexoelectric Micro-Beams As Angular Rate Sensors, Yilin Qu, Feng Jin, Jiashi S. Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We studied flexoelectrically excited/detected bending vibrations in perpendicular directions of a micro-beam spinning about its axis. A set of one-dimensional equations was derived and used in a theoretical analysis. It is shown that the Coriolis effect associated with the spin produces an electrical output proportional to the angular rate of the spin when it is small. Thus, the beam can be used as a gyroscope for angular rate sensing. Compared to conventional piezoelectric beam gyroscopes, the flexoelectric beam proposed and analyzed has a simpler structure.

Power And Voltage Modelling Of A Proton-Exchange Membrane Fuel Cell Using Artificial Neural Networks, Tabbi Wilberforce, Mohammad Biswas, Abdelnasir Omran

Mechanical Engineering Faculty Publications and Presentations

A proton exchange membrane fuel cell (PEMFC) is a more environmentally friendly alternative to deliver electric power in various applications, including in the transportation industry. As PEMFC performance characteristics are inherently nonlinear and involved, the prediction of the performance in a given application for different operating conditions is important in order to optimize the efficiency of the system. Thus, modelling using artificial neural networks (ANNs) to predict its performance can significantly improve the capabilities of handling the multi-variable nonlinear performance of the PEMFC. However, further investigation is needed to develop a dynamic model using ANNs to predict the transient behavior …

Energy Consumption Analysis Using Measured Data From A Net-Zero Energy Commercial Building In A Cold And Dry Climate, Sukjoon Oh, John F. Gardner

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Zero-energy buildings have a critical role in reducing global energy use and greenhouse gas emissions. However, few studies have analyzed net-zero energy commercial buildings using measured energy use such as whole-building level and end-use level data. This paper presents an energy consumption analysis for the first net-zero energy commercial building in Idaho, U.S., in a cold and dry climate using measured end-use data from this building as well as measured whole-building energy use. Monthly bill data analysis, end-use data analysis, and Energy Use Intensity (EUI) analysis were conducted. The combined analysis of this study shows that the HVAC system was …

Out-Of-Plane Load-Bearing And Mechanical Energy Absorption Properties Of Flexible Density-Graded Tpu Honeycombs, Ibnaj Anamika Anni, Kazi Zahir Uddin, Nicholas Pagliocca, Nand Singh, Oyindamola Rahman, George Youssef, Behrad Koohbor

Henry M. Rowan College of Engineering Departmental Research

Honeycomb structures are widely used in applications that require excellent strain energy mitigation at low structural weights. The load-bearing and energy absorption capacity of honeycomb structures strongly depend on their cell wall thickness to edge ratios. This work studies the mechanical response and strain energy absorption characteristics of hexagonal honeycomb structures with various cell wall thicknesses in response to out-of-plane loading conditions. Honeycomb structures with various nominal densities are first additively manufactured from flexible thermoplastic polyurethane (TPU). A comprehensive experimental study characterized the mechanical strength, energy absorption performance, and the strain recoverability of the structures. Density-graded structures are then fabricated …

Data-Driven Research On Engineering Design Thinking And Behaviors In Computer-Aided Systems Design: Analysis, Modeling, And Prediction, Molla Hafizur Rahman

Graduate Theses and Dissertations

Research on design thinking and design decision-making is vital for discovering and utilizing beneficial design patterns, strategies, and heuristics of human designers in solving engineering design problems. It is also essential for the development of new algorithms embedded with human intelligence and can facilitate human-computer interactions. However, modeling design thinking is challenging because it takes place in the designer’s mind, which is intricate, implicit, and tacit. For an in-depth understanding of design thinking, fine-grained design behavioral data are important because they are the critical link in studying the relationship between design thinking, design decisions, design actions, and design performance. Therefore, …

Geometric Analysis Of Insect Wing Vein Network, Jacob White, Ying Hu, Sangjin Ryu, Seunghee Kim, Haipeng Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

An insect wing consists of a thin membrane supported by a system of veins, and flow of blood through the system of veins is critical for maintaining healthy insect wings. Better understanding of the insect wing vein circulation requires to know how the efficiency of blood flow in an insect wing relates to the geometric shape of the vein. Our investigation of the wing vein network of a dragonfly Anax junius follows the idea of Murray’s law, which is established in the study of efficiency of the vein network and the geometric shape of the vein. Instead of using the …

Infrared And Fluorescent Thermal Imaging And Thermal Transport Characterization Of Engineering Devices And Systems, Swapnil Suryakant Salvi

Mechanical and Aerospace Engineering Dissertations - Archive

Infrared (IR) thermal imaging is widely used for non-contact temperature measurement in engineering. IR camera detects thermal emissions from the target surface in a certain wavelength range, which, using the known surface emissivity, can be converted to a pixel-by-pixel temperature map. Fluorescence imaging also works along similar lines. This Ph.D. dissertation contributes towards thermal imaging and thermal transport characterization in engineering devices/systems using infrared and fluorescence imaging. In the first two parts of this work, infrared thermal imaging is used for measuring thermal conductivity of thin wires and for spotting unusual activities in a three-dimensional integrated circuit (3D IC). In …

In-Situ Observation Of Extrusion Process In Thermoplastic Material Extrusion Based Additive Manufacturing, Ye Hong

Mechanical and Aerospace Engineering Dissertations - Archive

In thermoplastic material extrusion-based additive manufacturing, solid polymer filaments are fed into extruders to generate extrudates that are needed to build 3D plastic products. There is a finite gap between the inner surface of an extruder and the edge of a filament. This gap facilitates the insertion and translation of the filament inside the extruder. However, it is still not clear how the gap is filled during the extrusion. The lack of this information makes it difficult to model the temperature distribution and flow profile during the extrusion. In this work, we built experimental apparatus to directly observe the gap-filling …

Multi-Objective Aero/Mechanical Design Optimization Of Gp Turbine Blades Platform Contour Using Adjoint Solver And Impact On Secondary Losses, Mostafa Soliman

Mechanical and Aerospace Engineering Dissertations - Archive

Gas Turbines Hot Gas Path components represent the major contribution to generating power in Gas Turbines They are the components that mainly extract power from hot gasses that come out of the combustion Chamber (Combustor). Due to harsh temperature and environment, these components are vulnerable to high thermal and mechanical stresses which affect its durability, life, and efficiency. Hot Gases go through these components can reach very high max temperature. Max blade alloy metal temp in Gas Path blades can reach 1800-1900 F. Because of these severe operation conditions, a very careful prediction of stresses, thermal distribution, losses and flow …

Cold Plate Based Dynamic Liquid Cooling At Data Center And Chip Level, Pardeep Shahi

Mechanical and Aerospace Engineering Dissertations - Archive

The rising demand for high-performance central and graphical processing units has resulted in the need for more efficient thermal management techniques like direct-to-chip liquid cooling. Direct Liquid Cooling using cold plates is one of the most efficient and investigated cooling technology since the 1980s. Major data and cloud providers like IBM, Microsoft, and Google are actively deploying liquid-cooled data center infrastructure due to rising computational demands but its performance and efficiency can be further be enhanced using dynamic cooling technologies. At the chip level since the early ’60s, based on Moore’s law, transistor density has been doubling every generation resulting …

Interactions Of Vortices With Differing Creation Mechanisms In The Wake Of A Normal Flat Plate-Delta Flat Plate Couple: A Numerical Study., Cheruvateth Vivek Nair

Mechanical and Aerospace Engineering Dissertations - Archive

ABSTRACT: Fluid flow is characterized by the presence of various coherent vortical structures such as vortex tubes, vortex streets, and eddies. When these vortical structures interact with each other or other distinct mechanisms in a fluid, they form a chaotic region of mixing where a large transfer of mass and energy is observed; This phenomenon is called a vortex interaction and is commonly observed in nature across large Reynolds number regimes. In engineering, vortex interactions are an important topic of research in areas such as mixing, flow induced vibrations, propulsion, aerodynamics, convection, heat island effects, hydrodynamics, and atmospheric Sciences, to …

Fixed Wing Aircraft Collision Avoidance Using Collision Cone Theory, Andrew T. Iii Beary

Mechanical and Aerospace Engineering Theses - Archive

This thesis develops the guidance and control components of an aircraft collision avoidance system, using a collision cone-based approach. These guidance and control laws are developed by considering the nonlinear relative kinematic equations of the aircraft that are on a collision course, as well as the nonlinear flight dynamics of the aircraft performing the collision avoidance maneuver. The longitudinal and lateral-directional axes of the aircraft are considered separately. The developed guidance and control laws are subsequently integrated with the nonlinear aircraft dynamics in a MATLAB/Simulink framework, and simulations performed to demonstrate the working of the overall system.

Peridynamic Modeling Of Crack Propagation In Brittle Materials With Electromechanical Coupling, Semsi Coskun

Dissertations

The bond-based peridynamics (BB-PD) is a widely used peridynamic model in the literature. Despite Poisson's ratio restriction, it still serves as a powerful tool to solve challenging engineering problems with a relatively cheap computational cost. Consider the Poisson ratio of the material does not deviate from the ones that BB-PD can model. In that case, it becomes advantageous to use the BB-PD compared to other PD models in terms of computational cost and simplicity. However, the BB-PD suffers from the so-called surface or skin effect where the material response at boundaries becomes softer than the bulk material points. As a …

Reactive Motion Planning Of Autonomous Vehicles In 3-Dimensional Environments Using Collision And Rendezvous Cones, Kashish Dhal

Mechanical and Aerospace Engineering Dissertations - Archive

This dissertation presents a collision cone/rendezvous cone-based approach for reactive motion planning in three-dimensional dynamic environments. Collision avoidance is fundamental to robot motion planning. In dynamic environments, the path and velocities of obstacles are not known a-priori, and hence it is a common practice to use reactive planners. Reactive planners should be computationally inexpensive because they need to act fast to avoid potential collisions. To reduce the computational load, a majority of motion planning algorithms model the shapes of the robots and obstacles as a circle/sphere. However, when the objects are elongated more in one direction than another, the spherical …

Effects Of Imu Sensor Location And Number On The Validity Of Vertical Acceleration Time-Series Data In Countermovement Jumping, Dianne Althouse

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Many devices are available for measuring the height of a CMJ. An inertial measurement unit (IMU) measures linear acceleration, orientation, and angular velocity. As an alternative to using IMU estimates of flight time, CMJ height could be estimated by integrating the IMU time-series signal for vertical acceleration to derive CMJ take-off velocity in order to track whole-body center of mass (WBCoM) movement, yet this approach would require valid IMU acceleration data. Thus, the purpose of this study was to quantify the effects of IMU sensor location and number on the validity of vertical acceleration estimation in CMJ. Thirty young adults …

Speed Of Small Droplets On Repellent Surfaces, Addison J. Litton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A droplet of fluid can slide or roll down an angled surface if the droplet doesn’t stick to the plate (e.g., droplets on glass). The most common surface to allow for such this motion are hydrophobic surfaces. One example is a freshly waxed car where the rain beads up and rolls off. Another example is if a pan is heated to a high enough temperature then when small amounts of water are added the droplet will skitter around on the surface for a moment before boiling away. This high temperature effect where droplets rest on a vapor layer underneath cause …

Impact Of Spray Coating On The Performance Of Hydrophobic Membranes, Dominick J. Maiorano, Hamid Fattahijuybari, David Warsinger

Discovery Undergraduate Interdisciplinary Research Internship

Membrane distillation (MD) is a rapidly emerging water treatment technology used to combat the global water crisis. Membrane pore wetting is a primary barrier to widespread industrial use of MD. The primary causes of membrane wetting are membrane fouling and an exceedance of liquid entry pressure. The development of different types of polymer membranes and the use of pretreatment have led to significant movement towards the prevention of wetting in MD. We sought to take a new approach to combat membrane wetting that involves coating these membranes with hydrophilic chemical compounds, which consequently would decrease their air permeability. Pulling data …

Thin Film Evaporation Through Engineered Copper Micropillar Arrays, Alejandro Amador

Open Access Theses & Dissertations

This work explored and characterized the evaporator section of a fully engineered heat pipe, a proposed semi-passive cooling solution for the thermal management at high heat fluxes, with the use of thin film evaporation. High heat loads present a problem in electronics, circuitry, space, and defense applications which are the main target areas for this cooling solution. Conventionally manufactured flat samples made of copper micropillar arrays were tested to determine their heat removal capabilities for high heat flux applications. The samples were manufactured with 400 μm micropillar hydraulic diameter, various micropillar spacings ranging from 500-1100 μm, with 500 μm and …