Mechanical Engineering Commons^™

Task Complexity, And Operators’ Capabilities As Predictor Of Human Error: Modeling Framework And An Example Of Application, Maria Chiara Leva, Alberto Caimo, Rebecca Duane, Micaela Demichela, Lorenzo Comberti

Conference Papers

This paper presents the initial framework adopted to assess human error in assembly tasks at a large manufacturing company in Ireland. The model to characterize and predict human error presented in this paper is linked conceptually to the model introduced by Rasch (1980), where the probability of a specified outcome is modelled as a logistic function of the difference between the person capacity and item difficulty. The model needs to be modified to take into account an outcome that is not dichotomous and feed into the interaction between two macro factors: (a) Task complexity: that sum-marises all factors contributing to …

Fabrication And Characterization Of Advanced Materials Using Laser Metal Deposition From Elemental Powder Mixture, Xueyang Chen

Doctoral Dissertations

"Over the past decades of years, a great deal of money has been spent to machine large and complex parts from high-performance metals (i.e., titanium components for aerospace applications), so users attempt to circumvent the high cost of materials. Laser metal deposition (LMD) is an additive manufacturing technique capable of fabricating complicated structures with superior properties. This dissertation aims to improve the applications of LMD technique for manufacturing metallic components by using various elemental powder mixture according to the following three categories of research topics. The first research topic is to investigate and develop a cost-effective possibility by using elemental …

Laser Foil Printing And Surface Polishing Processes, Chen Chen

Doctoral Dissertations

"A foil-based additive manufacturing technology for fabricating metal parts, called Laser Foil Printing (LFP), was proposed and developed in this dissertation. The manufacturing sub-processes comprising the LFP technology were comprehensively studied, which include the laser spot welding of foil, laser raster-scan welding of foil, laser cutting of foil, and laser polishing processes. The fabricated free-form parts were demonstrated and own better mechanical properties (micro hardness and tensile strength) than the raw material, because of the rapid-cooling process of laser welding. The full and strong bond between layers was formed by the laser welding process, with no micro-cracks or pores observed. …

Investigation Of Microstructure And Mechanical Properties By Direct Metal Deposition, Jingwei Zhang

Doctoral Dissertations

"Microstructure and properties of Direct Metal Deposition (DMD) parts are very crucial to meeting industrial requirements of parts quality. Prediction, and control of microstructure and mechanical properties have attracted much attention during conventional metal manufacturing process under different conditions. However, there is few investigations focused on microstructure simulation and mechanical properties control under different process parameters during DMD process. This dissertation is intended to develop a multiscale model to investigate Ti6Al4V grain structure development and explore Ti6Al4V based functionally graded material (FGM) deposit properties during DMD process. The first research topic is to investigate and develop a cellular automaton-finite element …

Monitoring Of Hybrid Manufacturing Using Acoustic Emission Sensor, Haythem Gaja

Doctoral Dissertations

"The approach of hybrid manufacturing addressed in this research uses two manufacturing processes, one process builds a metal part using laser metal deposition, and the other process finishes the part using a milling machining. The ability to produce complete functioning parts in a short time with minimal cost and energy consumption has made hybrid manufacturing popular in many industries for parts repair and rapid prototyping. Monitoring of hybrid manufacturing processes has become popular because it increases the quality and accuracy of the parts produced and reduces both costs and production time. The goal of this work is to monitor the …

Modeling And Experimental Investigations On Particle Dynamic Behaviors In Laser 3d Printing With Blown Powder, Wei Li

Doctoral Dissertations

"Pre-mixed powder is frequently-used powder supply to fabricate Functional Gradient Material (FGM) by Laser 3D printing, which is also called Laser Metal Deposition (LMD). The deposited FGM composition is expected to be similar or same as supplied powder mixture. However, because pre-mixed powder has different particle densities and particle sizes, the caused particle acceleration differences can result in the separation in powder mixture. Up to now, there was no study focused on pre-mixed powders' flow behavior in LMD. The current research aims to investigate the flow behaviors of pre-mixed powder supplied for LMD through both experimental and modeling approaches. In …

Modeling And Characterization Of Thermo-Oxidative Behavior Of Bismaleimide Composites, Rafid Muhammad Hussein

Doctoral Dissertations

"High-temperature polymer matrix composites (HTPMCs) are susceptible to thermo-oxidation, which accelerates the composites' degradation and reduces the service life. Mechanical properties of HTPMCs deteriorate due to coupled thermo-oxidation and cross-linking mechanisms. Bismaleimides (BMIs) are commonly used high-temperature resins for aerospace applications. This work presents the viability of using experimental weight loss to model the spatial distribution of oxidation when the oxidized polymer matrix is not discernible. Three tasks are introduced: (1) Anisotropic oxidation prediction using optimized weight loss behavior of bismaleimide composites, (2) A multi-scale modeling of thermo-oxidative effects on the flexural behavior of cross-ply bismaleimide composites, and (3) Thermo-oxidative …

Modeling And Simulation Of Viscoplasticity, Recrystallization, And Softening Of Alloyed Steel During Hot Rolling Process, Xin Wang

Doctoral Dissertations

"Hot rolling is one of the most important and complex deformation processes in steel manufacturing and is essential to final product quality. The objective of this study is to investigate viscoplasticity, dynamic recrystallization, and static softening of alloyed metal during hot rolling process. Gleeble hot compression tests were performed to provide experimental stress-strain curves at different temperatures and strain rates. An inverse finite element analysis was performed to calibrate the experimental curves. Viscoplastic models including a Johnson-Cook (JC) model, a Zerilli-Armstrong (ZA) model, and a combined JC and ZA model were developed. Dynamic recrystallization behavior was investigated and modeled based …

Soy-Based Polyurethane Foam For Insulation And Structural Applications, Gurjot S. Dhaliwal

Doctoral Dissertations

"Polyurethane (PU) foams are widely used as insulation materials due to their high insulation properties and low cost compared to conventional materials such as styrene and mineral wool. PU foams are traditionally fabricated with petroleum-based precursors. However, high crude price and higher carbon footprint has lead interest of researchers to synthesis PU foams using plant-based raw materials, that are inexpensive and renewable. In this dissertation, PU foams were fabricated using soy-based polyol and its thermal and mechanical properties were investigated. In the first part, of PU foam samples with different formulations were fabricated using soy-based polyol HB230, and varying amounts …

Direct Printing Of Single-Crystal Silicon By Microscale Nanoparticle Printing And Confined Laser Melting And Crystallization, Wan Shou

Doctoral Dissertations

"The transport and interfacial phenomena in laser melting and crystallization of silicon in micro-/nano-scale confinement lacks sufficient understanding. Uncovering the underlying mechanisms, and hence harness the melting and crystallization processes can help the formation of controllable single-crystal structures or patterns. In this dissertation, a molecular dynamics (MD) simulation was conducted to calculate the interfacial free energy of the silicon system in contact with flat and structured walls. Then the calculated interfacial energies were employed to predict the nucleation mechanisms in a slab of liquid silicon confined by two walls and compared with MD simulation results. Further, in combination with a …

Modeling And Control Of Probe-On-Probe Dynamics In Dual-Probe Atomic Force Microscopy, Ayad Al-Ogaidi

Doctoral Dissertations

“The atomic force microscope (AFM) is a widely used instrument for imaging and direct manipulation of materials and particles at the nanoscale. The AFM uses a probe, which is a microcantilever with a sharp point at the end. Typically, the AFM is constructed with a single probe. The disadvantage of this construction is that it can only be used either for imaging or manipulation in one implementation. An AFM was constructed using two probes, permitting simultaneous imaging and manipulation. A dual-probe AFM (DP-AFM) provides a foundation for feedback controlled manipulation.

Paper I investigates probe-on-probe contact stability and examines the dynamics …

Design For Optical Metamaterial Design For Optical Metamaterial Absorber, Huixu Deng

Doctoral Dissertations

“Optical metamaterlal (MM) absorbers in the visible or near-infrared range have been widely investigated in these years since they are crucial in many promising applications, such as solar energy harvesting systems, thermo-photovoltaic energy conversion devices, thermal imaging and emissivity control. This dissertation aims to design and investigate various optical metamaterial absorbers based on different mechanisms and theories, such as cavity resonance, impedance match, equivalent circuit model and waveguide stop light mode. First, via utilizing the cavity resonance, a tunable narrowband MM absorber/emitter for thermophotovoltaic (TPV) is designed and analyzed based on gold nanowire cavities to improve the overall efficiency of …

Quantitative Phase-Field Modeling Of Crack Propagation In Multi-Phase Materials, Arezoo Emdadi

Doctoral Dissertations

”Research presented in this dissertation is focused on developing and validating a computational framework for study of crack propagation in polycrystalline composite ceramics capable of designing micro-architectures of phases to improve fracture toughness and damage tolerance of ZrB₂-based ultra-high temperature ceramics (UHTCs). A quantitative phase-field model based on the regularized formulation of Griffith’s theory is presented for crack propagation in homogenous and heterogeneous brittle materials. This model utilizes correction parameters in the total free energy functional and mechanical equilibrium equation within the crack diffusive area to ensure that the maximum stress in front of the crack tip is …

Enhancement Of Performance Of Micro Direct Ethanol Fuel Cells By Structural Modification, Sindhuja Valluri

Masters Theses

“Direct Ethanol Fuel Cells (DEFC’s) are becoming more important in current energy conversion devices because of their higher efficiency compared to other fuel cells. However, the performance of current DEFC’s is not efficient in providing energy to meet increasing energy demand. The objective of this work is to make the cell compact and at the same time improve performance. For this purpose, we have removed gasket and endplates to make structure compact and increased surface area by developing a new corrugated structure. This work also uses 3D printing technology Fused Deposition Modeling (FDM) to make pocket backing case to improve …

Controlling Phase Fractions Of 304l-Ss In Selective Laser Melting Using Cooling Rate, Eberechukwu Anthony Okoro

Masters Theses

"This study examines the thermal profile and the ferrite-austenite phase fractions upon heating and cooling of 304- stainless steel powder via Selective Laser Melting (SLM). Experiments were performed to validate the ABAQUS finite element model, while the phase transformation simulation was performed using MatCalc and ThermoCalc. A correlation between the thermo-mechanical changes in ABAQUS and the microstructural changes from MatCalc was obtained by matching their cooling rates. The result indicates that cooling rate has a significant effect on the phase fractions of FCC and BCC formed in 304L stainless steel via the SLM process. The results also indicate that for …

Investigation Of The Information Provided By Light Touch For Balance Improvement In Humans, Anirudh Saini

Masters Theses

"This study investigates the information provided by Light Touch (LT) in improving human postural stability without mechanical assistance. Light Touch, an interaction force with a magnitude about 1 N, is known to improve postural stability in humans during quiet standing. However, the nature of the information from LT that helped improve balance is yet unknown. In this work, we hypothesized that LT provides information about one's body kinematics. We used a haptic robot to provide modulated, measurable light interaction force on the high back haptic location of humans to provide body kinematics-dependent information through LT. Standing balance experiments were performed …

Computational Investigation Of Polymer Electrolyte Membrane Fuel Cell With Nature-Inspired Fibonacci Spiral Flow Field, Suleyman Kose

Masters Theses

"Polymer electrolyte membrane fuel cells (PEMFC) are promising clean energy devices. The flow field design has crucial role in PEMFC performance for effective distribution of reactants and removal of products. Several nature-inspired flow field designs have recently been proposed in the literature. Common characteristics of these designs were sudden changes in the flow direction through sharp bends and flow field geometries restrained to areas having corners. In this thesis, Fibonacci spiral configuration, which is found in the nature from hurricanes to seashells, was considered for flow field pattern of a PEMFC. Contrary to the bio-inspired designs proposed in previous studies, …

Designed Extrudate For Ceramic Additive Manufacturing, Devin Mcmillen

Masters Theses

"The objective of this thesis work was to design ceramic paste systems that assist in achieving a high theoretical density ( > 95%) after deposition by a novel additive manufacturing process, i.e. Ceramic On-Demand Extrusion (CODE). The work is encompassed in five main sections: Sections 1 and 2 provide an introduction and literature review of relevant topics for the following sections of experimentation. Section 3 provides an analysis of a reaction chemistry to identify three discrete materials that could be combined via CODE and result in zirconium diboride (ZrB₂) post-sintering. Section 4 describes the development of a high solids …

Impact Of Vapor Polishing On Surface Quality And Mechanical Properties Of Extruded Abs, Clayton Neff, Matthew Trapuzzano, Nathan B. Crane

Faculty Publications

Purpose — Additive manufacturing (AM) is readily capable of producing models and prototypes of complex geometry and is advancing in creating functional parts. However, AM processes typically underperform traditional manufacturing methods in mechanical properties, surface roughness, and hermeticity. Solvent vapor treatments (vapor polishing) are commonly used to improve surface quality in thermoplastic parts, but the results are poorly characterized.

Design/methodology/approach — This work quantifies the surface roughness change and also evaluates the effect on hermeticity and mechanical property impacts for “as-printed” and acetone vapor-polished ABS tensile specimens of 1, 2, and 4 mm thicknesses produced by material extrusion (FDM).

Findings …

Controlling Normal Stiffness In Droplet-Based Linear Bearings, Qi Ni, Nathan B. Crane

Faculty Publications

While Capillary forces are negligible relative to gravity at the macroscale, they provide adequate force to effectively manipulate millimeter to micro meter objects. The fluidic actuation can be accomplished using droplets that also act as bearings. While rotary droplet bearings have been previously demonstrated, this paper considers the performance potential of discrete droplets acting as linear bearings. Specifically, it addresses the positioning accuracy of a droplet-based bearing consisting of a droplet between a moving plate and a stationary substrate with constrained wetting region under a normal load using both closed form analytical solutions and numerical simulations. The vertical force and …

Development Of Antimicrobial Chitosan Based Nanofiber Dressings For Wound Healing Applications, Lee Cremar, Jorge Gutierrez, Jennifer Martinez, Luis A. Materon, Robert Gilkerson, Fenghua Xu, Karen Lozano

Mechanical Engineering Faculty Publications

Objective(s): Chitosan based composite fine fibers were successfully produced via a centrifugal spinning technology. This study evaluates the ability of the composites to function as scaffolds for cell growth while maintaining an antibacterial activity.

Materials and Methods: Two sets of chitosan fiber composites were prepared, one filled with anti-microbial silver nanoparticles and another one with cinnamaldeyhde. Chitosan powder was dissolved in trifluoroacetic acid and dichloromethane followed by addition of the fillers. The fiber output was optimized by configuring the polymer weight concentration (7, 8, and 9 w/w% chitosan) and applied angular velocity (6000-9000 RPM) within the spinning process.

Results: …

A Review Of Latest Developments, Progress, And Applications Of Heat Pipe Solar Collectors, Abdellah Sharifian, Mehdi Khiadani, Ataollah Nosrati

Research outputs 2014 to 2021

Among all the available solutions to the current high energy demand and consequent economic and environmental problems, solar energy, without any doubt, is one of the most promising and widespread solutions. However, conventional solar systems face some intractable challenges affecting their technical performance and economic feasibility. To overcome these challenges, increasing attention has been drawn towards the utilization of heat pipes, as an efficient heat transfer technology, in conventional solar systems. To the authors’ knowledge, despite many valuable studies on heat pipe solar collectors (mainly during the last decade), a comprehensive review which surveys and summarizes those studies and identifies …

Kinematic/Static Model Of Complex Compliant Mechanisms With Serial-Parallel Substructures: A General Approach, Larry L. Howell, Mingxiang Ling, Junyi Cao

Faculty Publications

Kinematic and static analyses of compliant mechanisms are crucial at the early stage of design, and it can be difficult and laborsome for complex configurations with distributed compliance. In this paper, a general and concise kinematic/static modeling method of flexure-hinge-based compliant mechanisms with arbitrary serial-parallel substructures is presented to provide accurate and efficient solutions by combining the matrix displacement method with the transfer matrix method. The transition between the elemental stiffness matrix and the transfer matrix of the flexure hinge and the flexible beam is straightforward, enabling the condensation of a hybrid serial-parallel substructure into one equivalent element simple. Then, …

Ambiqual – A Full Reference Objective Quality Metric For Ambisonic Spatial Audio, Miroslaw Narbutt, Andrew Allen, Jan Skoglund, Michael Chinen, Andrew Hines

Conference papers

Streaming spatial audio over networks requires efficient encoding techniques that compress the raw audio content without compromising quality of experience. Streaming service providers such as YouTube need a perceptually relevant objective audio quality metric to monitor users’ perceived quality and spatial localization accuracy. In this paper we introduce a full reference objective spatial audio quality metric, AMBIQUAL, which assesses both Listening Quality and Localization Accuracy. In our solution both metrics are derived directly from the B-format Ambisonic audio. The metric extends and adapts the algorithm used in ViSQOLAudio, a full reference objective metric designed for assessing speech and audio quality. …

Electric Solid Propellant Ablation In A Pulsed Electric Thruster, Matthew S. Glascock, Joshua L. Rovey

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Electric solid propellants are advanced solid chemical rocket propellant that can be controlled (ignited, throttled and extinguished) with electric current. Work reported here focuses on application of electric solid propellant in a pulsed electric thruster similar to a pulsed plasma thruster. In the future it may be possible to develop a dual-mode electric solid propellant thruster that is switchable between steady applied electric current chemical mode and pulsed alternating electric current electric mode. Results presented here use a laboratory test thruster to create an arc discharge of 5-20 J per pulse in a cylindrical cavity of propellant. Results for Teflon …

Electrospray Mass Spectroscopy Of A Han-Based Monopropellant, Mitchell J. Wainwright, Joshua L. Rovey, Shawn W. Miller, Benjamin D. Prince, Steven P. Berg

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A mixture of [Emim][EtSO4]-HAN is a potential propellant suitable in a multi-mode chemical-electric microtube-electrospray micro propulsion system. This paper reports experimental mass spectrum results for this liquid when electro sprayed in a 50 μm capillary emitter. Mass spectra from 0-600 amu were obtained over a variety of angles and flow rates from 2 pL/sec to 3 nL/sec in both cation and anion extraction mode. Effects of flow rate and angular orientation on the spectra agree well with literature. Results show at least three of the four monomer species are emitted, along with numerous other species, some of which have been …

Set-Theoretic Model Reference Adaptive Control Of A Generic Transport Model, Ehsan Arabi, Tansel Yucelen, Nhan T. Nguyen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper illustrates an application of a recently developed set-theoretic model reference adaptive control architecture on a generic transport model developed by NASA. The set- theoretic model reference adaptive control allows the system error bound between the state of an uncertain dynamical system and the state of a given reference model to be less than a-priori, user-defined worst-case performance bound. Thus, it has the capability to enforce strict performance guarantees to the adaptively controlled uncertain dynamical systems. specifically, after designing set-theoretic adaptive controllers for both longitudinal and lateral-directional dynamics here, the efficacy of this architecture is illustrated on the NASA …

Surfactants, Thermal And Surface Energy Effects On Emulsions’ Transport Properties: A Study Using Lattice Boltzmann Method, Wessam Falih Hasan

Wayne State University Dissertations

This work aims to provide an efficient Gunstensen LBM based CFD model, capable of solving complex problems related to droplets behavior in shear and parabolic flows.

Thermal conditions determine the outcome of the physical and transport properties of emulsions during their various processing phases. A better understanding of the intricate relationship between thermal, surfactants and hydrodynamics can help in the optimization of these processes during the production of emulsions. To investigate the outcome of coupling thermal, surfactants and hydrodynamics on emulsions behavior, a robust quasi-steady thermal-surfactants numerical scheme is presented and used here. To validate the model, the rheological behavior …

Application Of Improved Fast Dynamic Allan Variance For The Characterization Of Mems Gyroscope On Uav, Qian Zhang, Xueyun Wang, Shiqian Wang, Chaoying Pei

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Microelectromechanical systems (MEMS) are core components in unmanned aerial vehicles (UAV). The precision of MEMS sensors is very important when the GPS signal is invalid. However, the precision and performance of MEMS sensors will be degraded by the changing of environment. Therefore, estimation and identification of the various noise terms existing in MEMS sensors are deemed to be necessary. The Allan variance is a common and standard method to analyze MEMS sensors, but it cannot be used to analyze the dynamic characteristics. The dynamic Allan variance (DAVAR) is a sliding version of the Allan variance. It is a practical tool …

A Two-Dimensional Simulation Of Grain Structure Growth Within Substrate And Fusion Zone During Direct Metal Deposition, Jingwei Zhang, Lei Yan, Wei Li, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this chapter, a predictive multiscale model based on a cellular automaton (CA)-finite element (FE) method has been developed to simulate thermal history and microstructure evolution during metal solidification for direct metal deposition (DMD) process. The macroscopic FE calculation that is validated by the thermocouple experiment is developed to simulate the transient temperature field and cooling rate of single layer and multiple layers. In order to integrate the different scales, a CA-FE coupled model is developed to combine with thermal history and simulate grain growth. In the mesoscopic CA model, heterogeneous nucleation sites, grain growth orientation and rate, epitaxial growth, …