Engineering Commons^™

The Essential Work Of Fracture In Peridynamics, Christer Stenström, Kjell Eriksson, Florin Bobaru, Stefan Golling, Pär Jonsén

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, the essential work of fracture (EWF) method is introduced for a peridynamic (PD) material model to characterize fracture toughness of ductile materials. First, an analytical derivation for the path-independence of the PD J -integral is provided. Thereafter, the classical J -integral and PD J-integral are computed on a number of analytical crack problems, for subsequent investigation on how it performs under large scale yielding of thin sheets. To represent a highly nonlinear elastic behavior, a new adaptive bond stiffness calibration and a modified bonddamage model with gradual softening are proposed. The model is employed for two …

Mesoporous Particle Embedded Nanofibrous Scaffolds Sustain Biological Factors For Tendon Tissue Engineering, Chiara Rinoldi, Ewa KijeńSka-GawrońSka, Marcin Heljak, Jakub Jaroszewicz, Artur KamińSki, Ali Khademhosseini, Ali Tamayol, Wojciech Swieszkowski

Department of Mechanical and Materials Engineering: Faculty Publications

In recent years, fiber-based systems have been explored in the frame of tissue engineering due to their robustness in recapitulating the architecture and mechanical properties of native tissues. Such scaffolds offer anisotropic architecture capable of reproducing the native collagen fibers’ orientation and distribution. Moreover, fibrous constructs might provide a biomimetic environment for cell encapsulation and proliferation as well as influence their orientation and distribution. In this work, we combine two fiber fabrication techniques, such as electrospinning and wet-spinning, in order to obtain novel cell-laden 3D fibrous layered scaffolds which can simultaneously provide: (i) mechanical support; (ii) suitable microenvironment for 3D …

Nitric Oxide: Physiological Functions, Delivery, And Biomedical Applications, Syed Muntazir Andrabi, Navatha Shree Sharma, Anik Karan, S. M. Shatil Shahriar, Brent Cordon, Bing Ma, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical …

Design And Development Of Ultrabroadband, High-Gain, And High-Isolation Thz Mimo Antenna With A Complementary Split-Ring Resonator Metamaterial, Ammar Armghan, Khaled Aliqab, Meshari Alsharari, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel

Department of Mechanical and Materials Engineering: Faculty Publications

The need for high-speed communication has created a way to design THz antennas that operate at high frequencies, speeds, and data rates. In this manuscript, a THz MIMO antenna is designed using a metamaterial. The two-port antenna design proposed uses a complementary splitring resonator patch. The design results are also compared with a simple patch antenna to show the improvement. The design shows a better isolation of 50 dB. A broadband width of 8.3 THz is achieved using this complementary split-ring resonator design. The percentage bandwidth is 90%, showing an ultrabroadband response. The highest gain of 10.34 dB is achieved …

Restoration Of Normal Blood Flow In Atherosclerotic Arteries Promotes Plaque Stabilization, Morgan A. Schake, Ian Mccue, Evan T. Curtis, Thomas J. Ripperda Jr., Samuel Harvey, Bryan T. Hackfort, Anna Fitzwater, Yiannis S. Chatzizisis, Forrest Kievit, Ryan M. Pedrigi

Department of Mechanical and Materials Engineering: Faculty Publications

Blood flow is a key regulator of atherosclerosis. Disturbed blood flow promotes atherosclerotic plaque development, whereas normal blood flow protects against plaque development. We hypothesized that normal blood flow is also therapeutic, if it were able to be restored within atherosclerotic arteries. Apolipoprotein E-deficient (ApoE^-/-) mice were initially instrumented with a blood flow-modifying cuff to induce plaque development and then five weeks later the cuffwas removed to allowrestoration of normal blood flow. Plaques in decuffed mice exhibited compositional changes that indicated increased stability compared to plaques in mice with the cuff maintained. The therapeutic benefit of decuffingwas comparable …

The Center For Centering Dome, Olek Piechaczek, Ryan M. Scharf

Architectural Engineering

The Center for Centering seeks to create a large-scale healing center, conducive to individual centering of the mind and body. This mobile installation provides a relaxing, enclosed space while still maintaining a connection to the outdoors. The clients liked the idea of having a pop-up installation that could be easily set up as a touring display. With a deadline for installation looming in June 2022, a team of students had five months to design and manufacture the structure.

In winter 2022, the students developed custom geometry to minimize the number of individual parts and built a ¼ scale model of …

Exploring The Intersection Of Biology And Design For Product Innovations, Ajay P. Malshe, Salil Bapat, Kamlakar Rajurkar, Ang Ang, Jean-Marc Linares

Department of Mechanical and Materials Engineering: Faculty Publications

Design, development, productization, and applications of advanced product concepts are pressing for higher multifunctionality, resilience, and maximization of available resources equitably to meet the growing and continuing demands of global customers. These demands have further accelerated during the recent COVID- 19 pandemic and are continuing to be a challenge. Engineering designs are one of the most effective ways to endow products with functions, resilience, and sustainability. Biology, through millions of years of evolution, has met these acute requirements under severe resource and environmental constraints. As the manufacturing of products is reaching the fundamental limits of raw materials, labor, and resource …

Self-Assembly Of Exfoliated Graphene Flakes As Anticorrosive Coatings For Additive Manufactured Steels, Kaleb Hood, Wen Qian, Yi Xia, Savannah Krupa, Annie Dao, Sarah Ahmed, Samuel Olson, Nam Nguyen, Joseph A. Turner, Jun Jiao

Department of Mechanical and Materials Engineering: Faculty Publications

This study demonstrates the feasibility of using liquid exfoliation of expandable graphite into multilayer exfoliated graphene flakes (EGFs) to form a self-assembled thin film on an air–water interface. The film can coat the surface of additive manufactured (AM) steel substrates to enhance surface properties, specifically AM 316 stainless-steel (AM316), AM 8620 steel (AM8620), and samples of the same alloys made by conventional manufacturing (CM) processes. Liquid exfoliation offers a high yield route for an EGF coating that can cover up to 95% of the sample surface with a single application. The thin, flexible EGFs can coat a rough AM metal …

Machinability Of High Mn Steel Using Tool Life Criteria, Dika Handayani, Victor F. Okhuysen, Nicole Wagner

Engineering Faculty Articles and Research

High Mn steel alloys have shown to provide both high strength and ductility. However, current literature offers limited guidance on the machinability of these steel alloys. Therefore, this work provides turning recommendations for high Mn steel that is based on tool life data. Several indexable carbide inserts with various rake angles were used to machine cast billets of high Mn steel. Turning characteristics from various feed rates, cutting speeds, and depths of cut were analyzed. Through a design of experiments, it was determined that the feed rate was the most significant factor affecting tool life and that a tool with …

Exploring Methods For Recycling Filament Waste In 3d Printing, Max Rios Carballo

Publications and Research

The goal of the current study is to investigate cutting-edge techniques for recycling filament waste from 3D printing procedures. Appropriate waste management techniques are required to reduce this trash's harmful environmental consequences. The goal of the project is to look at new methods for recycling filament waste in order to minimize disposal and encourage reuse. To acquire data from pertinent papers and research, a thorough literature review methodology was used. The findings show that this issue may be resolved utilizing a variety of recycling techniques, including shredding, melting, and re-extrusion. The type of filament waste and the intended goal will …

Enhancing Compatibility And Mechanical Properties Of Natural Rubber Composites, Krisma Yessi Sianturi, Adam Febriyanto Nugraha, Belle Kristaura, Mochamad Chalid

Journal of Materials Exploration and Findings (JMEF)

Pure natural rubber (NR) exhibits low mechanical properties, necessitating the incorporation of additives like vulcanizing agents and fillers. Carbon black and silica, conventional fillers, are relatively expensive and not environmentally friendly. This study explores using Oil Palm Empty Fruit Bunch (OPEFB) fiber as an affordable, abundant, and biodegradable alternative filler for NR. However, compatibility issues arise between the nonpolar NR and the polar OPEFB fiber. A latex-starch hybrid coupling agent (CA (NR-St)) was added to the composite formulation to address this. NR, OPEFB fiber, and the coupling agent were mixed using an open roll mill with a 10 phr OPEFB …

Thermal Behavior Of Plain And Fiber-Reinforced Rigid Concrete Airfield Runways, Arash Karimi Pour

Open Access Theses & Dissertations

The environmental condition and temperature gradient are important factors resulting in concrete airfield runways cracking during the time. Rigid concrete airfield runways experience different thermal gradients during the day and night due to changes in air temperature. Curling and thermal expansion stresses are the main consequences resulting in various types of cracking over the surface and thickness of concrete airfield runways and increasing maintenance costs. The curvature of concrete slabs increases with an increase in the temperature gradient which is amplified when runways open to traffic. Additionally, the combination of the curling and shrinkage stresses, in rare circumstances, can be …

Characterization Of Novel Self-Healing Polymer Blends For Additive Manufacturing, Truman James Word

Open Access Theses & Dissertations

This dissertation begins with an overview of novel polymer systems which have been developed by the Polymer Extrusion Lab at the University of Texas at El Paso. Many composite polymer systems have been created using many different polymers as well as ceramics and metals primarily in the form of powders added to the bulk polymer. The bulk of this work entails a study that was conducted to develop and characterize the mechanical, shape memory and self-healing properties of three polymer blends: polylactic acid (PLA) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), acrylonitrile butadiene styrene (ABS) combined with maleated styrene-ethylene-butylene-styrene (SEBS-g-MA), and polylactic …

The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels

Electronic Theses and Dissertations

The purpose of this study was to investigate and compare the corrosion mechanisms between wrought and additive-manufactured (3D-printed) copper and stainless steel. The experimental procedure consisted of measuring the open circuit potential, electrochemical impedance spectroscopy, linear sweep voltammetry, Tafel analysis, surface topology, and scanning electron microscopy for each metal within salt water, tap water, sulfuric acid, and synthetic body fluid (excluding copper in synthetic body fluid).

Overall, printed stainless steel was more corrosion-resistant than wrought stainless steel in tap water and synthetic body fluid based on OCP, LSV, and surface topology results. Additionally, printed copper was more corrosion-resistant than wrought …

Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm

All Dissertations

Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).

While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …

The Effects Of Laser Shock Peening On The Fatigue Life Of Additive Manufactured Alsi10mg, Jacob L. Biddlecom

All Dissertations

Additive manufacturing (AM) is becoming a manufacturing process that is well established, even with all the resources and attention that has been brought to it, the field is still lacking some key understandings. Currently, there are certain aspects that are difficult to overcome. Some of the intrinsic obstacles include process-induced defects, such as porosity from lack of fusion and gaseous bubble entrapment, as well as complex thermal gradients. These defects can lead to altered material response especially when looking at the fatigue life. The fatigue behaviors of AM components can change from print to print as well as when compared …

Development Of A Fish Robot Equipped With Novel 3d-Printed Soft Bending Actuators, Steven Steele, Jorge Diaz Rodriguez, Sharun Sripathy, Turaj Ashuri, Saleh Gharaie, Yusun Chang, Amir Ali Amiri Moghadam

Symposium of Student Scholars

This paper reports on design and fabrication of a novel soft fish robot. Application of soft actuators for the fish tail will generates continuum bending motion which resembles the natural motion of the fish. However, most soft actuator mechanisms are complex and have low efficiency. Thus, to address this issue we have developed a 3D printed soft bending actuator which can be actuated with an electromotor. The basic design idea of the soft bending actuator is explained, and iteration of the design showed to create the desired motion for the soft tail. The soft actuator has been successfully integrated with …

Editorial: Disease Biomarker Analysis Based On Optical Biosensing, Tianshu Chen, Fanben Meng, Binwu Ying, Xiaoli Zhu

Department of Mechanical and Materials Engineering: Faculty Publications

Disease biomarker analysis has become a crucial tool for diagnosing and evaluating disease prognosis, especially with the increasing understanding of diseases at the molecular level. Abnormalities in various biomarkers can indicate diseased states, and can be used to rapidly and specifically detect and quantify diseases using optical biosensing techniques (Gao et al., 2023). Optical biosensing techniques have several advantages over traditional methods including higher sensitivity, specificity, and faster analysis times (Plikusiene and Ramanaviciene, 2023). It also allows for non-invasive sample collection. With advancements in optical biosensing technology, many medical conditions including cancers, infectious diseases, and autoimmune disorders can be accurately …

Editorial: Disease Biomarker Analysis Based On Optical Biosensing, Tianshu Chen, Fanben Meng, Binwu Ying, Xiaoli Zhu

Department of Mechanical and Materials Engineering: Faculty Publications

Disease biomarker analysis has become a crucial tool for diagnosing and evaluating disease prognosis, especially with the increasing understanding of diseases at the molecular level. Abnormalities in various biomarkers can indicate diseased states, and can be used to rapidly and specifically detect and quantify diseases using optical biosensing techniques (Gao et al., 2023). Optical biosensing techniques have several advantages over traditional methods including higher sensitivity, specificity, and faster analysis times (Plikusiene and Ramanaviciene, 2023). It also allows for non-invasive sample collection. With advancements in optical biosensing technology, many medical conditions including cancers, infectious diseases, and autoimmune disorders can be accurately …

Microstructure-Informed Modeling Of Hydrogen Diffusion In Zirconium Polycrystals, Alireza Tondro

Electronic Thesis and Dissertation Repository

Zirconium alloys are widely used in the core of various types of nuclear reactors. During service, the hot water coolant reacts with zirconium and releases hydrogen atoms that ingress into the lattice of the metal alloy. With time, hydrogen concentration exceeds its terminal solid solubility limit in zirconium, and a brittle phase known as zirconium hydride forms. This phase severely deteriorates the mechanical properties of zirconium alloys, leading to safety concerns regarding the integrity of nuclear pressure tubes. This thesis uses a crystal plasticity finite element model coupled with diffusion equations to study the effects of localized deformation at the …

Considering The Influence Of Coronary Motion On Artery‑Specific Biomechanics Using Fluid–Structure Interaction Simulation, Nicholas A. T. Fogell, Miten Patel, Pan Yang, Roosje M. Ruis, David B. Garcia, Jarka Naser, Fotios Savvopoulos, Clint Davies Taylor, Anouk L. Post, Ryan M. Pedrigi, Ranil De Silva, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The endothelium in the coronary arteries is subject to wall shear stress and vessel wall strain, which influences the biology of the arterial wall. This study presents vessel-specific fluid–structure interaction (FSI) models of three coronary arteries, using directly measured experimental geometries and boundary conditions. FSI models are used to provide a more physiologically complete representation of vessel biomechanics, and have been extended to include coronary bending to investigate its effect on shear and strain. FSI both without- and with-bending resulted in significant changes in all computed shear stress metrics compared to CFD (p = 0.0001). Inclusion of bending within …

A Threshold Helium Leakage Detection Switch With Ultra Low Power Operation, Sulaiman Mohaidat, Fadi M. Alsaleem

Department of Mechanical and Materials Engineering: Faculty Publications

Detecting helium leakage is important in many applications, such as in dry cask nuclear waste storage systems. This work develops a helium detection system based on the relative permittivity (dielectric constant) difference between air and helium. This difference changes the status of an electrostatic microelectromechanical system (MEMS) switch. The switch is a capacitive-based device and requires a very negligible amount of power. Exciting the switch’s electrical resonance enhances the MEMS switch sensitivity to detect low helium concentration. This work simulates two different MEMS switch configurations: a cantilever-based MEMS modeled as a single-degreefreedom model and a clamped-clamped beam MEMS molded using …

Crystalline–Amorphous Nanostructures: Microstructure, Property And Modelling, Binqiang Wei, Lin Li, Lin Shao, Jian Wang

Department of Mechanical and Materials Engineering: Faculty Publications

Crystalline metals generally exhibit good deformability but low strength and poor irradiation tolerance. Amorphous materials in general display poor deformability but high strength and good irradiation tolerance. Interestingly, refining characteristic size can enhance the flow strength of crystalline metals and the deformability of amorphous materials. Thus, crystalline–amorphous nanostructures can exhibit an enhanced strength and an improved plastic flow stability. In addition, high-density interfaces can trap radiation-induced defects and accommodate free volume fluctuation. In this article, we review crystalline–amorphous nanocomposites with characteristic microstructures including nanolaminates, core–shell microstructures, and crystalline/amorphous-based dual-phase nanocomposites. The focus is put on synthesis of characteristic microstructures, deformation …

Plasmon Enhanced Quantum Properties Of Single Photon Emitters With Hybrid Hexagonal Boron Nitride Silver Nanocube Systems, Mohammadjavad Dowran, Andrew Butler, Suvechhya Lamichhane, Adam Erickson, Ufuk Kilic, Sy_Hwang Liou, Christos Argyropoulos, A. Laraoui

Department of Mechanical and Materials Engineering: Faculty Publications

Hexagonal boron nitride (hBN) has emerged as a promising ultrathin host of single photon emitters (SPEs) with favorable quantum properties at room temperature, making it a highly desirable element for integrated quantum photonic networks. One major challenge of using these SPEs in such applications is their low quantum efficiency. Recent studies have reported an improvement in quantum efficiency by up to two orders of magnitude when integrating an ensemble of emitters such as boron vacancy defects in multilayered hBN flakes embedded within metallic nanocavities. However, these experiments have not been extended to SPEs and are mainly focused on multiphoton effects. …

Physics-Based Crystal Plasticity Model For Predicting Microstructure Evolution And Dislocation Densities, Juyoung Jeong

LSU Doctoral Dissertations

This work presents three different studies investigating plastic deformation mechanisms in metals and alloys using crystal plasticity finite element (CPFE) modeling. The first study presents a new nonlocal crystal plasticity model for face-centered cubic single crystals under heterogeneous inelastic deformation. The model incorporates generalized constitutive relations that incorporate the thermally activated and drag mechanisms to cover different kinetics of viscoplastic flow in metals and describes the plastic flow and yielding of single-crystals using dislocation densities. The model is compared to micropillar compression experiments for copper single crystals and clarifies the complex microstructural evolution of dislocation densities in metals. The second …

Graphene Twistronics: Tuning The Absorption Spectrum And Achieving Metamaterial Properties, Ammar Armghan, Meshari Alsharari, Khaled Aliqab, Osamah Alsalman, Juveriya Parmar, Shobhit K. Patel

Department of Mechanical and Materials Engineering: Faculty Publications

Graphene twistronics using multilayer graphene is presented in such a way that it provides a metamaterial effect. This manuscript also analyzes the prediction of behavior using machine learning. The metamaterial effect is achieved by twisting the graphene layers. Graphene twistronics is a new concept for changing the electrical and optical properties of bilayer graphene by applying a small angle twist between the layers. The angle twists of 5^o, 10^o, and 15^o are analyzed for the proposed graphene twistronics design. Tuning in the absorption spectrum is achieved by applying small twists to the angles of the …

Heterogeneous Sensor Data Fusion For Multiscale, Shape Agnostic Flaw Detection In Laser Powder Bed Fusion Additive Manufacturing, Benjamin Bevans, Christopher Barrett, Thomas Spears, Aniruddha Gaikwad, Alex Riensche, Harold (Scott) Halliday, Prahalada Rao

Department of Mechanical and Materials Engineering: Faculty Publications

We developed and applied a novel approach for shape agnostic detection of multiscale flaws in laser powder bed fusion (LPBF) additive manufacturing using heterogenous in-situ sensor data. Flaws in LPBF range from porosity at the micro-scale (< 100 μm), layer related inconsistencies at the meso-scale (100 μm to 1 mm) and geometry-related flaws at the macroscale (> 1 mm). Existing data-driven models are primarily focused on detecting a specific type of LPBF flaw using signals from one type of sensor. Such approaches, which are trained on data from simple cuboid and cylindrical-shaped coupons, have met limited success when used for detecting multiscale flaws in complex LPBF parts. The objective of this work is to develop a heterogenous sensor data fusion …

Precious Plastics - Plastic Brick Machine Fabrication, Timothy Ukaobasi Kanu, Evi Paraskevi Troulis

Architectural Engineering

The goal of this research is to determine the structural parameters of the recycled plastic polypropylene when molded into bricks resembling CMU blocks. To accomplish this, three mechanisms had to be assembled: the shredder, the injector, and the 1x1 mold. A tensile and compression test were to be performed on the plastic brick, and the values would be used to compare the tensile and compressive strength of PP plastic bricks, as well as their modulus of elasticity and stress vs. Strain performance. These values would be analyzed to determine whether it would be feasible to build an entire plastic wall. …

Interfaces In Dynamic Brittle Fracture Of Pmma: A Peridynamic Analysis, Longzhen Wang, Javad Mehrmashhadi, Florin Bobaru

Department of Mechanical and Materials Engineering: Faculty Publications

Recent experiments in bonded PMMA layers have shown dramatic changes in dynamic crack growth characteristics depending on the interface location and toughness. In this paper we present a peridynamic (PD) analysis of this phenomenon and determine three elements that are essential in a model reproducing the observed fracture behavior: (1) softening near the crack tip to account for changes in PMMA due to heat-generation induced by the high strain rates reached around the crack tip in dynamic fracture; (2) independent extension (mode I) and shear (mode II) modes of fracture; (3) a two-parameter fracture model, which matches both strength and …

Effect Of Blank Moisture Content On Forming Behaviour And Mechanical Properties Of Paperboard Tray Packages, Arvo Niini, Lena Berthold, Tobias Müller, Panu Tanninen, Jens-Peter Majschak, Juha Varis, Ville Leminen

Journal of Applied Packaging Research

Tray blanks were moisturised to study the effect of different blank moisture content levels on forming behaviour and mechanical properties of paperboard tray packages. The blank moisturisation was done by spraying water to the blanks before their three-dimensional (3D) forming. The trays were 3D formed by press forming or deep drawing. Visual quality and punch force values were used as indicators to evaluate the forming behaviour of the trays. The mechanical properties of the trays were investigated with compression, torsion, and storing tests. A high blank moisture content reduced the punch force, and the elevated blank moisture was connected to …