Structural Materials Commons^™

Microstructure Design Using Graphs, Pengfei Du, Adrian Zebrowski, Jaroslaw Zola, Baskar Ganapathysubramanian, Olga Wodo

Mechanical Engineering Publications

Thin films with tailored microstructures are an emerging class of materials with applications such as battery electrodes, organic electronics, and biosensors. Such thin film devices typically exhibit a multi-phase microstructure that is confined, and show large anisotropy. Current approaches to microstructure design focus on optimizing bulk properties, by tuning features that are statistically averaged over a representative volume. Here, we report a tool for morphogenesis posed as a graph-based optimization problem that evolves microstructures recognizing confinement and anisotropy constraints. We illustrate the approach by designing optimized morphologies for photovoltaic applications, and evolve an initial morphology into an optimized morphology exhibiting ...

Solid Solution Strengthened Fe Alloys, Sidharth Krishnamoorthi, Ruizhe Su, Yifan Zhang, Xinghang Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Iron (Fe)-based alloys (such as steel) are widely used structural materials in industry. Numerous methods have been applied to improve their mechanical properties. In this study, we used a technique know as magnetron sputtering to deposit various Fe-based binary alloy coatings to investigate the influence of solutes on solid solution hardening. Several factors contribute to the solid solution hardening of the alloys, such as composition, atomic radius, modulus, and lattice parameter. After preliminary calculations and analysis, we selected several solutes, including molybdenum (Mo), niobium (Nb), and zirconium (Zr). The compositions of solutes were varied to be 2.5, 5 ...

Thermophotovoltaic Devices: Combustion Chamber Optimization And Modelling To Maximize Fuel Efficiency, Arnold Chris Toppo, Ernesto Marinero, Zhaxylyk Kudyshev

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, 110 billion cubic meters of natural gas (primarily methane), a potent greenhouse gas, are flared off for environmental and safety reasons. This process results in enough fuel to provide the combined natural gas consumption of Germany and France. The research team developed a thermophotovoltaic device to convert thermal energy to electricity at a high efficiency using proprietary emitters and combustion system. With the current focus being fuel efficiency and the combustion process, the assembly was simulated using ANSYS Fluent modelling software and the following parameters were optimized: air/fuel ratios, flow rates, and inlet sizes. Simultaneously the heat transfer ...

High Performance Mortar With 100% Recycled Aggregate Using Titanium Dioxide Nanoparticles, Molly Schrager, Vito Francioso, Arjun Kadakia, Mirian Velay-Lizancos

The Summer Undergraduate Research Fellowship (SURF) Symposium

Concrete and mortar are materials commonly used in construction. Their main compounds are cement, aggregates (sand and gravel) and water. In an effort to increase the sustainability of these materials, the idea of using recycled aggregates from ground old concrete and using it to make mortar and concrete has gained more interest. It has two advantages: it reduces the need to mine for raw materials and lessens the amount of old and defective concrete that is typically put in landfills. But, the use of recycled concrete aggregate lowers the strength of mortars and concretes because the residual compounds in the ...

Determining The Optimal Traffic Opening Time Using Piezoelectric Sensors, Adlan Amran, Yen-Fang Su, Na Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Indiana Department of Transportation (INDOT) requires a reliable method of determining the early age quality of concrete to improve traffic opening time. We propose to develop an in-situ method that enables an accurate, efficient, and non-destructive health monitoring of concrete using the electromechanical impedance (EMI) technique coupled with a piezoelectric sensor named Lead Zirconate Titanate (PZT). The test was conducted by mounting a PZT sensor on mortar samples. The PZT sensor was then excited by a voltage to track the strengthening of samples. The data obtained from the EMI technique was refined using the Root Mean Square Deviation (RMSD ...

Design Survey Of Laminated Composite I-Beam, Mrinmoy Saha

All Graduate Plan B and other Reports

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing ...

Improving And Augmenting The Anm Model For Three-Dimensional Virtual Concrete, Stephen Thomas

Boise State University Theses and Dissertations

The Anm model used for creating virtual concrete consisting of irregular shapes has been improved by integrating two existing algorithms: the extent overlap box (EOB) method for detecting contact between two irregular shapes and the uniform thickness shell algorithm. The EOB method has been compared with the previously used Newton-Raphson method and shown to be able to detect inter-particle contact with better accuracy and with less computational cost. Two parameters that define the balance between accuracy and performance of the EOB method have been identified and studied. The uniform thickness shell has been used to specify the minimum inter-particle distance ...

Otta Seal Construction For Asphalt Pavement Resurfacing, Sharif Y. Gushgari, Yang Zhang, Ali Nahvi, Halil Ceylan, Sunghwan Kim

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Otta seal resurfacing methods have been widely demonstrated for unpaved roads and road rehabilitation in a few states in the U.S. as well as in Scandinavia and Africa. Application of Otta seal over a deteriorated hot mix asphalt (HMA) surface has been considered as the feasible concept that has not been applied for real construction. In this study, a double-layer Otta seal construction over HMA surface was monitored. The applied materials for the construction were introduced. The following performance of the constructed Otta seal layers was evaluated by measuring the international roughness index (IRI) and dust. The road IRI ...

Investigating The Heat Generation Efficiency Of Electrically-Conductive Asphalt Mastic Using Infrared Thermal Imaging, Ali Arabzadeh, Halil Ceylan, Sunghwan Kim, Alireza Sassani, Kasthurirangan Gopalakrishnan

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

One of the emerging technologies for producing sustainable ice-and snow-free pavements is the use of electrically-conductive surface courses, e.g., electrically-conductive asphalt concrete (ECAC) that can melt ice and snow through resistive heating. Modifying the mastic in asphalt concrete with electrically-conductive materials is a promising approach for producing high-quality ECAC. The objective of this study is to evaluate electrical conductivity and heat generation efficiency of electrically-conductive asphalt mastic (ECAM) specimens at a below-freezing temperature—simulating the harsh weather conditions in North America during the wintertime. To this end, asphalt mastic was electrically modified with carbon fiber (CF) at varying volume ...

Development Of Artificial Neural Networks Based Predictive Models For Dynamic Modulus Of Airfield Pavement Asphalt Mixtures, Orhan Kaya, Navneet Garg, Halil Ceylan, Sunghwan Kim

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

As part of asphalt mix design for flexible airfield pavements, the Federal Aviation Administration (FAA) collects asphalt volumetric mixture properties and aggregate gradations. Binder properties as well as laboratory dynamic modulus |E*| measurements for asphalt mixes are performed for flexible airfield pavements research. An artificial neural networks (ANN) model was developed using collected volumetric properties, aggregate gradation, and binder properties as well as laboratory |E*| measurements from seven hot-mix asphalt (HMA) and warm mix asphalt (WMA) mixtures. ANN model predictions were compared with the modified Witczak predictive model calculations for the same mixtures, and it was found that the developed ...

Hydronic Heated Pavement System Using Precast Concrete Pavement For Airport Applications, Hesham Abdualla, Halil Ceylan, Sunghwan Kim, Peter C. Taylor, Kasthurirangan Gopalakrishnan, Kristen Cetin

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

The use of deicing chemical has the potential to cause environmental and safety concerns and pavement deterioration. Hydronic heated pavement systems (HHPS) have been widely used to melt or prevent ice and snow accumulation on paved surfaces. HHPS uses heated fluid circulated through pipes embedded in the concrete pavement to warm the surface of the concrete. The objective of this study is to develop a conceptual design framework and construction guidance for large-scale HHPS using precast concrete pavement (PCP) technology to expedite construction work and minimize air travel disruption. The detailed design and 3-D visualization of construction procedures has been ...

Aftershocks In Slowly Compressed Bulk Metallic Glasses: Experiments And Theory, Louis W. Mcfaul, Wendelin Wright, Xiaojun Gu, Jonathan T. Uhl, Karin A. Dahmen

Faculty Journal Articles

We observe two distinct interevent time patterns in the slip avalanches of compressed bulk metallic glasses (BMGs). Small slip avalanches cluster together in time, but large slip avalanches recur roughly periodically. We compare the timing patterns of BMG slip avalanches with timing patterns of earthquakes and with the predictions of a mean-field model. The time clustering of small avalanches is similar to the known time clustering of earthquake foreshocks and aftershocks.

Microstructural Characterization Of Shear Transformation Zones And Modeling Indentation Size Effect In Amorphous Polymers, Leila Malekmotiei

LSU Doctoral Dissertations

The first aim of this work is developing a procedure for experimental and analytical characterization of nano-scale microstructures which mediate large scale deformation in amorphous polymers. Glassy polymers are extensively used as high impact resistant, low density, and clear materials in industries. Nevertheless, their response under severe loading conditions is yet to be appropriately unraveled. Due to the lack of long-range order in the microstructures of glassy solids, their plastic deformation is different from that in crystalline solids. Shear Transformation Zones (STZs) are believed to be the main plasticity carriers in amorphous solids and defined as the localized atomic or ...

Development Of Test Methods For Measuring Fiber Misalignment And Warping In Honeycomb-Core Composite Panels, Wyatt Taylor, Haripriya Nilakantan

Materials Engineering

Zodiac Aerospace manufactures honeycomb-core composite panels to be used in aircraft cabin interior components. During the manufacturing process, some panels become warped such that they cannot be used for their designated aircraft cabin components. As a result, these panels are scrapped because they cannot be recycled. About 44 to 90% of panels become warped during manufacturing. Warping is caused by many factors, including layer misalignment, processing parameters such as temperature and pressure gradients, and fiber misalignment in the prepregs. Currently, Zodiac does not have any data on the effect of fiber misalignment on panel warpage, so a testing protocol was ...

Anomalous 304 Stainless Steel Mechanical Properties In Medical Guide Wires, Andrew Joseph Freeman

Materials Engineering

Stainless steel medical guide wire cores, processed by Abbott Vascular, are returning anomalous mechanical properties upon strain hardening and heat treatment. As theory dictates, mechanical strength properties increase with strain hardening, and decrease with an annealing treatment. The opposite response is being observed. This is counter intuitive to fundamental materials knowledge, and a perfect materials engineering paradox. This project was designed to characterize these behaviors, and attempt to determine causation. To accomplish this, tensile testing of all processing steps mapped the mechanical property evolution of the wire. Published literature research revealed the potential of nitrogen and chromium solid state diffusion ...

Composite Suspension For A Mass Market Vehicle, Sarah M. Chapiama, Brian Auyeung, Jose Guerrero, Ethan Lau

Mechanical Engineering

No abstract provided.

Adaptive Observers For Structural Health Monitoring Of High-Rate, Time-Varying Dynamic Systems, B. S. Joyce, J. Hong, J. C. Dodson, J. C. Wolfson, Simon Laflamme

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Safe and reliable operation of hypersonic aircraft, space structures, advanced weapon systems, and other high-rate dynamic systems depends on advances in state estimators and damage detection algorithms. High-rate dynamic systems have rapidly changing input forces, rate-dependent and time-varying structural parameters, and uncertainties in material and structural properties. While current structural health monitoring (SHM) techniques can assess damage on the order of seconds to minutes, complex high-rate structures require SHM methods that detect, locate, and quantify damage or changes in the structure’s configuration on the microsecond timescale.

This paper discusses the importance of microsecond structural health monitoring (μSHM) and some ...

Investigation Of Nanomaterial Based Photovoltaic Panel Packaging Materials, Xingeng Yang

Theses and Dissertations

In this research, nanomaterial-based packaging materials for photovoltaic (PV) panels are investigated. A hydrophobic/anti-reflective surface coating which not only repels water from the top glass of a PV panel but at the same time reduces its light reflectance is investigated. COMSOL simulation results indicate that taller ellipsoid rod (aspect ratio = 5) reflects less light than shorter rod (aspect ratio = 0.5) in the desired spectrum for solar energy harvest from 400nm-700nm. The addition of a polymer layer on these ellipsoid rods broadens the light incident angle from 23° to 34°, from which light can be efficiently absorbed. Based on ...

Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler

Public Land and Resources Law Review

In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also ...

A True Self-Supportive Structure, Connor Kaldor

Undergraduate Research Symposium

Self-supportive concrete shells are a harmonious mix of utilitarian materiality and inspiring form. Structurally stable, beautiful, and easy to conceptualize; Most shells structures can be derived from simplistic exercises and accurately represented by scaled models. These structures are something truly special but despite the great achievements of lightweight shell structures, they still require one unfortunate necessity. A shell structure often requires intensive form work or scaffolding to facilitate the construction process. Some solutions exist like cable-stayed key stones or streamlined versions of what we know as scaffolding. While nominally effective, these solutions fall short of the achievements of what they ...