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Articles 1 - 30 of 45
Full-Text Articles in Engineering
Trading Off Sound Pressure Level And Average Power Production For Wind Farm Layout Optimization, Eric Tingey, Andrew Ning
Trading Off Sound Pressure Level And Average Power Production For Wind Farm Layout Optimization, Eric Tingey, Andrew Ning
Faculty Publications
This research explores the trade-offs between a wind farm’s average power production and noise impact on nearby observers. Two specific wind farm designs were studied and optimized using the FLORIS wake model and an acoustic model based on semi-empirical turbine noise calculations. It was found in the two wind farms that the average power production could be increased, up to 8.01% in one and 3.63% in the other, ignoring sound level considerations. Including a noise restriction in the optimization had a minimal impact on the optimal average power production within about a five-decibel range. Past this range, sound limitations decreased …
Reaching In Clutter With Whole-Arm Tactile Sensing, Advait Jain, Marc D. Killpack, Aaron Edsinger, Charles Kemp
Reaching In Clutter With Whole-Arm Tactile Sensing, Advait Jain, Marc D. Killpack, Aaron Edsinger, Charles Kemp
Faculty Publications
Clutter creates challenges for robot manipulation, including a lack of non-contact trajectories and reduced visibility for line-of-sight sensors. We demonstrate that robots can use whole-arm tactile sensing to perceive clutter and maneuver within it, while keeping contact forces low. We first present our approach to manipulation, which emphasizes the benefits of making contact across the entire manipulator and assumes the manipulator has low-stiffness actuation and tactile sensing across its entire surface. We then present a novel controller that exploits these assumptions. The controller only requires haptic sensing, handles multiple contacts, and does not need an explicit model of the environment …
Relationships Between Access To Mobile Devices, Student Self-Directed Learning, And Achievement, Scott R. Bartholomew, Ed Reeve, Raymond Veon, Wade Goodridge, Victor Lee, Louis Nadelson
Relationships Between Access To Mobile Devices, Student Self-Directed Learning, And Achievement, Scott R. Bartholomew, Ed Reeve, Raymond Veon, Wade Goodridge, Victor Lee, Louis Nadelson
Faculty Publications
Today’s students are growing up in a world of constant connectivity, instant information, and ever-changing technological advancements. The increasingly ubiquitous nature of mobile devices among K–12 students has led many to argue for and against the inclusion of these devices in K–12 classrooms. Arguments in favor cite instant access to information and collaboration with others as positive affordances that enable student self-directed learning. In this study, 706 middle school students from 18 technology and engineering education classes worked in groups of 2–3 to complete an openended engineering design challenge. Students completed design portfolios and constructed prototypes in response to the …
Combined Model Predictive Control And Scheduling With Dominant Time Constant Compensation, Logan Beal, Junho Park, Damon Petersen, Sean C. Warnick, John Hedengren
Combined Model Predictive Control And Scheduling With Dominant Time Constant Compensation, Logan Beal, Junho Park, Damon Petersen, Sean C. Warnick, John Hedengren
Faculty Publications
Linear model predictive control is extended to both control and optimize a product grade schedule. The proposed methods are time-scaling of the linear dynamics based on throughput rates and grade-based objectives for product scheduling based on a mathematical program with complementarity constraints. The linear model is adjusted with a residence time approximation to time-scale the dynamics based on throughput. Although nonlinear models directly account for changing dynamics, the model form is restricted to linear differential equations to enable fast online cycle times for large-scale and real-time systems. This method of extending a linear time-invariant model for scheduling is designed for …
Deep Visual Gravity Vector Detection For Unmanned Aircraft Attitude Estimation, Gary J. Ellingson, David Wingate, Tim Mclain
Deep Visual Gravity Vector Detection For Unmanned Aircraft Attitude Estimation, Gary J. Ellingson, David Wingate, Tim Mclain
Faculty Publications
This paper demonstrates a feasible method for using a deep neural network as a sensor to estimate the attitude of a flying vehicle using only flight video. A dataset of still images and associated gravity vectors was collected and used to perform supervised learning. The network builds on a previously trained network and was trained to be able to approximate the attitude of the camera with an average error of about 8 degrees. Flight test video was recorded and processed with a relatively simple visual odometry method. The aircraft attitude is then estimated with the visual odometry as the state …
Relative Multiplicative Extended Kalman Filter For Observable Gps-Denied Navigation, Daniel P. Koch, David O. Wheeler, Randal Beard, Tim Mclain, Kevin M. Brink
Relative Multiplicative Extended Kalman Filter For Observable Gps-Denied Navigation, Daniel P. Koch, David O. Wheeler, Randal Beard, Tim Mclain, Kevin M. Brink
Faculty Publications
This work presents a multiplicative extended Kalman filter for estimating the relative state of a multirotor vehicle operating in a GPS-denied environment. The filter fuses data from an inertial measurement unit and altimeter with relative-pose updates from a keyframe-based visual odometry or laser scan-matching algorithm. Because the global position and heading states of the vehicle are unobservable in the absence of global measurements such as GPS, the filter in this paper estimates the state with respect to a local frame that is colocated with the odometry keyframe. As a result, the odometry update provides nearly-direct measurements of the relative vehicle …
Relative Navigation Of Autonomous Gps-Degraded Micro Air Vehicles, David O. Wheeler, Daniel P. Koch, James S. Jackson, Gary J. Ellingson, Paul W. Nyholm, Timothy W. Mclain, Randal W. Beard
Relative Navigation Of Autonomous Gps-Degraded Micro Air Vehicles, David O. Wheeler, Daniel P. Koch, James S. Jackson, Gary J. Ellingson, Paul W. Nyholm, Timothy W. Mclain, Randal W. Beard
Faculty Publications
Many current approaches for navigation of micro air vehicles (MAVs) in GPS-degraded environments use a globally-referenced state for estimation and control, even though this state is not observable when GPS is unavailable. By working with respect to a local reference frame, the relative navigation (RN) framework presented in this paper ensures that the state maintains observability and that the uncertainty remains bounded, consistent, and normally-distributed. RN further insulates flight-critical estimation and control processes from the large global updates common in GPS-degraded MAV flight. This paper provides a thorough description of the details needed to successfully implement the RN framework on …
Improving The Floris Wind Plant Model For Compatibility With Gradient-Based Optimization, Jared Thomas, Pieter Gebraad, Andrew Ning
Improving The Floris Wind Plant Model For Compatibility With Gradient-Based Optimization, Jared Thomas, Pieter Gebraad, Andrew Ning
Faculty Publications
The FLOw Redirection and Induction in Steady-state (FLORIS) model, a parametric wind turbine wake model that predicts steady state wake characteristics based on wind turbine position and yaw angle, was developed for optimization of control settings and turbine locations. This paper provides details on the recent changes made to the FLORIS model to make the model more suitable for gradient-based optimization. Changes to the FLORIS model were made to remove discontinuities and add curvature to regions of non-physical zero gradient. Exact gradients for the FLORIS model were obtained using algorithmic differentiation. A set of three case studies demonstrate that using …
Custom 3d Printer And Resin For 18 Μm × 20 Μm Mi- Crofluidic Flow Channels, Hua Gong, Bryce P. Bickham, Adam T. Woolley, Gregory P. Nordin
Custom 3d Printer And Resin For 18 Μm × 20 Μm Mi- Crofluidic Flow Channels, Hua Gong, Bryce P. Bickham, Adam T. Woolley, Gregory P. Nordin
Faculty Publications
While there is great interest in 3D printing for microfluidic device fabrication, to-date the achieved feature sizes have not been in the truly microfluidic regime (μm). In this paper we demonstrate that a custom Digital Light Processor stereolithographic (DLP-SLA) 3D printer and a specifically-designed, low cost, custom resin can readily achieve flow channel cross sections as small as 18 μm × 20 μm. Our 3D printer has a projected image plane resolution of 7.6 μm and uses a 385 nm LED, which dramatically increases the available selection of UV absorbers for resin formulation compared to 3D printers with 405 nm …
Minimum Required Detection Range For Detect And Avoid Of Unmanned Aircraft Systems, Jared Kevin Wikle, Tim Mclain, Randal W. Beard, Laith Rasmi Sahawneh
Minimum Required Detection Range For Detect And Avoid Of Unmanned Aircraft Systems, Jared Kevin Wikle, Tim Mclain, Randal W. Beard, Laith Rasmi Sahawneh
Faculty Publications
For unmanned aircraft systems to gain full access to the National Airspace System, they must have the capability to detect and avoid other aircraft. To safely avoid an- other aircraft, an unmanned aircraft must detect the intruder aircraft with ample time and distance to allow the ownship to track the intruder, perform risk assessment, plan an avoidance path, and execute the maneuver. This paper describes two analytical methods for finding the minimum detection range to ensure that these detection and avoidance steps can be carried out. The first method, time-based geometric velocity vectors, includes the bank-angle dynamics of the ownship; …
Thermophysical Properties Of Thin Fibers Via Photothermal Quantum Dot Fluorescence Spectral Shape-Based Thermometry, Troy Munro, Liwang Liu, Heng Ban, Christ Glorieux
Thermophysical Properties Of Thin Fibers Via Photothermal Quantum Dot Fluorescence Spectral Shape-Based Thermometry, Troy Munro, Liwang Liu, Heng Ban, Christ Glorieux
Faculty Publications
To improve predictions of composite behavior under thermal loads, there is a need to measure the axial thermophysical properties of thin fibers. Current methods to accomplish this have prohibitively long lead times due to extensive sample preparation. This work details the use of quantum dots thermomarkers to measure the surface temperature of thin fibers in a non-contact manner and determine the fibers’ thermal diffusivity. Neural networks are trained on extracting the temperature of a sample from fluorescence spectra in calibrated, steady-state conditions, based on different spectral features such as peak intensity and peak wavelength. The trained neural networks are then …
Estimating Human Intent For Physical Human-Robot Co-Manipulation, Eric Townsend, Erich Mielke, David Wingate, Marc D. Killpack
Estimating Human Intent For Physical Human-Robot Co-Manipulation, Eric Townsend, Erich Mielke, David Wingate, Marc D. Killpack
Faculty Publications
Human teams can be exceptionally efficient at adapting and collaborating during manipulation tasks using shared mental models. However, the same shared mental models that can be used by humans to perform robust low-level force and motion control during collaborative manipulation tasks are non-existent for robots. For robots to perform collaborative tasks with people naturally and efficiently, understanding and predicting human intent is necessary. However, humans are difficult to predict and model. We have completed an exploratory study recording motion and force for 20 human dyads moving an object in tandem in order to better understand how they move and how …
Microstructure Correlation With Formability For Biaxial Stretching Of Magnesium Alloy Az31b At Mildly Elevated Temperatures, David T. Fullwood, Isaac Chelladurai, Michael P. Miles, John E. Carsley, Raj K. Mishra, Irene J. Beyerlein, Marko Knezevic
Microstructure Correlation With Formability For Biaxial Stretching Of Magnesium Alloy Az31b At Mildly Elevated Temperatures, David T. Fullwood, Isaac Chelladurai, Michael P. Miles, John E. Carsley, Raj K. Mishra, Irene J. Beyerlein, Marko Knezevic
Faculty Publications
Magnesium AZ31B sheets of 2 mm thickness were stretch formed using a 101.6 mm diameter punch at temperatures from 25°C - 150°C, in 25°C increments. Surface strains were measured using a digital image correlation (DIC) method. The punch height vs load curve was found to be the same for temperatures of 25°C and for 50°C, while at 75°C and above the load for a given punch height started to decrease, indicating a potential change in deformation mechanism. Electron Backscatter Diffraction (EBSD) was used to quantify features of the microstructure in the tested specimens. In particular, the gradual decrease in twinning …
Potential Benefits Of Combining Anomaly Detection With View Planning For Uav Infrastructure Modeling, R. Abraham Martin, Landen Blackburn, Joshua Pulsipher, Kevin W. Franke, John Hedengren
Potential Benefits Of Combining Anomaly Detection With View Planning For Uav Infrastructure Modeling, R. Abraham Martin, Landen Blackburn, Joshua Pulsipher, Kevin W. Franke, John Hedengren
Faculty Publications
This paper presents a novel method for UAV-based 3D modeling of large infrastructure objects, such as pipelines, canals and levees, that combines anomaly detection with automatic on-board 3D view planning. The study begins by assuming that anomaly detections are possible and focuses on quantifying the potential benefits of the combined method and the view planning algorithm. A simulated canal environment is constructed, and several simulated anomalies are created and marked. The algorithm is used to plan inspection flights for the anomaly locations, and simulated images from the flights are rendered and processed to construct 3D models of the locations of …
Designing The Technological World Through Biomimicry, Emily Yoshikawa, Greg J. Strimel, Scott R. Bartholomew
Designing The Technological World Through Biomimicry, Emily Yoshikawa, Greg J. Strimel, Scott R. Bartholomew
Faculty Publications
Scientific discoveries are a driver for advancing our technological world (ITEA/ITEEA; 2000/2002/2007). As more knowledge is acquired through scientific inquiry, people can better design and develop technological inventions and innovations (Knowles, Kelley, & Hurd, 2016). In turn, these novel technologies can aid in making new scientific discoveries, thus driving an ongoing cycle of technological advancement. However, in the process of designing and advancing our technological world, people can turn to the study of life and its phenomena to inspire and inform their designs. Nature is functional as well as beautiful. As we study the phenomena or functions of living organisms …
Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning
Optimization Under Uncertainty For Wake Steering Strategies, Julian Quick, Jennifer Annoni, Ryan King, Katherine Dykes, Paul Fleming, Andrew Ning
Faculty Publications
Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence …
Engaging Children In Engineering Design Through The World Of Quadcopters, Greg J. Strimel, Scott R. Bartholomew, Eunhye Kim
Engaging Children In Engineering Design Through The World Of Quadcopters, Greg J. Strimel, Scott R. Bartholomew, Eunhye Kim
Faculty Publications
The interest in engineering education for K-12 students has been rising (Carr, Bennett IV, & Strobel, 2012; Strimel, Grubbs, & Wells, 2016), and the importance of engineering education is discussed as early as the elementary school level (Hegedus, 2014). Petroski (2003) claims that children are ready to learn engineering because their play activities are similar to engineering and design activities, such as making, moving, and rearranging things. Studies have examined how elementary school students perceive engineering or engineers (Cunningham, Lachapelle, & Lindgren-Streicher 2005) and found that elementary-aged students associated engineering with repairing, installing, driving, constructing, and improving machines and devices. …
Surface Acoustic Wave Based Pumping In A Microchannel, Tao Wang, Qi Ni, Nathan B. Crane, Rasim Guldiken
Surface Acoustic Wave Based Pumping In A Microchannel, Tao Wang, Qi Ni, Nathan B. Crane, Rasim Guldiken
Faculty Publications
Pumping and manipulation of liquids in microfluidic channels is important for many mechanical, chemical and biomedical applications. Surface acoustic wave based devices fabricated on high-efficiency piezoelectric substrates have been recently investigated for mixing and separation application within microfluidic channels. In this paper, we introduce a novel integrated surface acoustic wave based pump for liquid delivery and precise manipulation within a microchannel. The device employs a hydrophobic surface coating (Cytop) in the device design for decreasing the friction force and increasing the bonding. Contrary to previous surface acoustic wave based pump, this device does not need precise layers of water and …
Thermal Characterization Of Natural And Synthetic Spider Silks By Both The 3Ω And Transient Electrothermal Methods, Troy Munro, Changhu Xing, Heng Ban, Cameron G. Copeland, Randolph V. Lewis, Colby Jensen
Thermal Characterization Of Natural And Synthetic Spider Silks By Both The 3Ω And Transient Electrothermal Methods, Troy Munro, Changhu Xing, Heng Ban, Cameron G. Copeland, Randolph V. Lewis, Colby Jensen
Faculty Publications
Thermal conductivity, thermal diffusivity and volumetric heat capacity of three spider silks are measured in this paper as a benchmark for further studies. These silks include the major and minor ampullate silks of the Nephila clavipes spider, and a synthetic spider silk fiber made from recombinant dragline silk proteins purified from transgenic goats’ milk. Two complementary measurement techniques are employed in the thermal characterization of these microscale single fibers for self-verification. One is the transient electrothermal technique (TET) and the other is the 3ω method. Experimental measurements indicate that thermal properties of the dragline silk are very close to those …
Investigation Of Synthetic Spider Silk Crystallinity And Alignment Via Electrothermal, Pyroelectric, Literature Xrd, And Tensile Techniques, Troy Munro, Tristan Putzeys, Michael Wubbenhorst, Christ Glorieux, Cameron G. Copeland, Randolph V. Lewis, Changhu Xing, Heng Ban
Investigation Of Synthetic Spider Silk Crystallinity And Alignment Via Electrothermal, Pyroelectric, Literature Xrd, And Tensile Techniques, Troy Munro, Tristan Putzeys, Michael Wubbenhorst, Christ Glorieux, Cameron G. Copeland, Randolph V. Lewis, Changhu Xing, Heng Ban
Faculty Publications
The processes used to create synthetic spider silk greatly affect the properties of the produced fibers. This paper investigates the effect of process variations during artificial spinning on the thermal and mechanical properties of the produced silk. Property values are also compared to the ones of the natural dragline silk of the N. clavipes spider, and to unprocessed (as-spun) synthetic silk. Structural characterization by scanning pyroelectric microscopy is employed to provide insight into the axial orientation of the crystalline regions of the fiber and is supported by XRD data. The results show that stretching and passage through liquid baths induce …
A Multi-Fluid Model For Microstructure Formation In Polymer Membranes, Douglas R. Tree, Kris T. Delaney, Hector D. Ceniceros, Tatsuhiro Iwama, Glenn H. Fredrickson
A Multi-Fluid Model For Microstructure Formation In Polymer Membranes, Douglas R. Tree, Kris T. Delaney, Hector D. Ceniceros, Tatsuhiro Iwama, Glenn H. Fredrickson
Faculty Publications
We develop a multi-fluid model for a ternary polymer solution using the Rayleighian formalism of Doi and Onuki, and give an efficient pseudo-spectral method for solving both the diffusion and momentum equations that result. Subsequently, we find that the numerical simulation is capable of describing systems at the micron length-scale and easily reaches millisecond time-scales. In addition, we characterize the model thermodynamics and kinetics including the (i) phase behavior, (ii) structure of the interfaces, (iii) mutual diffusion coefficients, (iv) bulk spinodal decomposition kinetics with and without hydrodynamics and (v) spinodal decomposition in the presence of an interface with a non-solvent …
Two-Phase Flow Pressure Drop In Superhydrophobic Channels, Kimberly A. Stevens, Julie Crockett, Daniel R. Maynes, Brian D. Iverson
Two-Phase Flow Pressure Drop In Superhydrophobic Channels, Kimberly A. Stevens, Julie Crockett, Daniel R. Maynes, Brian D. Iverson
Faculty Publications
Superhydrophobic surfaces have been shown to reduce drag in single-phase channel flow; however, little work has been done to characterize their drag-reducing ability found in two-phase flows. Adiabatic, airwater mixtures were used to explore the influence of hydrophobicity on two-phase flows and the hydrodynamics which might be present in flow condensation environments. Pressure drop measurements in a rectangular channel with one superhydrophobic wall (cross-section approximately 0.37 x 10 mm) and three transparent hydrophilic walls were obtained. Data for air/water mixtures with superficial Reynolds numbers ranging from 22–215 and 55–220, respectively, were obtained for superhydrophobic surfaces with three different cavity fractions. …
Influence Of Noise Generating Factors On Cross Correlation Ebsd Measurement Of Gnds, David T. Fullwood, Landon Hansen, Brian Jackson, Stewart I. Wright, Marc De Graef, Eric Richards Homer, Robert Wagoner
Influence Of Noise Generating Factors On Cross Correlation Ebsd Measurement Of Gnds, David T. Fullwood, Landon Hansen, Brian Jackson, Stewart I. Wright, Marc De Graef, Eric Richards Homer, Robert Wagoner
Faculty Publications
Studies of dislocation density evolution are fundamental to improved understanding in various areas of deformation mechanics. Recent advances in cross-correlation techniques, applied to EBSD data have particularly shed light on geometrically necessary dislocation (GND) behavior. However, the framework is relatively computationally expensive – patterns are typically saved from the EBSD scan and analyzed offline. A better understanding of the impact of EBSD pattern degradation, such as binning, compression, and various forms of noise, is vital to enable optimization of rapid and low cost GND analysis. This paper tackles the problem by setting up a set of simulated patterns that mimic …
Binder-Jet Printing Of Fine Stainless Steel Powder With Varied Final Density, Mohsen Ziaee, Eric M. Tridas, Nathan B. Crane
Binder-Jet Printing Of Fine Stainless Steel Powder With Varied Final Density, Mohsen Ziaee, Eric M. Tridas, Nathan B. Crane
Faculty Publications
Binder jetting is an additive manufacturing process that produces relatively weak porous parts that are strengthened through sintering and/or infiltration. This paper reports on two different methods of preparing fine 316 stainless steel powder and their impact on the final sintered density and dimensions relative to direct printing into -22 micron powder. The first method uses agglomerates of fine powder. In the second, nylon 12 powders are mixed with the steel powder as a fugitive space holder to increase porosity. Sintered density and sintering shrinkage of agglomerate material are shown to vary with the density of the spread powder bed. …
Analysis Of Rigid Extended Object Co-Manipulation By Human Dyads: Lateral Movement Characterization, Erich Mielke, Eric Townsend, Marc D. Killpack
Analysis Of Rigid Extended Object Co-Manipulation By Human Dyads: Lateral Movement Characterization, Erich Mielke, Eric Townsend, Marc D. Killpack
Faculty Publications
During co-manipulation involving humans and robots, it is necessary to base robot controllers on human behaviors to achieve comfortable and coordinated movement between the human-robot dyad. In this paper, we describe an experiment between human-human dyads and we record the force and motion data as the leader-follower dyads moved in translation and rotation. The force/motion data was then analyzed for patterns found during lateral translation only. For extended objects, lateral translation and in-place rotation are ambiguous, but this paper determines a way to characterize lateral translation triggers for future use in human-robot interaction. The study has 4 main results. First, …
Integrated Stem Through Tumblewing Gliders, Scott R. Bartholomew
Integrated Stem Through Tumblewing Gliders, Scott R. Bartholomew
Faculty Publications
Teachers have the opportunity to use technology and engineering design problems to engage students in integrated STEM education. “Tumblewing” gliders are easy-to-make paper gliders that can challenge, excite, and engage students. As students emphasize the practices of science and engineering while completing a tumblewing design challenge, they will engage in both scientific inquiry and the engineering design process.
A Well Clear Recommendation For Small Uas In High-Density, Ads-B-Enabled Airspace, Timothy Mclain, Matthew O. Duffield
A Well Clear Recommendation For Small Uas In High-Density, Ads-B-Enabled Airspace, Timothy Mclain, Matthew O. Duffield
Faculty Publications
With the growing popularity of small unmanned aircraft systems (UAS), there is a significant need to enable small UAS to detect and avoid collisions with both manned and unmanned aircraft. The capabilities of ADS-B make it an attractive sensor for detect and avoid (DAA), but it is susceptible to frequency congestion. This paper quantitatively analyzes the frequency limitations of 978 MHz ADS-B. It then uses these limitations to make a recommendation for well clear in ADS-B-equipped airspace that has a high density of small UAS operations.
Hybrid Concentrated Solar Thermal Power Systems: A Review, Kody M. Powell, Khalid Rashid, Kevin Ellingwood, Jake Tuttle, Brian D. Iverson
Hybrid Concentrated Solar Thermal Power Systems: A Review, Kody M. Powell, Khalid Rashid, Kevin Ellingwood, Jake Tuttle, Brian D. Iverson
Faculty Publications
Concentrated solar power (CSP), or solar thermal power, is an ideal technology to hybridize with other energy technologies for power generation. CSP shares technology with conventional power generation and can be readily integrated with other energy types into a synergistic system, which has many potential benefits including increased dispatchability and reliability, improved efficiency, reduced capital costs through equipment sharing, and the opportunity for flexible operation by alternating between energy sources. Another advantage of CSP technology is the ability to readily store via thermal energy storage (TES), making the intermittent solar resource dispatchable. A review of CSP hybridization strategies with coal, …
Enhancing Ductility Of Wwr Slabs, Mohamed Shwani, Taylor J. Sorensen, Ethan Pickett, Parker Syndergaard, Marc Maguire
Enhancing Ductility Of Wwr Slabs, Mohamed Shwani, Taylor J. Sorensen, Ethan Pickett, Parker Syndergaard, Marc Maguire
Faculty Publications
A series of research studies have recently identified an issue called strain localization in welded wire reinforced (WWR) members. This phenomenon reportedly concentrates strains at welded cross wire locations and severely limit ductility. Those that identified the phenomenon used it to imply that WWR is unsafe because it does not warn of failure. This research program is investigating details to mitigate the strain localization effect and demonstrate the WWR can be used safely. Sixteen beams have been constructed using WWR and rebar with various cross wire spacing, using a realistic design. The strain localization phenomenon was not demonstrated, but WWR …
Developing A General Methodology For Evaluating Composite Action In Insulated Wall Panels, Taylor Sorensen
Developing A General Methodology For Evaluating Composite Action In Insulated Wall Panels, Taylor Sorensen
Faculty Publications
Precast concrete sandwich wall panels (PCSWPs) have been in use for over 60 years. They provide a very efficient building envelope for many buildings. Characteristic PCSWPs comprise an outer and inner layer (or wythe) of concrete separated by an insulating material. To use all of the material as efficiently as possible, the layers are attached by connectors which penetrate through the insulating layer and are embedded in either concrete wythe. These connectors make it possible for both layers of the wall to work together when resisting loads. The connectors are made out of plastic, or FRP, to prevent heat transfer …