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Articles 6271 - 6300 of 33648
Full-Text Articles in Entire DC Network
Control Of A Three-Phase Grid-Connected Inverter Under Non-Ideal Grid Conditions With Online Parameter Update, Vikram Roy Chowdhury, Jonathan W. Kimball
Control Of A Three-Phase Grid-Connected Inverter Under Non-Ideal Grid Conditions With Online Parameter Update, Vikram Roy Chowdhury, Jonathan W. Kimball
Electrical and Computer Engineering Faculty Research & Creative Works
Three-phase grid-connected inverter modeling depends on the equivalent resistance and inductance between the inverter and the grid. However, these parameters are not fixed during the operation of the inverter and vary with the operating conditions. In this paper, a new globally stable adaptive controller is proposed to estimate these values online and update the controller during its operation. A model reference adaptive system (MRAS) based on two fictitious quantities with no physical significance is utilized, namely M = v · i∗ and N = v∗ x i, where v and i are the steady-state values of voltage and current in …
Strong Circular Dichroism In Chiral Plasmonic Metasurfaces Optimized By Micro-Genetic Algorithm, Zhigang Li, Daniel Rosenmann, David A. Czaplewski, Xiaodong Yang, Jie Gao
Strong Circular Dichroism In Chiral Plasmonic Metasurfaces Optimized By Micro-Genetic Algorithm, Zhigang Li, Daniel Rosenmann, David A. Czaplewski, Xiaodong Yang, Jie Gao
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Strong circular dichroism in absorption in the near-infrared wavelength range is realized by designing binary-pattern chiral plasmonic metasurfaces via the micro-genetic algorithm optimization method. The influence of geometric parameter modifications in the binary-pattern nanostructures on the circular dichroism performance is studied. The strong circular dichroism in absorption is attributed to the simultaneous excitation and field interference of the resonant modes with relative phase delay under linearly polarized incident light. This work provides a universal design method toward the on-demand properties of chiral metasurfaces, which paves the way for future applications in chemical and biological sensing, chiral imaging and spectroscopy.
The Default-Mode Network Represents Aesthetic Appeal That Generalizes Across Visual Domains, Edward A. Vessel, Ayse Ilkay Isik, Amy M. Belfi, Jonathan L. Stahl, G. Gabrielle Starr
The Default-Mode Network Represents Aesthetic Appeal That Generalizes Across Visual Domains, Edward A. Vessel, Ayse Ilkay Isik, Amy M. Belfi, Jonathan L. Stahl, G. Gabrielle Starr
Psychological Science Faculty Research & Creative Works
Visual aesthetic evaluations, which impact decision-making and well-being, recruit the ventral visual pathway, subcortical reward circuitry, and parts of the medial prefrontal cortex overlapping with the default-mode network (DMN). However, it is unknown whether these networks represent aesthetic appeal in a domain-general fashion, independent of domain-specific representations of stimulus content (artworks versus architecture or natural landscapes). Using a classification approach, we tested whether the DMN or ventral occipitotemporal cortex (VOT) contains a domain-general representation of aesthetic appeal. Classifiers were trained on multivoxel functional MRI response patterns collected while observers made aesthetic judgments about images from one aesthetic domain. Classifier performance …
Influence Of Guayule Resin As A Bio-Based Additive On Asphalt-Rubber Binder At Elevated Temperatures, Ahmed Hemida, Magdy Abdelrahman
Influence Of Guayule Resin As A Bio-Based Additive On Asphalt-Rubber Binder At Elevated Temperatures, Ahmed Hemida, Magdy Abdelrahman
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This study seeks to find the influence of replacing a portion of the asphalt–rubber binder with the bio-based material “guayule resin.” This replacement could be beneficial in terms of sustainability, economics, and environmental concerns related to the asphalt industry. Nine asphalt-rubber-guayule binders were investigated to find their rheological properties. Consecutively, the study proceeded with five selected binders being compared to the original asphalt (PG64-22). Investigations underwent whole matrices (crumb rubber modifier (CRM) residue included) and liquid phases (CRM residue extracted). Additionally, these properties were partially sought for their corresponding asphalt–rubber binders to compare and judge the contribution of the guayule …
Rare But Conceivable: Determining The Likelihood Of Meteors And Other Infrequent Events, Michael S. Schmidt, Maria Vega-Westhoff
Rare But Conceivable: Determining The Likelihood Of Meteors And Other Infrequent Events, Michael S. Schmidt, Maria Vega-Westhoff
Engineering Management and Systems Engineering Faculty Research & Creative Works
In the aftermath of a rare but devastating disaster, there is a tendency to overestimate how frequent such an event may be, hence a tendency to overestimate the risk associated with such an event. Those concerned with process safety will acknowledge that though rare, events like meteors, hurricanes, and airplane crashes that can impact chemical plants are conceivable. Typically, though, they have nothing more than feelings to decide whether these events are likely enough to be considered "credible." This compiles data from the literature for several "meteors," both natural and man-made, that often become a cause of general concern after …
Reliability-Based Design Optimization Of Load Sharing Systems Using Ssi-Markov Models, Arun Bala Subramaniyan, Rong Pan, Xiaoping Du
Reliability-Based Design Optimization Of Load Sharing Systems Using Ssi-Markov Models, Arun Bala Subramaniyan, Rong Pan, Xiaoping Du
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper presents a novel single loop approach to design the components of the load sharing systems by optimally allocating the failure probabilities to each component, thereby satisfying the overall system reliability requirement. The Reliability–Based Design Optimization (RBDO) of load sharing systems is computationally intensive due to the dynamic nature of component failure probabilities, since the failure of one component will vary the failure probabilities of other working components. Many RBDO methods have been successfully utilized to design individual components, however using these methods for handling system level reliability constraints is still a challenging task. This is because of a …
The Potential Of Using Micro-Sized Crosslinked Polymer Gel To Remediate Water Leakage In Cement Sheaths, Murad Abdulfarraj, Abdulmohsin Imqam
The Potential Of Using Micro-Sized Crosslinked Polymer Gel To Remediate Water Leakage In Cement Sheaths, Murad Abdulfarraj, Abdulmohsin Imqam
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Cementing is a major step in the construction and sealing of hydrocarbon wells. During the life cycle of the well, cement is prone to cracking due to a change in downhole conditions. This research investigates the use of micro-sized crosslinked polymer gel as a sealant material to mitigate cracked cement sheaths. Two experimental setups were designed to investigate water leakage through cement. The impact of polymer gel strength on the gel's ability to seal cement cracks was investigated using four gel strengths, including 500 pa, 1200 pa, 1450 pa, and 2440 pa. The impact of the width of the cement …
Evaluation Of A 38 L Explosive Chamber For Testing Coal Dust Explosibility, Robert Eades, Kyle A. Perry
Evaluation Of A 38 L Explosive Chamber For Testing Coal Dust Explosibility, Robert Eades, Kyle A. Perry
Mining Engineering Faculty Research & Creative Works
Coal dust explosions are the deadliest disasters facing the coal mining industry. Research has been conducted globally on this topic for decades. The first explosibility tests in the United States were performed by the Bureau of Mines using a 20 L chamber. This serves as the basis for all standardized tests used for combustible dusts. The purpose of this paper is to investigate the use of a new 38 L chamber for testing coal dust explosions. The 38 L chamber features design modifications to model the unique conditions present in an underground coal mine when compared to other industries where …
Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk
Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk
Materials Science and Engineering Faculty Research & Creative Works
The material science of additive manufacturing (AM) has become a significant topic due to the unique way in which the material and geometry are created simultaneously. Major areas of research within inorganic materials include traditional structural materials, shape memory alloys, amorphous materials, and some new work in intermetallics. The unique thermal profiles created during selective laser melting (SLM) may provide new opportunities for processing intermetallics to improve mechanical and magnetic performance. A parameter set for the production of Fe-Co-2V material with additive manufacturing is developed and efforts are made to compare the traditional wrought alloy to the AM version of …
Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo's First Two Observing Runs, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Directional Limits On Persistent Gravitational Waves Using Data From Advanced Ligo's First Two Observing Runs, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We perform an unmodeled search for persistent, directional gravitational wave (GW) sources using data from the first and second observing runs of Advanced LIGO. We do not find evidence for any GW signals. We place limits on the broadband GW flux emitted at 25 Hz from point sources with a power law spectrum at Fα,Θ < (0.05-25) x 10−8 erg cm−2 s−1 Hz−1 and the (normalized) energy density spectrum in GWs at 25 Hz from extended sources at Ωα(Θ) < (0.19-2.89) x 10−8 sr−1 where α is the spectral index of the energy density spectrum. These represent improvements of …
Erratum: Searches For Gravitational Waves From Known Pulsars At Two Harmonics In 2015-2017 Ligo Data (Astrophysical Journal (2019) 879 (10) Doi: 10.3847/1538-4357/Ab20cb), B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Erratum: Searches For Gravitational Waves From Known Pulsars At Two Harmonics In 2015-2017 Ligo Data (Astrophysical Journal (2019) 879 (10) Doi: 10.3847/1538-4357/Ab20cb), B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Due to an error at the publisher, in the published article the number of pulsars presented in the paper is incorrect in multiple places throughout the text. Specifically, "222" pulsars should be "221." Additionally, the number of pulsars for which we have EM observations that fully overlap with O1 and O2 changes from "168" to "167." Elsewhere, in the machine-readable table of Table 1 and in Table 2, the row corresponding to pulsar J0952-0607 should be excised as well. Finally, in the caption for Table 2 the number of pulsars changes from "188" to "187." IOP Publishing sincerely regrets this …
Search For The Isotropic Stochastic Background Using Data From Advanced Ligo's Second Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For The Isotropic Stochastic Background Using Data From Advanced Ligo's Second Observing Run, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
The stochastic gravitational-wave background is a superposition of sources that are either too weak or too numerous to detect individually. In this study, we present the results from a cross-correlation analysis on data from Advanced LIGO's second observing run (O2), which we combine with the results of the first observing run (O1). We do not find evidence for a stochastic background, so we place upper limits on the normalized energy density in gravitational waves at the 95% credible level of ΩGW < 6.0 x 10-8 for a frequency-independent (flat) background and ΩGW < 4.8 x 10-8 at 25 Hz for a background of compact …
Search For Intermediate Mass Black Hole Binaries In The First And Second Observing Runs Of The Advanced Ligo And Virgo Network, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Intermediate Mass Black Hole Binaries In The First And Second Observing Runs Of The Advanced Ligo And Virgo Network, B. P. Abbott, R. Abbott, T. D. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Gravitational-wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar-mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational waves from intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network. The search uses three independent algorithms: two based on matched filtering of the data with waveform templates of gravitational-wave signals from compact binaries, and a third, model-independent algorithm that employs no signal model for the incoming signal. No intermediate mass black hole binary event …
A Dynamical (E,2e) Investigation Into The Ionization Of The Outermost Orbitals Of R-Carvone, D. B. Jones, E. Ali, C. G. Ning, F. Ferreira Da Silva, O. Ingolfsson, M. C. A. Lopes, H. S. Chakraborty, Don H. Madison, M. J. Brunger
A Dynamical (E,2e) Investigation Into The Ionization Of The Outermost Orbitals Of R-Carvone, D. B. Jones, E. Ali, C. G. Ning, F. Ferreira Da Silva, O. Ingolfsson, M. C. A. Lopes, H. S. Chakraborty, Don H. Madison, M. J. Brunger
Physics Faculty Research & Creative Works
We report an experimental and theoretical investigation into the dynamics of electron-impact ionization of R-carvone. Experimental triple differential cross sections are obtained in asymmetric coplanar kinematic conditions for the ionization of the unresolved combination of the three outermost molecular orbitals (41a-39a) of R-carvone. These cross sections are compared with theoretical cross sections calculated within a molecular 3-body distorted wave (M3DW) framework employing either a proper orientation average or orbital average to account for the random orientation of the molecule probed in the experiment. Here, we observe that the overall scattering behavior observed in the experiment is fairly well reproduced within …
Scholars' Mine Quick Facts August 2019, Nancy S. Krost
Scholars' Mine Quick Facts August 2019, Nancy S. Krost
Scholars’ Mine Statistics
Scholars' Mine Quick Facts are monthly reports of downloads, page hits, and other information about works in the institutional repository of Missouri S&T. A map with downloads by region is also included.
Correlated Quantum Dynamics Of Two Quenched Fermionic Impurities Immersed In A Bose-Einstein Condensate, Simeon I. Mistakidis, L. Hilbig, P. Schmelcher
Correlated Quantum Dynamics Of Two Quenched Fermionic Impurities Immersed In A Bose-Einstein Condensate, Simeon I. Mistakidis, L. Hilbig, P. Schmelcher
Physics Faculty Research & Creative Works
We Unravel The Nonequilibrium Dynamics Of Two Fermionic Impurities Immersed In A One-Dimensional Bosonic Gas Following An Interspecies Interaction Quench. Monitoring The Temporal Evolution Of The Single-Particle Density Of Each Species We Reveal The Existence Of Four Distinct Dynamical Regimes. For Weak Interspecies Repulsions Both Species Either Perform A Breathing Motion Or The Impurity Density Splits Into Two Parts Which Interact And Disperse Within The Bosonic Cloud. Turning To Strong Interactions We Observe The Formation Of Dark-Bright States Within The Mean-Field Approximation. However, The Correlated Dynamics Shows That The Fermionic Density Splits Into Two Repelling Density Peaks Which Either Travel …
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Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert
Lactonic Sophorolipid Increases Surface Wettability Of Poly- L -Lactic Acid Electrospun Fibers, Alexis M. Ziemba, Keith P. Lane, Bailey Balouch, Anthony R. D'Amato, Filbert Totsingan, Richard A. Gross, Ryan J. Gilbert
Chemical and Biochemical Engineering Faculty Research & Creative Works
The hydrophobicity of electro spun poly-l-lactic acid (PLLA) fibers hinders their integration with surrounding tissue for a variety of applications. In this study, we increased PLLA fiber hydrophilicity by incorporating the natural surfactant, lactonic sophorolipid (LSL). PLLA+LSL fibers had similar fiber morphology but significantly greater surface wettability, which suggested LSL accumulation on the fiber surface. Differential scanning calorimetry results also suggested that LSL was phase separated from PLLA. Despite the altered surface wettability of these fibers, there was no change in fibroblast adhesion. Future studies may explore the use of this natural surfactant to deliver bioactive factors to enhance fibroblast …
Spontaneous Generation Of Dark-Bright And Dark-Antidark Solitons Upon Quenching A Particle-Imbalanced Bosonic Mixture, H. Kiehn, Simeon I. Mistakidis, Garyfallia C. Katsimiga, P. Schmelcher
Spontaneous Generation Of Dark-Bright And Dark-Antidark Solitons Upon Quenching A Particle-Imbalanced Bosonic Mixture, H. Kiehn, Simeon I. Mistakidis, Garyfallia C. Katsimiga, P. Schmelcher
Physics Faculty Research & Creative Works
We Unveil The Dynamical Formation Of Multiple Localized Structures In The Form Of Dark-Bright And Dark-Antidark Solitary Waves That Emerge Upon Quenching A One-Dimensional Particle-Imbalanced Bose-Bose Mixture. Interspecies Interaction Quenches Drive The System Out Of Equilibrium While The So-Called Miscible-Immiscible Threshold Is Crossed In A Two-Directional Manner. Dark-Bright Entities Are Spontaneously Generated For Quenches Towards The Phase Separated Regime And Dark-Antidark States Are Formed In The Reverse Process. The Distinct Mechanisms Of Creation Of The Aforementioned States Are Discussed In Detail And Their Controlled Generation Is Showcased. In Both Processes, It Is Found That The Number Of Solitary Waves Generated …
Elevated Temperature Mechanical And Microstructural Characterization Of Slm Ss304l, G. R. Hecht, Sriram Praneeth Isanaka, Joseph William Newkirk
Elevated Temperature Mechanical And Microstructural Characterization Of Slm Ss304l, G. R. Hecht, Sriram Praneeth Isanaka, Joseph William Newkirk
Materials Science and Engineering Faculty Research & Creative Works
SLM built SS304L was annealed and water quenched to minimize residual stress and avoid carbide precipitation. Mini-tensile characterization of strength and elongation at temperature conditions up to 800°C, along with observations of the associated microstructural transformations were utilized to understand the changes produced in SLM SS304L. As-built and annealed specimens were found to exhibit decreasing strength and elongation with increasing temperature as expected. Carbide precipitates appeared after short times at high temperatures within both as-built and annealed specimens for all cases, but no brittle intermetallic phase development was observed for any of the temperatures investigated. While the lack of Sigma, …
Frequency Inspection Of Additively Manufactured Parts For Layer Defect Identification, Aimee Allen, Kevin Johnson, Jason R. Blough, Andrew Barnard, Troy Hartwig, Ben Brown, David Soine, Tristan Cullom, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel
Frequency Inspection Of Additively Manufactured Parts For Layer Defect Identification, Aimee Allen, Kevin Johnson, Jason R. Blough, Andrew Barnard, Troy Hartwig, Ben Brown, David Soine, Tristan Cullom, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Additive manufactured (AM) parts are produced at low volume or with complex geometries. Identifying internal defects is difficult as current testing techniques are not optimized for AM processes. The goal of this paper is to evaluate defects on multiple parts printed on the same build plate. The technique used was resonant frequency testing with the results verified through Finite Element Analysis. From these tests, it was found that the natural frequencies needed to detect the defects were higher than the excitation provided by a modal hammer. The deficiencies in this range led to the development of other excitation methods. Based …
Joining Of Copper And Stainless Steel 304l Using Direct Metal Deposition, Xinchang Zhang, Yitao Chen, Tan Pan, Wenyuan Cui, Lan Li, Frank W. Liou
Joining Of Copper And Stainless Steel 304l Using Direct Metal Deposition, Xinchang Zhang, Yitao Chen, Tan Pan, Wenyuan Cui, Lan Li, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In the current study, the feasibility of joining pure copper (Cu) and stainless steel 304L (SS304L) through direct metal deposition process was investigated by material characterization. Samples were analyzed in terms of microstructure, elemental distribution, and tensile testing. Direct depositing pure copper on SS304L shows copper was mechanically rather than metallurgical bonded with SS304L due to the poor dissolubility of iron in copper. Iron was diffused into copper with a diluted distance of 1.5 mm and above that, pure copper deposits were obtained. Columnar structure was observed at the copper region near the interface while the columnar grains became finer …
Simulated Effect Of Laser Beam Quality On The Robustness Of Laser-Based Am System, Aaron Flood, Frank W. Liou
Simulated Effect Of Laser Beam Quality On The Robustness Of Laser-Based Am System, Aaron Flood, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
In many metal AM techniques, a laser is used as the heat source and in some applications, it can be advantageous to work off of the focal plane. When operating outside of focus, the beam quality of the laser can have drastic impacts on the ability to manufacture quality parts. This study investigates the effect of the beam quality and distance from the focal plan on the ability to deposit Ti-64, aluminum, and steel through the simulation of the blown powder process.
In-Situ Local Part Qualification Of Slm 304l Stainless Steel Through Voxel Based Processing Of Swir Imaging Data, Cody S. Lough, Xin Wang, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, Edward C. Kinzel
In-Situ Local Part Qualification Of Slm 304l Stainless Steel Through Voxel Based Processing Of Swir Imaging Data, Cody S. Lough, Xin Wang, Robert G. Landers, Douglas A. Bristow, James A. Drallmeier, Edward C. Kinzel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This paper demonstrates the potential for qualification through local part property prediction of 304L stainless steel parts manufactured by Selective Laser Melting (SLM). This is accomplished through voxel based processing of SWIR imaging data measured in-situ. Thermal features are extracted from time-series SWIR imaging data recorded from layer-to-layer to generate 3D point cloud reconstructions of parts. The voxel based data is indexed with localized measurements of SLM part properties (light-to-dark microstructural feature ratio, microhardness, μCT data) to demonstrate the correlations. Various features are extracted from the thermal history for comparison of their respective abilities to predict the resulting local part …
Effective Elastic Properties Of Additively Manufactured Metallic Lattice Structures: Unit-Cell Modeling, Okanmisope Fashanu, David Murphy, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Ben Brown, John Porter
Effective Elastic Properties Of Additively Manufactured Metallic Lattice Structures: Unit-Cell Modeling, Okanmisope Fashanu, David Murphy, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Ben Brown, John Porter
Materials Science and Engineering Faculty Research & Creative Works
Lattice structures are lightweight materials, which exhibit a unique combination of properties such as air and water permeability, energy and acoustic absorption, low thermal conductivity, and electrical insulation. In this work, unit-cell homogenization was used to predict the effective elastic moduli of octet-truss (OT) lattice structures manufactured using selective laser melting (SLM). OT structures were manufactured using a Renishaw AM 250 SLM machine with various relative densities. Compression test was carried out at strain rate 5 x 10-3 m-1 using an MTS frame. Finite element analysis was used in the determination of the OT’s effective elastic properties. Results …
Dynamic Defect Detection In Additively Manufactured Parts Using Fea Simulation, Kevin Johnson, Aimee Allen, Jason R. Blough, Andrew Barnard, David Labyak, Troy Hartwig, Ben Brown, David Soine, Tristan Cullom, Edward C. Kinzel, Douglas A. Bristow, Robert G. Landers
Dynamic Defect Detection In Additively Manufactured Parts Using Fea Simulation, Kevin Johnson, Aimee Allen, Jason R. Blough, Andrew Barnard, David Labyak, Troy Hartwig, Ben Brown, David Soine, Tristan Cullom, Edward C. Kinzel, Douglas A. Bristow, Robert G. Landers
Mechanical and Aerospace Engineering Faculty Research & Creative Works
The goal of this paper is to evaluate internal defects in additively manufactured (AM) parts using FEA simulation. The resonant frequencies of parts are determined by the stiffness and mass involved in the mode shape at each resonant frequency. Voids in AM parts will change the stiffness and mass therefore shift the resonant frequencies from nominal. This paper will investigate the use of FEA to determine how much a void size, shape, and location will change the resonant frequencies. Along with where the optimal input and response locations are in order to find these frequency changes. The AM part evaluated …
Frequency Domain Measurements Of Melt Pool Recoil Pressure Using Modal Analysis And Prospects For In-Situ Non-Destructive Testing, Tristan Cullom, Nicholas Altese, Douglas A. Bristow, Robert G. Landers, Ben Brown, Troy Hartwig, David Soine, Aimee Allen, Andrew Barnard, Jason Blough, Kevin Johnson, Edward C. Kinzel
Frequency Domain Measurements Of Melt Pool Recoil Pressure Using Modal Analysis And Prospects For In-Situ Non-Destructive Testing, Tristan Cullom, Nicholas Altese, Douglas A. Bristow, Robert G. Landers, Ben Brown, Troy Hartwig, David Soine, Aimee Allen, Andrew Barnard, Jason Blough, Kevin Johnson, Edward C. Kinzel
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Fielding Additively Manufactured (AM) parts requires evaluating both the part’s geometry and material state. This includes geometry that may be optically hidden. Both the geometry and material state affect the vibration response of the parts and modal analysis (identifying natural frequencies) has been shown to be effective for at least simple geometries using ex-situ methods (shaker table and impact hammer excitations). This paper investigates evaluation of the frequency response of metal parts inside the build chamber using the process laser to excite the parts during printing (Renishaw AM250). Vibrations in the part are measured with accelerometers connected to the build …
The Effect Of Cell Size And Surface Roughness On The Compressive Properties Of Abs Lattice Structures Fabricated By Fused Deposition Modeling, Leah Mason, Ming-Chuan Leu
The Effect Of Cell Size And Surface Roughness On The Compressive Properties Of Abs Lattice Structures Fabricated By Fused Deposition Modeling, Leah Mason, Ming-Chuan Leu
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Researchers looking to improve the surface roughness of acrylonitrile butadiene styrene (ABS) parts fabricated by fused deposition modeling (FDM) have determined that acetone smoothing not only achieves improved surface roughness but increases compressive strength as well. However, the sensitivity of ABS parts to acetone smoothing has not been explored. In this study we investigated FDM-fabricated ABS lattice structures of various cell sizes subjected to cold acetone vapor smoothing to determine the combined effect of cell size and acetone smoothing on the compressive properties of the lattice structures. The acetone-smoothed specimens performed better than the as-built specimens in both compression modulus …
Application Of Schlieren Technique In Additive Manufacturing: A Review, R. Bharadwaja, Aravind Murugan, Yitao Chen, Frank W. Liou
Application Of Schlieren Technique In Additive Manufacturing: A Review, R. Bharadwaja, Aravind Murugan, Yitao Chen, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Additive manufacturing has gained a lot of attention in the past few decades due to its significant advantages in terms of design freedom, lower lead time, and ability to produce complex shapes. One of the pivotal factors affecting the process stability and hence the part quality is the shielding gas flow in additive manufacturing. As extremely beneficial for the process, the shielding gas flow is often set at maximum supply to achieve enough gas cover over the substrate. This causes excessive quantity of shielding gas to be unutilized. Realizing the importance of shielding gas, various studies have been carried out …
Applications Of Supervised Machine Learning Algorithms In Additive Manufacturing: A Review, M. S. Joshi, Aaron Flood, Todd E. Sparks, Frank W. Liou
Applications Of Supervised Machine Learning Algorithms In Additive Manufacturing: A Review, M. S. Joshi, Aaron Flood, Todd E. Sparks, Frank W. Liou
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Additive Manufacturing (AM) simplifies the fabrication of complex geometries. Its scope has rapidly expanded from the fabrication of pre-production visualization models to the manufacturing of end use parts driving the need for better part quality assurance in the additively manufactured parts. Machine learning (ML) is one of the promising techniques that can be used to achieve this goal. Current research in this field includes the use of supervised and unsupervised ML algorithms for quality control and prediction of mechanical properties of AM parts. This paper explores the applications of supervised learning algorithms - Support Vector Machines and Random Forests. Support …