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A preliminary study of the electrical and interlaminar shear properties of a porous CFRP composite laminate containing carbon nanofiber Z-threads 6

A preliminary study of the electrical and interlaminar shear...

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6th Annual Composites and Advanced Materials Expo, CAMX 2019

作者： Kirmse, Sebastian Ranabhat, Bikash Hsiao, Kuang-Ting University of South Alabama Mobile AL36688 United States Systems Engineering Program United States Department of Mechanical Engineering United States

In this study, a porous carbon fiber/epoxy nanocomposite (P-ZT-CFRP) containing a low concentration of z-threaded carbon nanofibers was manufactured. DC electrical conductivity measurements and interlaminar shear tests were performed on the porous nanocomposite. It was hypothesized that the CNFs interlock and connect multiple arrays of carbon fibers using a connecting agent (i.e., resin) at contact locations between the CNFs and carbon fibers, which provides additional strength to the otherwise weak porous composite laminate while making it extremely conductive. The through-thickness DC electrical conductivity was increased by 2840% (9.37 S/m) and 2971% (9.81 S/m) for the unidirectional porous nanocomposite laminate containing 0.85wt% and 2.0wt% of CNF z-threads, respectively, when compared to a traditional carbon fiber reinforced polymer (CFRP) (0.33 S/m). Void characterization showed that the void content in the matrix for the porous nanocomposites was at least 20%, which satisfies the definition of a porous nanocomposite [1]. The interlaminar shear strength of the 0.85wt% CNF z-threaded P-ZT-CFRP with a fiber volume fraction of around 80% was about 50% higher than for a P-CFRP without CNFs. Furthermore, the porous nanocomposite showed good potential in overcoming the effects of void on the mechanical properties of CFRPs. Using the rule of mixture, the P-ZT-CFRP shows a ~10.5% increase in longitudinal tensile strength and modulus when compared to a traditional CFRP. It was concluded that the material has high potential but will require additional research and research collaborations between industry partners to develop a possible next-generation multi-functional nanocomposite. © 2019 by Ever J. Barbero. Published by CAMX - The Composites and Advanced Materials Expo.

关键词： Carbon nanofibers

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The z-directional dc electrical conductivity of carbon nanofiber z-threaded porous cfrp composites manufactured by radial flow alignment technique

The z-directional dc electrical conductivity of carbon nanof...

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International SAMPE Conference and Exhibition 2020

作者： Ranabhat, Bikash Kirmse, Sebastian Johnson, Michael Hsiao, Kuang-Ting University of South Alabama Department of Mechanical Engineering 150 Jaguar Drive Shelby Hall Suite 3130 MobileAL36608 United States Department of Mechanical Engineering United States Systems Engineering Program

The non-conductive polymer matrix impedes carbon fiber's excellent electrical conductivity in the carbon fiber reinforced polymer (CFRP) composites. Due to its low z-directional DC electrical conductivity, CFRP composites has limited application capabilities in lightning strike protection (LSP) and electromagnetic shielding. This research demonstrates the ability to manufacture lightweight and electrically conductive (i.e., z-direction) CNFs z-threaded porous CFRP composite utilizing just 50 % of epoxy used in the traditional composites. In this study, the radial flow alignment technique was used to z-thread carbon nanofibers (CNFs) into the carbon fiber fabric. Experimental results showed the z-directional DC electrical conductivity in the 0.85 wt% CNF z-threaded porous (P-ZT-CFRP) was 21.06 S/m, which is an increase of 778 % and 107 % compared to the traditional composite sample and P-CFRP (without nano-reinforcement) laminate, respectively. © 2020 Soc. for the Advancement of Material and Process engineering. All rights reserved.

关键词： Carbon nanofibers

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Potential of SERS for rapid detection of melamine and cyanuric acid extracted from milk

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Sensing and Instrumentation for Food Quality and Safety 2010年第1期4卷 13-19页

作者： Liu, Bin Lin, Mengshi Li, Hao Food Science Program Division of Food Systems and Bioengineering University of Missouri Columbia MO 65211 United States Department of Mechanical and Aerospace Engineering University of Missouri Columbia MO 65211 United States

Melamine, a nitrogen-rich chemical, was implicated in the pet and human food recalls in 2007 and in the global food safety scares in 2008 involving milk and other milk-derived products. In this study, we investigated the feasibility of using surface-enhanced Raman spectroscopy (SERS) coupled with SERS-active gold substrates for rapid detection of trace amounts of melamine and its analogue (that is, cyanuric acid) in liquid milk. Raman signals of tested samples were significantly enhanced by SERS. The identification limit for SERS using gold substrate can reach 2 ppm of melamine in liquid milk. Partial least squares (PLS) models were established for the quantification of melamine in liquid milk by SERS: R = 0.90, RMSEP = 1.48 × 10-5. Our results demonstrate that rapid detection of melamine in milk can be achieved by SERS;while detection of cyanuric acid in milk remains a challenging task due to rapid enol-keto tautomerism of cyanuric acid. The SERS method is faster and simpler than other traditional methods, and requires minimum sample preparation. These results demonstrate that SERS could be used to detect food contaminants such as melamine in foods and food ingredients quickly and accurately. © 2009 Springer Science+Business Media, LLC.

关键词： Substrates

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FPGA implementation of the EKF algorithm for localization in mobile robotics using a unified hardware module approach

FPGA implementation of the EKF algorithm for localization in...

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International Conference on ReConFigurable Computing and FPGAs, ReConFig 2015

作者： Contreras, Luis Cruz, Sergio Motta, J.M.S.T. Llanos, Carlos H. Graduate Program in Mechatronic Systems Department of Mechanical Engineering University of Brasilia Brasilia D.F.70910-900 Brazil

ISBN: (纸本)9781467394062

In this paper a Hardware Architecture for computing the Extended Kalman Filter (EKF) is presented which is addressed to solve the self-localization problem of autonomous mobile robots. In this case, the overall EKF algorithm has been implemented in hardware over an Altera Cyclone IV FPGA with a Nios II processor, in which the latter is used only for interfacing and communication tasks. The achieved implementation has been adapted and applied to the mobile platform Pioneer 3AT (P3AT) for validation task. The prediction stage of the EKF algorithm was based on a dead-reckoning system model and the estimation stage on a measurement system which uses a sensor of Laser Range Finder (LRF). The proposed architecture has been designed considering a Unified Hardware Module approach using floating-point arithmetic operators, allowing the operations to be computed with large precision and dynamic range. Furthermore, several metrics have been used to evaluate the system performance, measuring both FPGA resources consumption, power consumption and execution time. Finally, the suitability of reconfigurable devices for such kind of applications has been verified and also discussed. © 2015 IEEE.

关键词： Field programmable gate arrays (FPGA)

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Sub-optimal Perceptron Controller Using WOA Algorithm for Farming Watering Mobile Robot

Sub-optimal Perceptron Controller Using WOA Algorithm for Fa...

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2024 IEEE Latin American Conference on Computational Intelligence, LA-CCI 2024

作者： Pastrana, M.A. Oliveira, L.H. Bautista, J. Pinto-Lopera, Jesus Mendoza-Penaloza, Jose Munoz, Daniel M. University of the Amazonia Faculty of Engineering Systems Undergraduate Program Florencia Caquetá Colombia University of Brasilia Mechatronics Graduate Program Department of Mechanical Engineering Brasilia Brazil University of Brasilia Faculty of Gama Electronics Engineering Undergraduate Program Brasilia Brazil

ISBN: (纸本)9798350374575

Artificial neural networks (ANNs) are intricate mathematical models, drawing inspiration from the biological nervous system, and offering intelligence alongside nonparametric capabilities. The efficacy of ANNs heavily relies on their learning process. Heuristic search algorithms have been proposed in literature as reliable options for optimizing neural networks utilizing the Perceptron architecture. This paper presents an suboptimal neural network Perceptron training method employing the Whale Optimization Algorithm for the application of farming watering mobile robots. To achieve this, a fitness function based on system responses such as overshoot, settling Time, and steady-state Error was developed. The sub-optimal Perceptron controller was then implemented using MATLAB, CoppeliaSim software and the EVA robot, resulting in a 66.17% overshoot, a 4.7% steady-state error, and a settling time of 3.05 seconds. Moreover, the sub-optimal Perceptron controller was mapped onto a System on Chip FPGA AMD-Xilinx Zynq 7020, resulting in a hardware resources consumption of 1,870 (3.52%) Lookup table, 2 (0.9%) Digital Signal Processing blocks, 1,019 (0.96%) Flip-Flops and a power consumtion of 0.005 W. Finally, Hardware-in-The-Loop validation was performed using CoppeliaSim, Python, Universal Direct Memory Access, and the EVA robot. The results showed an overshoot of 94.83%, a settling time of 2 seconds, and a steady-state error of 4.5%. © 2024 IEEE.

关键词： MATLAB

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Roles of carbon nanofiber alignment and concentration for the improvement of Z-directional DC electrical conductivity of CNF Z-threaded CFRP laminates manufactured using a radial flow alignment technique 6

Roles of carbon nanofiber alignment and concentration for th...

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6th Annual Composites and Advanced Materials Expo, CAMX 2019

作者： Ranabhat, Bikash Kirmse, Sebastian Hsiao, Kuang-Ting University of South Alabama Department of Mechanical Engineering Shelby Hall 150 Jaguar Drive MobileAL36608 United States Systems Engineering Program

Metal and alloy mesh is primarily used for lightning strike protection (LSP) on the surface of composites. Although this kind of surface mesh technology provides the safety of the passenger, numerous issues persist such as structural damages, galvanic corrosion, structural weight. The development of new electrically conductive carbon fiber reinforced plastics (CFRP) is considered one of the future solutions to LSP. While carbon fibers typically have excellent electrical conductivity, the non-conductive polymer matrix that bonds carbon fibers together to form a CFRP composite adversely reduces the through-thickness directional (i.e., z-directional) electrical conductivity of a CFRP laminate;hence the potential of electrical conductivity of the excellent carbon fiber materials is substantially inhibited. Carbon nanofibers (CNFs), which have a much smaller diameter than carbon fibers and the length long enough to connect more than ten carbon fibers in the transversal direction, can be a candidate to penetrate through the non-conductive resin matrix and connect the individual carbon fibers in the preferred z-direction to form a multiscale conductive fibrous network. The objective of this research is to (1) align the carbon nanofibers in the z-direction with the radial flow alignment technique and use 0.5, 1, 2 wt% concentration of carbon nanofibers to manufacture CNF z-threaded CFRP samples, and (2) measure the through-thickness DC electrical conductivity. Increasing the CNF content in the CNF z-threaded CFRP samples gradually increases the through-thickness DC electrical conductivity. Experimental results showed +257 %, +461 % and +604 % increment in z-direction DC electrical conductivity compared to the control sample when the CNF concentration was increased to 0.5, 1, 2 wt%, respectively. © 2019 by Ever J. Barbero. Published by CAMX - The Composites and Advanced Materials Expo.

关键词： Carbon fiber reinforced plastics

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Hardware Architecture of the EKF Prediction Stage applied to mobile robot localization 6

Hardware Architecture of the EKF Prediction Stage applied to...

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6th IEEE Latin American Symposium on Circuits and systems, LASCAS 2015

作者： Contreras, Luis Cruz, Sérgio Motta, J.M.S.T. Llanos, Carlos H. Graduate Program in Mechatronics Systems Department of Mechanical Engineering University of Brasilia Brasilia D.F.70910-900 Brazil

ISBN: (纸本)9781479983322

This work presents an FPGA-based Hardware Architecture to implement the Prediction Stage of the Extended Kalman Filter (EKF) applied to the localization problem in mobile robotics. The algorithm has been implemented and run on an Altera Cyclone IV FPGA with a Nios II processor, being adapted and applied to the mobile platform Pioneer 3AT (P3AT). The prediction stage was based on a dead-reckoning system model and its architecture was designed for floating-point representation. In this project the complete EKF was also implemented considering an estimation stage hardware architecture previously developed using a Laser Range Finder (LRF) sensor, producing an overall balanced implementation. Finally, it was evaluated the system performance and suitability, measuring FPGA resources consumption and comparing execution time with a software solution. © 2015 IEEE.

关键词： Extended Kalman filters

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Dynamic response modeling of piezoelectric ultrasonic motors

Dynamic response modeling of piezoelectric ultrasonic motors

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2005 ASME International mechanical engineering Congress and Exposition, IMECE 2005

作者： Dabney, James B. Harman, Thomas L. Aswatharanayan, Charanya Ghorbel, Fathi H. Chakkungal, Joseph J. Mary Randolphs-Gips Systems Engineering Program University of Houston - Clear Lake Houston TX Department of Mechanical Engineering Rice University Houston TX

ISBN: (纸本)0791842169

Piezoelectric ultrasonic motors (PUMs) fill a unique niche in mechatronic actuators. The motors are lightweight, simple, and reliable, containing a single moving part that provides the function of motor, transmission, and brake. They are ideal for a variety of robotic applications as well as commercial and medical applications. In order to exploit PUMs fully, computationally efficient models of dynamic response, capturing all important dynamics, are needed. This paper describes the experimental characterization of the dynamic response of a typical commercial PUM (Shinsei USR-30) using an inertial load and evaluation of three classes of dynamic models: second-order predictive (physics-based) models, algebraic (curve fitting) descriptive models, and neural network approximation. Copyright © 2005 by ASME.

关键词： Ultrasonic equipment

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Comparison experiment for pulse repetition interval based length measurement linked to a femtosecond optical frequency comb

Comparison experiment for pulse repetition interval based le...

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20th IMEKO World Congress 2012

作者： Wei, Dong Takamasu, Kiyoshi Matsumoto, Hirokazu Global COE Program - Mechanical Systems Innovation School of Engineering University of Tokyo Tokyo Japan Department of Precision Engineering University of Tokyo Tokyo Japan

ISBN: (纸本)9781627481908

As an alternative to the conventional method, which length measurement is performed as a function of the wavelength of a monochromatic laser source, we proposed the method of measuring arbitrary and absolute length using the pulse repetition interval of a femtosecond optical frequency comb (FOFC - the national standard tool for measuring length in Japan). A helium-neon laser evaluation system was developed for distance determination comparison experiment and its uncertainty estimation was performed in order to validate the proposed method.

关键词： Natural frequencies

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Fales Hot Springs: A case study in renewable augmented net zero energy

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Electricity Journal 2016年第6期29卷 59-70页

作者： Cloud, Andy Sabharwall, Piyush Kerrigan, Meghan Brown, Stephen Renewable Energy and Sustainability Systems Program Penn State University State College PA United States Dept. of Mechanical Aerospace and Nuclear Engineering Rensselaer Polytechnic Institute TroyNY United States

The renewable augmented zero energy (RAZE) structure in Fales Hot Springs, Calif., is near abundant geothermal hot spring, solar, biomass, wind, and run-of-river hydrokinetic natural resources that can be harvested to create a net zero energy facility. This provided an excellent platform from which to systemically assess the technical feasibility, economic efficiency, environmental sustainability, and social benefit as functions of weighted customer requirements. © 2016 Elsevier Inc.

关键词： Hot springs

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