Self-Powered Non-Contact Triboelectric Rotation Sensor with Interdigitated Film

Rotation detection is widely applied in industries. The current commonly used rotation detection system adopts a split structure, which requires stringent installation requirements and is difficult to miniaturize. This paper proposes a single-piece self-powered non-contact sensor with an interdigital sensitive layer to detect the rotation of objects. The electric field generated between a polyurethane (PU) film and a polytetrafluoroethylene (PTFE) film is utilized for perceiving the rotation. The surface of the PU film is subjected to wet etching with sulfuric acid to increase the surface area and charge density. Through finite element analysis and experimental testing, the effects of the areas of the sensitive films as well as the horizontal and vertical distances between them on the output voltage are analyzed. Tests are performed on adjustable-speed motors, human arms, and robotic arms. The results show that the sensor can detect the speed, the transient process of rotation, and the swing angle. The proposed rotation sensor has broad application prospects in the fields of mechanical automation, robotics, and Internet of Things (IoT).

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Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation

Materials ◽

10.3390/ma14020314 ◽

2021 ◽

Vol 14 (2) ◽

pp. 314

Author(s):

Miroslav Pástor ◽

Martin Hagara ◽

Ivan Virgala ◽

Adam Kaľavský ◽

Alžbeta Sapietová ◽

...

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Experimental Testing ◽

Digital Processing ◽

Image Correlation ◽

Optical Systems ◽

Hole Drilling ◽

Element Analysis ◽

Thin Specimen ◽

Comparison Of The Results

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

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Sustainable Security for the Internet of Things Using Artificial Intelligence Architectures

ACM Transactions on Internet Technology ◽

10.1145/3448614 ◽

2021 ◽

Vol 21 (3) ◽

pp. 1-22

Author(s):

Celestine Iwendi ◽

Saif Ur Rehman ◽

Abdul Rehman Javed ◽

Suleman Khan ◽

Gautam Srivastava

Keyword(s):

Internet Of Things ◽

Detection System ◽

Experimental Testing ◽

Cyber Attacks ◽

Internet Technology ◽

The Internet ◽

Business Operations ◽

Private Data ◽

The Internet Of Things ◽

Better Than

In this digital age, human dependency on technology in various fields has been increasing tremendously. Torrential amounts of different electronic products are being manufactured daily for everyday use. With this advancement in the world of Internet technology, cybersecurity of software and hardware systems are now prerequisites for major business’ operations. Every technology on the market has multiple vulnerabilities that are exploited by hackers and cyber-criminals daily to manipulate data sometimes for malicious purposes. In any system, the Intrusion Detection System (IDS) is a fundamental component for ensuring the security of devices from digital attacks. Recognition of new developing digital threats is getting harder for existing IDS. Furthermore, advanced frameworks are required for IDS to function both efficiently and effectively. The commonly observed cyber-attacks in the business domain include minor attacks used for stealing private data. This article presents a deep learning methodology for detecting cyber-attacks on the Internet of Things using a Long Short Term Networks classifier. Our extensive experimental testing show an Accuracy of 99.09%, F1-score of 99.46%, and Recall of 99.51%, respectively. A detailed metric representing our results in tabular form was used to compare how our model was better than other state-of-the-art models in detecting cyber-attacks with proficiency.

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On-Site Experimental Testing to Study the Vibration of Composite Floors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.601.231 ◽

2014 ◽

Vol 601 ◽

pp. 231-234

Author(s):

Cristian Lucian Ghindea ◽

Dan Cretu ◽

Monica Popescu ◽

Radu Cruciat ◽

Elena Tulei

Keyword(s):

Dynamic Characteristics ◽

Experimental Testing ◽

Concrete Slab ◽

Human Perception ◽

Experimental Tests ◽

International Standards ◽

Structural Element ◽

Element Analysis ◽

Floor Slabs ◽

Composite Floors

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.

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DESIGN AND ANALYSIS OF AN INTEGRATED THREE- BAY THERMOPLASTIC COMPOSITE WINGBOX

10.12783/asc36/35766 ◽

2021 ◽

Author(s):

VINCENZO OLIVERI ◽

GIOVANNI ZUCCO ◽

MOHAMMAD ROUHI ◽

ENZO COSENTINO ◽

RONAN O’HIGGINS ◽

...

Keyword(s):

Variable Stiffness ◽

Thermoplastic Composite ◽

High Fidelity ◽

Material System ◽

Load Carrying Capacity ◽

Element Analysis ◽

Single Piece ◽

Load Carrying ◽

Post Buckling ◽

Composite Material System

The design of a multi-part aerospace structural component, such as a wingbox, is a challenging process because of the complexity arising from assembly and integration, and their associated limitations and considerations. In this study, a design process of a stiffeners-integrated variable stiffness three-bay wingbox is presented. The wingbox has been designed for a prescribed buckling and post-buckling performance (a prescribed real testing scenario) and made from thermoplastic composite material system (Carbon-PEEK) with the total length of three meters. The stiffeners and spars are integrated into the top and bottom panels of the wingbox resulting a single-piece blended structure with no fasteners or joints. The bottom skin also has an elliptical cut-out for access purposes. The composite tows are steered around this cutout for strain concentration reduction purposes. The fiber/tow steering in the top skin bays (compression side) has also been considered for improved compression-induced buckling load carrying capacity. The proposed design has been virtually verified via high fidelity finite element analysis.

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Fatigue crack detection in pipes with multiple mode nonlinear guided waves

Structural Health Monitoring ◽

10.1177/1475921718791134 ◽

2018 ◽

Vol 18 (1) ◽

pp. 180-192 ◽

Cited By ~ 13

Author(s):

Ruiqi Guan ◽

Ye Lu ◽

Kai Wang ◽

Zhongqing Su

Keyword(s):

Fatigue Crack ◽

Crack Detection ◽

Guided Waves ◽

Second Harmonic ◽

Experimental Testing ◽

Harmonic Wave ◽

Guided Wave ◽

Element Analysis ◽

Fatigue Crack Detection ◽

Wave Modes

This study elaborates fundamental differences in fatigue crack detection using nonlinear guided waves between plate and pipe structures and provides an effective approach for analysing nonlinearity in pipe structures. For this purpose, guided wave propagation and interaction with microcrack in a pipe structure, which introduced a contact acoustic nonlinearity, was analysed through a finite element analysis in which the material nonlinearity was also included. To validate the simulation results, experimental testing was performed using piezoelectric transducers to generate guided waves in a specimen with a fatigue crack. Both methods revealed that the second harmonic wave generated by the breathing behaviour of the microcrack in a pipe had multiple wave modes, unlike the plate scenario using nonlinear guided waves. Therefore, a proper index which considered all the generated wave modes due to the microcrack was developed to quantify the nonlinearity, facilitating the identification of microscale damage and further assessment of the severity of the damage in pipe structures.

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Self-Powered Multifunctional Instrumented Knee Implant

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2018-8078 ◽

2018 ◽

Author(s):

Mohsen Safaei ◽

Steven R. Anton

Keyword(s):

Finite Element ◽

Energy Harvesting ◽

Knee Replacement ◽

Center Of Pressure ◽

Experimental Testing ◽

Sensory System ◽

Implant Design ◽

Total Force ◽

Self Powered

Computational modeling, instrumented linkages, optical technologies, MRI, and radiographic techniques have been widely used to study knee motion after total knee replacement (TKR) surgery. Information provided by these methods has helped designers to develop implants with better clinical performance and surgeons to obtain an improved understanding of the stability and mobility of the joint. Correspondingly, overall patient satisfaction with respect to the reduction in pain and recovery of normal functioning of the joint has been improving. However, about 20% of patients are still not fully satisfied with their surgical outcomes. The main obstacle in the current state-of-the-art is that a comprehensive post-operative understanding of knee balance is still unavailable, mostly due to a lack of in vivo data collected from the joint after surgery. This work presents an attempt to develop a self-powered instrumented knee implant for in vivo data acquisition. The knee sensory system in this study utilizes several embedded piezoelectric transducers in the tibial bearing of the knee replacement in order to provide sensing and energy harvesting capabilities. Through a series of analytical modeling, finite element simulation, and experimental testing, the performance of the suggested system is evaluated and a dimensionally optimized design of an instrumented TKR is achieved. More specifically, a comprehensive platform is established in order to combine the knowledge of embedded piezoelectric sensors and energy harvesters, musculoskeletal modeling of the knee joint, multiphysics finite element modeling, additive manufacturing techniques, image processing, and experimental knee loading simulation in order to achieve the experimentally validated and optimized instrumented knee implant design. The cumulative work presented in this article encompasses three main studies performed on the sensing performance of the proposed design: first, preliminary parametric studies of the effect of local dimensional and material parameters on the electromechanical behavior of the embedded sensory system; second, investigation of the ability to sense total force and center of pressure location; and third, evaluation of an enhanced system with the ability to sense compartmental forces and contact locations. Additionally, the energy harvesting capacity of the system is investigated to ensure the achievement of a fully self-powered sensory system. Results obtained from the experimental analysis of the system demonstrate the successful sensing and energy harvesting performance of the designs achieved in this study.

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Design of an Air-Cooled Radial Turbine: Part 1 — Computational Modelling

Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines ◽

10.1115/gt2018-76378 ◽

2018 ◽

Cited By ~ 2

Author(s):

Yang Zhang ◽

Tomasz Duda ◽

James A. Scobie ◽

Carl M. Sangan ◽

Colin D. Copeland ◽

...

Keyword(s):

Numerical Simulation ◽

Experimental Testing ◽

Temperature Drop ◽

Computational Modelling ◽

Operating Conditions ◽

Inlet Temperature ◽

Topology Optimisation ◽

Internal Cooling ◽

Element Analysis ◽

Radial Turbine

This paper is part of a two-part publication that aims to design, simulate and test an internally air cooled radial turbine. To achieve this, the additive manufacturing process, Selective Laser Melting (SLM), was utilized to allow internal cooling passages within the blades and hub. This is, to the authors’ knowledge, the first publication in the open literature to demonstrate an SLM manufactured, cooled concept applied to a small radial turbine. In this paper, the internally cooled radial turbine was investigated using a Conjugate Heat Transfer (CHT) numerical simulation. Topology Optimisation was also implemented to understand the areas of the wheel that could be used safely for cooling. In addition, the aerodynamic loss and efficiency of the design was compared to a baseline non-cooled wheel. The experimental work is detailed in Part 2 of this two-part publication. Given that the aim was to test the rotor under representative operating conditions, the material properties were provided by the SLM technology collaborator. The boundary conditions for the numerical simulation were derived from the experimental testing where the inlet temperature was set to 1023 K. A polyhedral unstructured mesh made the meshing of internal coolant plenums including the detailed supporting structures possible. The simulation demonstrated that the highest temperature at the blade leading edge was 117 K lower than the uncooled turbine. The coolant mass flow required by turbine was 2.5% of the mainstream flow to achieve this temperature drop. The inertia of the turbine was also reduced by 20% due to the removal of mass required for the internal coolant plenums. The fluid fields in both the coolant channels and downstream of the cooled rotor were analyzed to determine the aerodynamic influence on the temperature distribution. Furthermore, the solid stress distribution inside the rotor was analyzed using Finite Element Analysis (FEA) coupled with the CFD results.

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Linac Beam Loss Detection System Using Self-Powered Detectors

IEEE Transactions on Nuclear Science ◽

10.1109/tns.1969.4325088 ◽

1969 ◽

Vol 16 (1) ◽

pp. 103-106 ◽

Cited By ~ 2

Author(s):

J. S. Hewitt ◽

E. W. Horrigan

Keyword(s):

Detection System ◽

Beam Loss ◽

Self Powered

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Computational Process Simulation and Energy Parameter Analysis From Mechanical Deformation of Aerospace Alunimum Alloys

Recent Advances in Solids and Structures ◽

10.1115/imece2002-39290 ◽

2002 ◽

Author(s):

James M. Fragomeni ◽

Giridhar Venugopal

Keyword(s):

Yield Strength ◽

Experimental Testing ◽

True Strain ◽

Energy Parameter ◽

True Stress ◽

Parameter Analysis ◽

Dissipated Energy ◽

Strain Hardening Exponent ◽

Element Analysis ◽

Buckling Strength

Many systems that work on the processing of energy can be modeled in terms of that energy. The energy that is given to the system may be stored or dissipated in the form of heat. It was proposed to extend this concept to attainment of critical level of stored energy and/or dissipated energy for occurrence of buckling of a metal column under compressive loading. The fact that Energy Factor Parameter (E.F.P.) computed from the experimental true stress-true strain values, suddenly decreased and approached value close to zero indicated either buckling and/or softening, but deviated with the E.F.P. computed from the theoretical true stress and true strain values. The 7050-T7451 (Al-Zn-Mg-Cu-Zr) and Al-Li-Cu aluminum alloys in longitudinal and transverse grain orientations were compression tested for mechanical properties of yield strength, buckling strength, strength coefficient, strain hardening exponent. Correlation between ratio of buckling strength and yield strength with aging time for preaged ASTM compression specimens was established. The compression deformation of aluminum alloy 7050 was modeled using finite element analysis, with the experimental testing parameters and the database in the software package.

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