On the Comparison Between Displacement Modal Testing and Strain Modal Testing

2015 ◽  
Author(s):  
Emiliano Mucchi ◽  
Giorgio Dalpiaz
Keyword(s):  
High Frequency ◽  
Strain Sensor ◽  
Calibration Procedure ◽  
Strain Sensors ◽  
Modal Testing ◽  
Strain Gauges ◽  
Bonding Quality ◽  
Pros And Cons ◽  
Piezoelectric Strain ◽  
Excitation Force

The conventional modal testing, hereafter referred as Displacement Modal Testing (DMT) is based on measurement of displacement, velocity or acceleration as well as excitation force. An enormous literature regards the DMT, on the contrary, a few papers address modal testing based on strain gauges or strain sensor, hereafter referred as Strain Modal Testing (SMT). The main reason of this scenario is due to practical problems in the use of strain gauges as calibration procedure, ground loop, sensitivity not adequate at high frequency, bonding quality. In this work, a novel piezoelectric strain sensor is used for SMT. It is demonstrated in the present work that this sensor overcomes the practical drawbacks related to the use of strain gauges. Thus, SMT based on piezoelectric strain sensors can be a valid alternative to DMT, usually based on accelerometers. Comparisons between the modal testing results concerning brackets with different constraint conditions using both accelerometers and strain sensors are given in terms of modal parameters, highlighting their pros and cons.

On the comparison between displacement modal testing and strain modal testing

2016 ◽  
Vol 230 (19) ◽  
pp. 3389-3396 ◽  
Author(s):  
Emiliano Mucchi
Keyword(s):  
High Frequency ◽  
Strain Sensor ◽  
Calibration Procedure ◽  
Strain Sensors ◽  
Modal Testing ◽  
Strain Gauges ◽  
Bonding Quality ◽  
Pros And Cons ◽  
Piezoelectric Strain ◽  
Excitation Force

The conventional modal testing (referred to as displacement modal testing (DMT)) is based on measurement of displacement, velocity or acceleration as well as excitation force. Though there exits an enormous literature with regard to DMT, on the contrary, a few papers address modal testing based on strain gauges or strain sensor (referred to as strain modal testing (SMT)). The main reason for this scenario is due to practical problems in the use of strain gauges as calibration procedure, ground loop sensitivity are not adequate at high frequency, bonding quality. In this work, a novel piezoelectric strain sensor is used for SMT. In this study it is demonstrated that this sensor overcomes the practical drawbacks related to the use of strain gauges. Thus, SMT based on piezoelectric strain sensors can be a valid alternative to DMT which is usually based on accelerometers. Comparisons between the modal testing results concerning brackets with different constraint conditions using both accelerometers and strain sensors are given in terms of modal parameters, highlighting their pros and cons.

Efficient Placement of Strain Sensors of Plate Dynamics Based on Some Optimization Criteria

2005 ◽  
Author(s):  
Iva´n Mun˜oz Di´az ◽  
Emiliano Pereira Gonza´lez ◽  
Juan Jose´ Lo´pez Cela ◽  
Vicente Feliu Batlle
Keyword(s):  
Strain State ◽  
Three Dimensional ◽  
Strain Sensor ◽  
Equivalent Strain ◽  
Strain Sensors ◽  
Strain Gauges ◽  
Fiber Grating ◽  
Optimization Criteria ◽  
Modes Of Vibration ◽  
Von Mises

This work presents two criteria for the optimal positioning of strain sensors on a cantilever thin plate, which has bending and torsional modes. The aim is to find an efficient placement of strain sensors in order to maximize the observability of the first N modes of vibration. To this end, we have developed two positioning criteria based on the von Mises equivalent strain, which is a unique representative value of a three-dimensional strain state. The sensors should be placed at points where this equivalent strain presents significant values for the dynamic plate behavior defined by the first N modes. Although these criteria are general and can be applied to any strain sensor, we intend to use fiber grating sensors as strain gauges taking advantage of their inherent characteristics in comparison with other sensors.

Development of Flexible Piezoelectric Strain Sensor Array

2017 ◽  
Vol 137 (12) ◽  
pp. 438-443
Author(s):  
Takahiro Yamashita ◽  
Seiichi Takamatsu ◽  
Hironao Okada ◽  
Toshihiro Itoh ◽  
Takeshi Kobayashi
Keyword(s):  
Sensor Array ◽  
Strain Sensor ◽  
Piezoelectric Strain ◽  
Strain Sensor Array

scholarly journals Development of Highly Sensitive Strain Sensor Using Area-Arrayed Graphene Nanoribbons

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1701
Author(s):  
Ken Suzuki ◽  
Ryohei Nakagawa ◽  
Qinqiang Zhang ◽  
Hideo Miura
Keyword(s):  
Graphene Nanoribbons ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Bending Test ◽  
Gauge Factor ◽  
Four Point Bending ◽  
Current Voltage ◽  
Highly Sensitive ◽  
Current Voltage Relationship

In this study, a basic design of area-arrayed graphene nanoribbon (GNR) strain sensors was proposed to realize the next generation of strain sensors. To fabricate the area-arrayed GNRs, a top-down approach was employed, in which GNRs were cut out from a large graphene sheet using an electron beam lithography technique. GNRs with widths of 400 nm, 300 nm, 200 nm, and 50 nm were fabricated, and their current-voltage characteristics were evaluated. The current values of GNRs with widths of 200 nm and above increased linearly with increasing applied voltage, indicating that these GNRs were metallic conductors and a good ohmic junction was formed between graphene and the electrode. There were two types of GNRs with a width of 50 nm, one with a linear current–voltage relationship and the other with a nonlinear one. We evaluated the strain sensitivity of the 50 nm GNR exhibiting metallic conduction by applying a four-point bending test, and found that the gauge factor of this GNR was about 50. Thus, GNRs with a width of about 50 nm can be used to realize a highly sensitive strain sensor.

scholarly journals Strain Sensor Based on Biological Nanomaterial

2021 ◽  
Vol 6 (1) ◽  
pp. 23
Author(s):  
Levan P. Ichkitidze ◽  
Alexander Yu. Gerasimenko ◽  
Dmitry V. Telyshev ◽  
Eugeny P. Kitsyuk ◽  
Vladimir A. Petukhov ◽  
...  
Keyword(s):  
Screen Printing ◽  
Respiratory Diseases ◽  
Specific Conductivity ◽  
Strain Sensor ◽  
Aqueous Dispersion ◽  
Strain Sensors ◽  
Bending Angle ◽  
Multi Walled Carbon Nanotubes ◽  
Number Of Cycles ◽  
Walled Carbon Nanotubes

We investigated a prototype of a strain sensor based on the layers of a bionanomaterial containing bovine serum albumin (BSA matrix) and multi-walled carbon nanotubes (MWCNT filler). The aqueous dispersion of 25 wt.% BSA/0.3 wt.% MWCNT was applied by screen printing onto flexible polyethylene terephthalate substrates. After drying the layers by laser irradiation (~970 nm), various parameters of the layers were controlled, i.e., resistance R, bending angle θ, number of cycles n, and measurement time. One measurement cycle corresponded to a change within the range θ = ±150°. The layers of the BSA/MWCNT bionanomaterial had dimensions of (15 ÷ 20) mm × (8 ÷ 10) mm × (0.5 ÷ 1. 5) µm. The dependences of resistance R on the bending angle θ were similar for all layers at θ = ±30, and the R(θ) curves represented approximate linear dependences (with an error of ≤ 10%); beyond this range, the dependences became nonlinear. The following quantitative values were obtained for the investigated strain sensor: specific conductivity ~1 ÷ 10 S/m, linear strain sensitivity ~160, and bending sensitivity 1.0 ÷ 1.5%/°. These results are high. The examined layers of the bionanomaterial BSA/MWCNT as a strain sensor are of particular interest for medical practice. In particular, strain sensors can be implemented by applying a water dispersion of nanomaterials to human skin using a 3D printer for monitoring movements (arms and blinking) and the detection of signs of pathology (dysphagia, respiratory diseases, angina, etc.).

scholarly journals Parasitic Loop Inductances Reduction in the PCB Layout in GaN-Based Power Converters Using S-Parameters and EM Simulations

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1495
Author(s):  
Loris Pace ◽  
Nadir Idir ◽  
Thierry Duquesne ◽  
Jean-Claude De Jaeger
Keyword(s):  
High Frequency ◽  
Printed Circuit Board ◽  
Power Converters ◽  
Calibration Procedure ◽  
Circuit Board ◽  
Design System ◽  
Switching Speed ◽  
Parasitic Inductance ◽  
Frequency Converters ◽  
S Parameters

Due to the high switching speed of Gallium Nitride (GaN) transistors, parasitic inductances have significant impacts on power losses and electromagnetic interferences (EMI) in GaN-based power converters. Thus, the proper design of high-frequency converters in a simulation tool requires accurate electromagnetic (EM) modeling of the commutation loops. This work proposes an EM modeling of the parasitic inductance of a GaN-based commutation cell on a printed circuit board (PCB) using Advanced Design System (ADS®) software. Two different PCB designs of the commutation loop, lateral (single-sided) and vertical (double-sided) are characterized in terms of parasitic inductance contribution. An experimental approach based on S-parameters, the Cold FET technique and a specific calibration procedure is developed to obtain reference values for comparison with the proposed models. First, lateral and vertical PCB loop inductances are extracted. Then, the whole commutation loop inductances including the packaging of the GaN transistors are determined by developing an EM model of the device’s internal parasitic. The switching waveforms of the GaN transistors in a 1 MHz DC/DC converter are given for the different commutation loop designs. Finally, a discussion is proposed on the presented results and the development of advanced tools for high-frequency GaN-based power electronics design.

scholarly journals Giant gauge factor of Van der Waals material based strain sensors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjie Yan ◽  
Huei-Ru Fuh ◽  
Yanhui Lv ◽  
Ke-Qiu Chen ◽  
Tsung-Yin Tsai ◽  
...  
Keyword(s):  
Carrier Mobility ◽  
Large Range ◽  
Van Der Waals ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Proof Of Concept ◽  
High Flexibility ◽  
Small Deformations

AbstractThere is an emergent demand for high-flexibility, high-sensitivity and low-power strain gauges capable of sensing small deformations and vibrations in extreme conditions. Enhancing the gauge factor remains one of the greatest challenges for strain sensors. This is typically limited to below 300 and set when the sensor is fabricated. We report a strategy to tune and enhance the gauge factor of strain sensors based on Van der Waals materials by tuning the carrier mobility and concentration through an interplay of piezoelectric and photoelectric effects. For a SnS2 sensor we report a gauge factor up to 3933, and the ability to tune it over a large range, from 23 to 3933. Results from SnS2, GaSe, GeSe, monolayer WSe2, and monolayer MoSe2 sensors suggest that this is a universal phenomenon for Van der Waals semiconductors. We also provide proof of concept demonstrations by detecting vibrations caused by sound and capturing body movements.

scholarly journals A Novel Textile Stitch-Based Strain Sensor for Wearable End Users

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1469 ◽  
Author(s):  
Orathai Tangsirinaruenart ◽  
George Stylios
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistance ◽  
Body Movement ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Heart Monitoring ◽  
Textile Sensors ◽  
Good Repeatability ◽  
The Ideal

This research presents an investigation of novel textile-based strain sensors and evaluates their performance. The electrical resistance and mechanical properties of seven different textile sensors were measured. The sensors are made up of a conductive thread, composed of silver plated nylon 117/17 2-ply, 33 tex and 234/34 4-ply, 92 tex and formed in different stitch structures (304, 406, 506, 605), and sewn directly onto a knit fabric substrate (4.44 tex/2 ply, with 2.22, 4.44 and 7.78 tex spandex and 7.78 tex/2 ply, with 2.22 and 4.44 tex spandex). Analysis of the effects of elongation with respect to resistance indicated the ideal configuration for electrical properties, especially electrical sensitivity and repeatability. The optimum linear working range of the sensor with minimal hysteresis was found, and the sensor’s gauge factor indicated that the sensitivity of the sensor varied significantly with repeating cycles. The electrical resistance of the various stitch structures changed significantly, while the amount of drift remained negligible. Stitch 304 2-ply was found to be the most suitable for strain movement. This sensor has a wide working range, well past 50%, and linearity (R2 is 0.984), low hysteresis (6.25% ΔR), good gauge factor (1.61), and baseline resistance (125 Ω), as well as good repeatability (drift in R2 is −0.0073). The stitch-based sensor developed in this research is expected to find applications in garments as wearables for physiological wellbeing monitoring such as body movement, heart monitoring, and limb articulation measurement.

scholarly journals Structural Reinforcement Effect of a Flexible Strain Sensor Integrated with Pneumatic Balloon Actuators for Soft Microrobot Fingers

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 395
Author(s):  
Satoshi Konishi ◽  
Fuminari Mori ◽  
Ayano Shimizu ◽  
Akiya Hirata
Keyword(s):  
Liquid Metal ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Original Performance ◽  
Sensors And Actuators ◽  
Parylene C ◽  
Structural Reinforcement ◽  
Effective Combination ◽  
Metal Strain ◽  
Flexible Strain Sensor

Motion capture of a robot and tactile sensing for a robot require sensors. Strain sensors are used to detect bending deformation of the robot finger and to sense the force from an object. It is important to introduce sensors in effective combination with actuators without affecting the original performance of the robot. We are interested in the improvement of flexible strain sensors integrated into soft microrobot fingers using a pneumatic balloon actuator (PBA). A strain sensor using a microchannel filled with liquid metal was developed for soft PBAs by considering the compatibility of sensors and actuators. Inflatable deformation generated by PBAs, however, was found to affect sensor characteristics. This paper presents structural reinforcement of a liquid metal-based sensor to solve this problem. Parylene C film was deposited into a microchannel to reinforce its structure against the inflatable deformation caused by a PBA. Parylene C deposition into a microchannel suppressed the interference of inflatable deformation. The proposed method enables the effective combination of soft PBAs and a flexible liquid metal strain sensor for use in microrobot fingers.

Research on the Performance of Strain Sensors Applied to Bridges

2014 ◽  
Vol 875-877 ◽  
pp. 680-684
Author(s):  
Zhi Liu ◽  
Jing Liu ◽  
Shu Ri Cai
Keyword(s):  
Health Monitoring ◽  
Performance Test ◽  
Strain Sensor ◽  
Safety Monitoring ◽  
Strain Sensors ◽  
Great Role ◽  
Temperature Drift ◽  
Short Life ◽  
Test Analysis ◽  
Health Monitoring System

Strengthening safety monitoring of bridges during service time and improving the capability of emergency support have become the priority of the development of China’s present transportation system. Strain sensors play a great role in bridge detection and health monitoring system. In order to overcome disadvantages of traditional resistance strain sensors, such as big temperature drift, short life and inadaptability in the environment of low temperature and humidity, new arch strain sensors have been developed. This paper mainly discusses the structural and material characteristics of this sensor, as well as the performance test analysis of this strain sensor.

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