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.

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.

scholarly journals Wearable piezoresistive strain sensor based on graphene-coated three-dimensional micro-porous PDMS sponge

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Young Jung ◽  
Kyungkuk Jung ◽  
Byunggeon Park ◽  
Jaehyuk Choi ◽  
Donghwan Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Three Dimensional ◽  
Strain Sensor ◽  
Cost Effective ◽  
Dip Coating ◽  
Strain Sensors ◽  
Effective Manner ◽  
Coating Method ◽  
Dip Coating Method ◽  
Sensing Performance

Abstract We present a highly elastic and wearable piezoresistive strain sensor based on three-dimensional, micro-porous graphene-coated polydimethylsiloxane (PDMS) sponge suitable for being attached on human skin. The proposed strain sensors are simply fabricated by a sugar templating process and dip coating method based graphene ink in a facile and cost effective manner. The fabricated graphene-coated PDMS sponge shows highly stable mechanical properties in various tensile stress–strain test. A graphene thin film coated onto the backbone of PDMS sponges is used as the sensing materials of piezoresisitve strain sensors. The changes in resistance of the devices are highly stable, repeatable, and reversible when various strain is applied. Furthermore, the strain sensors show excellent sensing performance under different strain rate and mechanically robustness enough to be worked stably under repeated loads without any degradation.

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.

The Comparison and Analysis of Fiber Grating Strain Sensor and Resistance Strain Slice for Transmission Tower Vibration Monitoring

2014 ◽  
Vol 533 ◽  
pp. 211-213
Author(s):  
Jin Feng Geng ◽  
Dong Fang Ma ◽  
Hong Sheng Cai ◽  
Wen Tao Wu ◽  
Jun Wei Dong ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Strain Sensor ◽  
Strain Sensors ◽  
Resistance Strain ◽  
Vibration Monitoring ◽  
Bragg Grating ◽  
Fiber Grating ◽  
Transmission Tower ◽  
Existing Problems ◽  
Tower Vibration

Contrast advantages and existing problems of resistance strain slice and fiber grating strain sensor for tower vibration strain monitoring, compare the structure of the two, and do the on-site installation and experiments, analyze the monitoring data. It can make a conclusion that the properties of fiber bragg grating strain sensors are basic consistent with resistance strain slice. And fiber bragg grating strain sensors can be used for transmission tower vibration monitoring .

scholarly journals Highly sensitive strain sensors based on hollow packaged silver nanoparticle-decorated three-dimensional graphene foams for wearable electronics

RSC Advances ◽  
2019 ◽  
Vol 9 (68) ◽  
pp. 39958-39964
Author(s):  
Xinxiu Wu ◽  
Fangfang Niu ◽  
Ao Zhong ◽  
Fei Han ◽  
Yun Chen ◽  
...  
Keyword(s):  
Silver Nanoparticle ◽  
Three Dimensional ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Strain Sensors ◽  
Sensitive Strain ◽  
Wearable Electronics ◽  
Sensor Applications ◽  
Highly Sensitive ◽  
Graphene Foams

Silver nanoparticle-decorated three-dimensional graphene foams were prepared and packaged with half-cured PMDS films, forming a special “hollow packaged” structure that exhibited high sensitivity for wearable strain sensor applications.

Three-Dimensional Graphene-Based Composite for Elastic Strain Sensor Applications

MRS Advances ◽  
2016 ◽  
Vol 1 (34) ◽  
pp. 2415-2420 ◽  
Author(s):  
Jinhui Li ◽  
Guoping Zhang ◽  
Rong Sun ◽  
C. P. Wong
Keyword(s):  
Flexible Electronics ◽  
Performance Monitoring ◽  
Three Dimensional ◽  
Strain Sensor ◽  
High Sensitivity ◽  
Human Motion ◽  
Strain Sensors ◽  
Sensor Applications ◽  
Human Motion Detection ◽  
Highly Stretchable

ABSTRACTFlexible electronics has emerged as a very promising field, in particular,wearable, bendable, and stretchable strain sensors with high sensitivity which could be used for human motion detection, sports performance monitoring, etc. In this paper, a highly stretchable and sensitive strain sensor composed of reduced graphene oxide foam and elastomer composite is fabricated by assembly and followed by a polymer immersing process. The strain sensor has demonstrated high stretchability and sensitivity. Furthermore, the device was employed for gauging muscle-induced strain which results in high sensitivity and reproducibility. The developed strain sensors showed great application potential in fields of biomechanical systems.

Comparison of Stress-Strain States of Rail-Wheel Pair Made of Steel and MoNiCa

2021 ◽  
Vol 320 ◽  
pp. 14-19
Author(s):  
Sergei Sherbakov ◽  
Aliaksandr Bahdanovich ◽  
Aleh Nasan ◽  
Daria Podgayskaya ◽  
Liudmila Shemet ◽  
...  
Keyword(s):  
Strain State ◽  
Rail Steel ◽  
Three Dimensional ◽  
High Strength ◽  
Bottom Surface ◽  
Stress Strain ◽  
Wheel Pair ◽  
Stress Strain State ◽  
Freight Car ◽  
Von Mises

Contact interaction in a wheel-rail pair and its corresponding stress-strain state for various combinations of materials of this pair and the weights of passenger and freight cars were considered. The materials under study were steel and high-strength cast iron based structural material MoNiCa with strength and wear-fatigue characteristics close to steel ones.The load on each wheel was: 53.9 and 294.3 kN for an empty and loaded freight car, 146.8 kN and 230.5 kN for an empty and loaded passenger car. The bottom surface of the rail was rigidly fixed.Young's modules were adopted as follows: 200 GPa for steel and 165 for MoNiCa. The results of finite element calculations of the three-dimensional stress-strain state showed that the largest von Mises stresses of 613.08 MPa occur in the wheel (steel)-rail (steel) pair of the loaded freight car. For all types of loading, the lowest stresses (15.8 % – 16.7 % less than in the steel-steel pair) are observed in the wheel (MoNiCa)-rail (MoNiCa) pair. This indicates the appropriateness of using MoNiCa for the manufacturing elements of the wheel-rail system.

scholarly journals Rapid Prototyping Human Interfaces Using Stretchable Strain Sensor

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Tokiya Yamaji ◽  
Hiroyuki Nakamoto ◽  
Hideo Ootaka ◽  
Ichiro Hirata ◽  
Futoshi Kobayashi
Keyword(s):  
Rapid Prototyping ◽  
Electronic Devices ◽  
Three Dimensional ◽  
Strain Sensor ◽  
Modern Society ◽  
High Accuracy ◽  
Strain Sensors ◽  
Individual User ◽  
Universal Device ◽  
The Individual

In the modern society with a variety of information electronic devices, human interfaces increase their importance in a boundary of a human and a device. In general, the human is required to get used to the device. Even if the device is designed as a universal device or a high-usability device, the device is not suitable for all users. The usability of the device depends on the individual user. Therefore, personalized and customized human interfaces are effective for the user. To create customized interfaces, we propose rapid prototyping human interfaces using stretchable strain sensors. The human interfaces comprise parts formed by a three-dimensional printer and the four strain sensors. The three-dimensional printer easily makes customized human interfaces. The outputs of the interface are calculated based on the sensor’s lengths. Experiments evaluate three human interfaces: a sheet-shaped interface, a sliding lever interface, and a tilting lever interface. We confirm that the three human interfaces obtain input operations with a high accuracy.

Effects of occlusal scheme on All-on-Four abutments, screws and prostheses: A three-dimensional finite element study

2020 ◽  
Author(s):  
Nurullah Türker ◽  
Hümeyra Tercanlı Alkış ◽  
Steven J Sadowsky ◽  
Ulviye Şebnem Büyükkaplan
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Good Prognosis ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Group Function ◽  
Occlusal Contact ◽  
Maximum Deformation ◽  
Contact Points ◽  
Von Mises

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, due to the potential impact of occlusal loads on implant prosthetic components. The aim of the present three-dimensional (3D) finite element analysis (FEA) study was to investigate the stresses on abutments, screws and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. Three-dimensional models of the maxilla, mandible, implants, implant substructures and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO) and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments and prostheses in the All-on-Four concept.

MODELING OF THE STRESS-STRAIN STATE OF A TRANSPORT TUNNEL UNDER LOAD AS A MEASURE TO REDUCE OPERATIONAL RISKS TO TRANSPORTATION FACILITIES

2020 ◽  
Vol 3 (8) ◽  
pp. 28-34
Author(s):  
N. V. IVANITSKAYA ◽  
◽  
A. K. BAYBULOV ◽  
M. V. SAFRONCHUK ◽  
◽  
...  
Keyword(s):  
Strain State ◽  
Moving Load ◽  
Element Model ◽  
Transport Infrastructure ◽  
Design Stage ◽  
Surface Load ◽  
Stress Strain ◽  
Stress Strain State ◽  
Operational Risks ◽  
Von Mises

In many countries economic policy has been paying increasing attention to the modernization and development of transport infrastructure as a measure of macroeconomic stimulation. Tunnels as an important component of transport infrastructure save a lot of logistical costs. It stimulates increasing freight and passenger traffic as well as the risks of the consequences of unforeseen overloads. The objective of the paper is to suggest the way to reduce operational risks of unforeseen moving load by modeling of the stress-strain state of a transport tunnel under growing load for different conditions and geophysical parameters. The article presents the results of a study of the stress-strain state (SSS) of a transport tunnel exposed to a mobile surface load. Numerical experiments carried out in the ANSYS software package made it possible to obtain diagrams showing the distribution of equivalent stresses (von Mises – stresses) according to the finite element model of the tunnel. The research results give grounds to assert that from external factors the stress state of the tunnel is mainly influenced by the distance to the moving load. The results obtained make it possible to predict in advance the parameters of the stress-strain state in the near-contour area of the tunnel and use the results in the subsequent design of underground facilities, as well as to increase their reliability and operational safety. This investigation gives an opportunity not only to reduce operational risks at the design stage, but to choose an optimal balance between investigation costs and benefits of safety usage period prolongation.

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