Design of thin-film polyvinylidene fluoride sensor rosettes for isolation of various strain components

2012 ◽  
Vol 23 (10) ◽  
pp. 1119-1130 ◽  
Author(s):  
Lei Ma ◽  
Shreyes N Melkote ◽  
John B Morehouse ◽  
James B Castle ◽  
James W Fonda ◽  
...  
Keyword(s):  
Thin Film ◽  
Strain Gauge ◽  
Polyvinylidene Fluoride ◽  
Dynamic Range ◽  
Deformation Mode ◽  
Strain Gauges ◽  
Metal Foil ◽  
Strain Component ◽  
Promising Alternative ◽  
Fluoride Sensor

Thin-film polyvinylidene fluoride piezoelectric sensors have long been recognized as a promising alternative to traditional metal foil strain gauges in applications where only dynamic or quasistatic signals are of interest. Compared to metal foil strain gauges, polyvinylidene fluoride sensors feature high sensitivity, high dynamic range, and broad frequency bandwidth. However, transverse sensitivity of the polyvinylidene fluoride sensor is higher than that of a metal foil strain gauge, making it more difficult to isolate a particular strain component or a deformation mode when the host structure is under complex loading. In addition, polyvinylidene fluoride films are sensitive to changes in ambient temperature due to the pyroelectric effect. In this article, three temperature-compensated polyvinylidene fluoride sensor rosette designs are proposed for isolating specific strain component(s) and deformation mode(s) of interest. First-principles based models are derived to relate the polyvinylidene fluoride sensor rosette output to the actual elastic strain component of interest. Experimental validation is conducted to verify the proposed models and to compare the performance of the polyvinylidene fluoride sensor rosettes with their metal foil strain gauge counterparts.

Finite Element Modeling of Effect of Adhesive Layer and Carrier Thickness Used for Strain Gauge Mounting

2015 ◽  
Vol 1119 ◽  
pp. 828-832
Author(s):  
K. Vadivuchezhian ◽  
K. Subrahmanya ◽  
N. Chockappan
Keyword(s):  
Finite Element ◽  
Strain Gauge ◽  
Adhesive Layer ◽  
Element Model ◽  
Strain Gauges ◽  
Single Element ◽  
Metal Foil ◽  
Engineering Structures ◽  
Element Analysis ◽  
Typical Strain

Metal foil strain gauges are most widely used for the stress analysis in engineering structures. Typical strain gauge system includes strain sensitive grid, carrier material, and adhesive layer. Strain measurement from the strain gauge is partially affected by carrier and adhesive materials and their thickness. In the present work, a Finite Element Model is developed in order to study the effect of both adhesive layer and carrier thickness on strain measurements while using strain gauges. To understand the behavior of the adhesive material, mechanical characterization is done on bulk adhesive specimen. Finite Element Analysis (FEA) is carried out with different materials namely epoxy and polyurethane. Initially a single element foil loop is considered for the analysis and further this is extended to metal foil strain gauge with nine end-loops. Finally, the strain variation through thickness of adhesive layer, carrier and strain sensitive grid is obtained from FEA. The results thus obtained are compared with analytical results from Basic Strength of Materials approach.

LTCC Substrates for High Performance Strain Gauges

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000175-000180
Author(s):  
Bjoern Brandt ◽  
Marion Gemeinert ◽  
Ralf Koppert ◽  
Jochen Bolte ◽  
Torsten Rabe
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
High Performance ◽  
Coefficient Of Thermal Expansion ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Metal Foil ◽  
Accuracy Class ◽  
Film Sensor ◽  
Load Cells

Recent advances in the development of high gauge factor thin-films for strain gauges prompt the research on advanced substrate materials. A glass ceramic composite has been developed in consideration of a high coefficient of thermal expansion and a low modulus of elasticity for the application as support material for thin-film sensors. Constantan foil strain gauges were fabricated from this material by tape casting, pressure-assisted sintering and subsequent lamination of the metal foil on the planar ceramic substrates. The sensors were mounted on a strain gauge beam arrangement and load curves and creep behavior were evaluated. The accuracy of the assembled load cells correspond to accuracy class C6. That qualifies the load cells for the use in automatic packaging units and confirms the applicability of the LTCC substrates for fabrication of accurate strain gauges. To facilitate the deposition of thin film sensor structures onto the LTCC substrates, the pressure-assisted sintering technology has been refined. By the use of smooth setters instead of release tapes substrates with minimal surface roughness were fabricated. Metallic thin films deposited on these substrates exhibit low surface resistances comparable to thin films on commercial alumina thin-film substrates. The presented advances in material design and manufacturing technology are important to promote the development of high performance thin-film strain gauges.

scholarly journals Novel method to reduce the transverse sensitivity of granular thin film strain gauges by modification of strain transfer

2020 ◽  
Vol 9 (2) ◽  
pp. 219-226
Author(s):  
Maximilian Mathis ◽  
Dennis Vollberg ◽  
Matthäus Langosch ◽  
Dirk Göttel ◽  
Angela Lellig ◽  
...  
Keyword(s):  
Thin Film ◽  
Laser System ◽  
Strain Gauges ◽  
Gauge Factor ◽  
Transverse Strain ◽  
Metal Foil ◽  
Granular Film ◽  
Strain Transfer ◽  
Transverse Sensitivity ◽  
Novel Method

Abstract. Strain gauges based on polyimide carrier foils and piezoresistive granular thin films are highly sensitive to strain. Unlike conventional metal foil, granular film strain gauges also have a pronounced sensitivity to strain acting in the transverse direction. A novel method that allows for the modification of the strain transfer is proposed and proven experimentally. The method is based on the creation of stand-alone polyimide paths, on top of which the piezoresistive thin film is located. In this way, the granular film hardly receives any transverse strain; hence, the transverse sensitivity is drastically reduced. A picosecond laser system can be used for both patterning of the thin film and for controlled ablation of polyimide in order to generate well-defined high path structures. The working principle of the method is demonstrated by simulation, followed by an experimental verification using measurements of the transverse gauge factor. Furthermore, the output signal of force transducers may be increased using granular thin film strain gauges of reduced transverse sensitivity.

Fabrication and Performance Investigation of Karma Alloy Thin Film Strain Gauge

2021 ◽  
Author(s):  
Peng Lei ◽  
Congchun Zhang ◽  
Yawen Pang ◽  
Shenyong Yang ◽  
Meiju Zhang
Keyword(s):  
Thin Film ◽  
Strain Gauge ◽  
Alloy Thin Film ◽  
And Performance

Optimum Strain Gauge Application to Bladed Assemblies

2002 ◽  
Author(s):  
J. Szwedowicz ◽  
S. M. Senn ◽  
R. S. Abhari
Keyword(s):  
Strain Gauge ◽  
Element Model ◽  
Strain Gauges ◽  
Structural Components ◽  
Algorithm Optimization ◽  
Rotating Blades ◽  
Novel Approach ◽  
Present Technique ◽  
Optimization Function ◽  
Rotating Impeller

Optimum placements of the strain gauges assure reliable vibration measurements of structural components such as rotating blades. Within the framework of cyclic vibration theory, a novel approach has been developed for computation of the optimum gauge positions on tuned bladed discs regarding the determined sensitivity, orthogonality, gradient and distance criteria. The utilized genetic algorithm optimization tool allows for an effective numerical search of suitable solutions of the defined optimization function. A rotating impeller disc represented by a cyclic finite element model demonstrates the application of this method. The present technique can be easily applied to other structural components requiring optimal strain gauge instrumentation.

Thin film strain gauges on polymers: main characteristics

1995 ◽  
Vol 46 (1-3) ◽  
pp. 213-217 ◽  
Author(s):  
H. Grange ◽  
C. Maeder ◽  
C. Bieth ◽  
S. Renard ◽  
G. Delapierre
Keyword(s):  
Thin Film ◽  
Strain Gauges
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