scholarly journals Monitoring the Structural Health of Glass Fibre-Reinforced Hybrid Laminates Using Novel Piezoceramic Film

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5428 ◽  
Author(s):  
René Schmidt ◽  
Alexander Graf ◽  
Ricardo Decker ◽  
Michael Heinrich ◽  
Verena Kräusel ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Failure Modes ◽  
Testing Machine ◽  
Structural Health ◽  
Fibre Breakage ◽  
Hybrid Laminates ◽  
Glass Fibre Reinforced ◽  
Sensor Signals ◽  
Fibre Metal ◽  
New Generation

This work investigates a new generation structural health monitoring (SHM) system for fibre metal laminates (FML) based on an embedded thermoplastic film with compounded piezoceramics, termed piezo-active fibre metal laminate (PFML). The PFML is manufactured using near-series processes and its potential as a passive SHM system is being investigated. A commercial Polyvinylidene fluoride (PVDF) sensor film is used for comparative evaluation of the sensor signals. Furthermore, thermoset and thermoplastic-based FML are equipped with the sensor films and evaluated. For this purpose, static and dynamic three-point bending tests are carried out and the data are recorded. The data obtained from the sensors and the testing machine are compared with the type and time of damage by means of intelligent signal processing. By using a smart sensor system, further investigations are planned which the differentiation between various failure modes, e.g., delamination or fibre breakage.

The Effects of Hydrothermal Ageing on the Crushing Behavior of Glass/Epoxy Composite Pipes

2015 ◽  
Vol 819 ◽  
pp. 411-416
Author(s):  
S.N. Fitriah ◽  
M.S. Abdul Majid ◽  
R. Daud ◽  
M. Afendi ◽  
Z.S. Nazirah
Keyword(s):  
Composite Laminates ◽  
Testing Machine ◽  
Hydrothermal Condition ◽  
Compression Tests ◽  
Universal Testing ◽  
Failure Region ◽  
The Matrix ◽  
Glass Fibre Reinforced ◽  
Crushing Behavior ◽  
Composite Pipes

The paper discusses the crushing behavior of glass fibre reinforced epoxy (GRE) pipes under hydrothermal ageing condition. This study determines the behavior of the GRE pipes when subjected to different ageing periods and temperatures. Hydrothermal ageing has been found to cause degradation between resin and fibre interface thus causing the reduction in the strength of composite laminates. The pipes were subjected to hydrothermal condition to simulate and precipitate ageing by immersing the pipe samples in water at 80°C for 250, 500, and 1000 hours. Compression tests were carried out using Universal Testing Machine (UTM) for virgin condition and aged samples in accordance with ASTM D695 standard. The maximum force at the initial failure region is observed for each of the conditioned pipes. The results show that the strength of the matrix systems was considerably degraded due to the plasticization of the matrix system.

Thin-Film PVDF Sensor Based Monitoring of Cutting Forces in Peripheral End Milling

2012 ◽  
Author(s):  
Lei Ma ◽  
Shreyes N. Melkote ◽  
John B. Morehouse ◽  
James B. Castle ◽  
James W. Fonda ◽  
...  
Keyword(s):  
Thin Film ◽  
Polyvinylidene Fluoride ◽  
End Milling ◽  
Beam Theory ◽  
Dynamic Strain ◽  
Data Logging ◽  
Sensor Material ◽  
Sensor Module ◽  
Sensor Signals

A sensor module that integrates a thin film Polyvinylidene Fluoride (PVDF) piezoelectric strain sensor and an in situ data logging platform has been designed and implemented for monitoring of feed and transverse forces in the peripheral end milling process. The module, which is mounted on the tool shank, measures the dynamic strain(s) produced in the tool and logs the data into an on-board card for later retrieval. The close proximity between the signal source and the PVDF sensor(s) minimizes the attenuation and distortion of the signal along the transmitting path and provides high-fidelity signals. It also facilitates the employment of a first principles model based on Euler-Bernoulli beam theory and the constitutive equations of the piezoelectric sensor material to relate the in situ measured PVDF sensor signals to the feed and transverse forces acting on the tool. The PVDF sensor signals are found to compare well with the force signals measured by a platform type piezoelectric force dynamometer in peripheral end milling experiments.

scholarly journals Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures

2016 ◽  
Vol 6 (1) ◽  
pp. 19-23
Author(s):  
Amol Mhatre ◽  
VK Ravindranath ◽  
Sachin Doshi ◽  
Girish Karandikar ◽  
PS Vivek
Keyword(s):  
Testing Machine ◽  
Frictional Resistance ◽  
Minimal Amount ◽  
New Delhi ◽  
Low Friction ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
New Generation

ABSTRACT Aim The aim of this in vitro study was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTM and AlastiKTM Easy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures. Materials and Methods Sixty ligature samples divided into four groups were used for the study. Group A: QuiK-StiK™ (3M Unitek, Monrovia, CA, USA), Group B: AlastiK™ Easy-to-Tie (3M Unitek, Monrovia, CA, USA), Group C: Slide™ (Leone, Firenze, Italy), and Group D: SS ligatures 0.010” (Libral Traders, New Delhi, India). Universal Testing Machine, Instron was used for measuring FR at the bracket-wire interface. Results There was statistically significant difference in FR among all the four groups of ligatures tested (p < 0.001). Slide ligatures produced the least amount of FR followed by SS ligatures, Easy-to-Tie, and QuiK-StiK in the increasing order of the FR values registered. Conclusion SlideTM ligatures may represent a valid alternative to passive self-ligating brackets when minimal amount of friction is desired. Angulation introduced into the elastomeric ligatures reduces the friction in comparison to conventional elastomeric ligatures. How to cite this article Vivek PS, Ravindranath VK, Karandikar G, Doshi S, Mhatre A, Sonawane M. Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures. J Contemp Dent 2016;6(1):19-23.

scholarly journals Comparative Evaluation of Fracture Resistance and Mode of Failure of Zirconia and Titanium Abutments with Different Diameters

2015 ◽  
Vol 16 (8) ◽  
pp. 613-618 ◽  
Author(s):  
Safoura Ghodsi ◽  
Reza Shabanpour ◽  
Niloufar Mousavi ◽  
Marzieh Alikhasi
Keyword(s):  
Fracture Resistance ◽  
Comparative Evaluation ◽  
Failure Modes ◽  
Statistical Significance ◽  
Testing Machine ◽  
Modes Of Failure ◽  
Body Fracture ◽  
Mode Of Failure ◽  
Different Diameters ◽  
Abutment Screw

ABSTRACT Aim The purpose of the current study was to compare the fracture resistance and mode of failure of zirconia and titanium abutments with different diameters. Materials and methods Fourteen groups of abutments including prefabricated zirconia, copy-milled zirconia and titanium abutments of an implant system (XiVE, Dentsply) were prepared in different diameters. An increasing vertical load was applied to each specimen until failure occurred. Fracture resistance was measured in each group using the universal testing machine. Moreover, the failure modes were studied and categorized as abutment screw fracture, connection area fracture, abutment body fracture, abutment body distortion, screw distortion and connection area distortion. Groups were statistically compared using univariate and post-hoc tests. The level of statistical significance was set at 5%. Results Fabrication method (p = 0.03) and diameter (p < 0.001) had significant effect on the fracture resistance of abutments. Fracture resistance of abutments with 5.5 mm diameter was higher than other diameters (p < 0.001). The observed modes of failure were dependent on the abutment material as well. All of the prefabricated titanium abutments fractured within the abutment screw. Abutment screw distortion, connection area fracture, and abutment body fracture were the common failure type in other groups. Conclusion Diameter had a significant effect on fracture resistance of implant abutments, as abutments with greater diameters were more resistant to static loads. Copy-milled abutments showed lower fracture resistance as compared to other experimental groups. Clinical significance Although zirconia abutments have received great popularity among clinicians and even patients selecting them for narrow implants should be with caution. How to cite this article Shabanpour R, Mousavi N, Ghodsi S, Alikhasi M. Comparative Evaluation of Fracture Resistance and Mode of Failure of Zirconia and Titanium Abutments with Different Diameters. J Contemp Dent Pract 2015;16(8):613-618.

scholarly journals Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-ceramic Material

2016 ◽  
Vol 17 (11) ◽  
pp. 920-925 ◽  
Author(s):  
Bandar MA Al-Makramani ◽  
Fuad A Al-Sanabani ◽  
Abdul AA Razak ◽  
Mohamed I Abu-Hassan ◽  
Ibrahim Z AL-Shami ◽  
...  
Keyword(s):  
Bond Strength ◽  
Ceramic Material ◽  
Failure Modes ◽  
Testing Machine ◽  
Surface Treatments ◽  
Resin Cement ◽  
Control Group ◽  
Significant Difference ◽  
All Ceramic ◽  
Effect Of Surface

ABSTRACT Aim The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan). Materials and methods Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. Results The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups. Conclusion In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks. Clinical significance The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations. How to cite this article Razak AAA, Abu-Hassan MI, AL-Makramani BMA, AL-Sanabani FA, AL-Shami IZ, Almansour HM. Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-Ceramic Material. J Contemp Dent Pract 2016;17(11):920-925.

scholarly journals A Novel Modular eNose System Based on Commercial MOX Sensors to Detect Low Concentrations of VOCs for Breath Gas Analysis

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 993 ◽  
Author(s):  
Carsten Jaeschke ◽  
Oriol Gonzalez ◽  
Johannes J. Glöckler ◽  
Leila T. Hagemann ◽  
Kaylen E. Richardson ◽  
...  
Keyword(s):  
Sensor Array ◽  
Gas Analysis ◽  
Exhaled Breath ◽  
Pattern Recognition Methods ◽  
Low Concentrations ◽  
Physical Sensors ◽  
Sensor Signals ◽  
Breath Gas Analysis ◽  
New Generation ◽  
Mox Sensors

In this work, a new generation of eNose systems particularly suited for exhaled breath gas analysis is presented. The developed analyzer system comprises a compact modular, low volume, temperature controlled sensing chamber explicitly tested for the detection of acetone, isoprene, pentane and isopropanol. The eNose system sensing chamber consists of three compartments, each of which can contain 8 analog Metal Oxide (MOX) sensors or 10 digital MOX sensors. Additional sensors within the digital compartment allow for pressure, humidity and temperature measurements. The presented eNose system contains a sensor array with up to 30 physical sensors and provides the ability to discriminate between low VOC concentrations under dry and humid conditions. The MOX sensor signals were analyzed by pattern recognition methods.

scholarly journals A Novel Manufacturing Technique to Improve Bearing Strength of Pin Loaded Woven Composites

2011 ◽  
Vol 20 (3) ◽  
pp. 096369351102000 ◽  
Author(s):  
Ercan Sevkat ◽  
Malek Brahimi ◽  
Sidi Berri
Keyword(s):  
Failure Modes ◽  
Hole Diameter ◽  
Woven Composites ◽  
Sustained Load ◽  
Hole Drilling ◽  
Geometrical Parameters ◽  
Composite Joints ◽  
Bearing Strength ◽  
Manufacturing Technique ◽  
Glass Fibre Reinforced

The bearing strength of pin-loaded woven glass-fibre reinforced epoxy composites was investigated. As an alternative to the hole-drilling procedure, a novel composite manufacturing technique has been implemented for pin-hole creation. The bearing performance of composite joints manufactured using both techniques was compared. Specimen with various edge- distances to pin-hole diameter ratios (e/d) and, width to pin-hole diameter ratios (w/d) were tested. It was observed that composite joints manufactured using the novel technique sustained more load compared to the joints manufactured by the hole-drilling procedure. Geometrical parameters were found to be effective on failure modes, bearing strength and magnitude of sustained load.

scholarly journals Tensile Resistance of GFRP Wrapped Steel-Dowelled Half-Lap Timber Connection

2018 ◽  
Vol 7 (3.11) ◽  
pp. 101
Author(s):  
Amirah Ali Chew ◽  
Nurul Atikah Seri ◽  
Wan Nur Syazni Wan Shaari ◽  
Mohd Hanafie Yasin ◽  
Rohana Hassan
Keyword(s):  
Testing Machine ◽  
Yield Model ◽  
Strength Group ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Load Carrying ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Group 5 ◽  
Timber Connections

Generally, the use of timber mainly focuses on simple structures or structures that can take small loads. This paper report on tensile resistance of steel dowelled timber connection wrapped with glass fibre reinforced polymer (GFRP). It involved experimental work in laboratory designed to determine the tensile strength behaviour for half-lap timber connections with steel dowel as the mechanical    fasteners. Bintangor species representing strength group 5 and Yellow Meranti species representing strength group 6 were tested in the conditions of with and without the GFRP wrapping. The performances of the connections were observed using the European Yield Model (EYM) as the guideline. The EYM theory is generally used to determine the load carrying capacity of timber-to-timber, panel-to-timber and steel-to-timber connections, reflecting all possible modes of failures. All half-lap connection members were tested at the rate     0.0006 mm/min using the universal testing machine. As a result, it was found that the steel-dowelled half-lap timber connection with GFRP wrapping performed better than the timber connection without the wrapping. The ultimate load of GFRP wrapped connections made of Bintangor and Yellow Meranti species were found increased at 17% and 44% higher compared to the connection without the GFRP wrapping accordingly.  

Influence of Hybridisation and Test Geometry on the Impact Response of Glass-Fibre-Reinforced Laminated Composites

2002 ◽  
Vol 10 (4) ◽  
pp. 259-272 ◽  
Author(s):  
Bernard Schrauwen ◽  
Pascal Bertens ◽  
Ton Peijs
Keyword(s):  
Glass Fibre ◽  
Test Set ◽  
Impact Behaviour ◽  
Impact Tests ◽  
Hybrid Laminates ◽  
Glass Fibre Reinforced ◽  
Weight Impact ◽  
Set Up ◽  
Falling Weight ◽  
The Impact

This paper describes the results of falling weight impact tests (FWITs) on glass-fibre-reinforced (GRP) laminates and E-glass/Dyneema® hybrid laminates. The test programme consisted of (i) falling weight impact tests to determine the penetration energy and (ii) experiments to determine the influence of hybrid construction on damage development and impact fatigue lifetime under repeated impact conditions at sub-penetration energy levels. The objective of this work was to investigate the effect of hybridisation on the impact behaviour of GRP laminates as well as to find optimal conditions for hybridisation. It was shown that in the case of a rigid test set-up - and hence small deflections - the influence of the Dyneema® on the impact behaviour of hybrid laminates is rather small because damage processes are the result of local contact stresses in the vicinity of the impact body, whereas in the case of a compliant test set-up and large deflections the high energy storage capacity of the ductile Dyneema® fibres is used far more effectively for the protection of hybrid composite laminates. Therefore, it was concluded that in order to fully utilise the potential of high-performance polyethylene fibres it is essential that these fibres are located on the (non-impacted) tensile side of an impacted laminate and that the geometrical test conditions are such that large (bending) deformations are allowed.

scholarly journals Effect of Combining Fiber and Textile Reinforcement on the Flexural Behavior of UHPC Plates

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Tamás Mészöly ◽  
Sandra Ofner ◽  
Norbert Randl ◽  
Zhiping Luo
Keyword(s):  
Failure Modes ◽  
Testing Machine ◽  
Fiber Reinforcement ◽  
High Strength ◽  
Image Correlation ◽  
Flexural Behavior ◽  
Textile Reinforced Concrete ◽  
Four Point Bending ◽  
Flexural Tests ◽  
Photogrammetric Measurement

A series of flexural tests were performed in order to investigate the effect of steel fiber reinforcement (SFR) in textile-reinforced concrete (TRC) plates. Some of the specimens were reinforced only with textile, some of them only with fibers, and some of them were provided with both textile and fiber reinforcement. The concrete matrix was a self-developed ultrahigh performance concrete (UHPC) mixture with a compression strength over 160 MPa. The tensile strength of the used textiles was around 1500 MPa for glass fiber textile and over 3000 MPa for carbon fiber textile. In case of fiber reinforcement, the concrete was reinforced with 2 vol% of 15 mm long and 0.2 mm diameter plain high strength steel fibers. The dimensions of the rectangular plate test specimens were 700 × 150 × 30 mm. The plate specimens were tested in a symmetric four-point bending setup with a universal testing machine. The tests were monitored using a photogrammetric measurement system with digital image correlation (DIC). The paper presents and evaluates the test results, analyses the crack patterns and crack development, and compares the failure modes. The results showed a general advantageous mechanical behavior of specimens reinforced with the combination of fibers and textiles in comparison to the specimens reinforced with only fiber or textile reinforcement.

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