37 results on '"micro-bending"'
Search Results
2. Micro-Bending Effect on the Field and Energy of Weakly Guiding Optical Fiber with a Gradient Profile in Single-Mode Regime
- Author
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Vyacheslav A. Gladkikh and Victor D. Vlasenko
- Subjects
weakly guiding optical fiber ,single-mode regime ,micro-bending ,graded index ,helmholtz equation ,green’s function ,relative energy ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Technology (General) ,T1-995 - Abstract
Introduction. Optical fibers are widely used for high-bandwidth transmitting communication signals over long distances. The key feature enabling this performance is signal low attenuation, that is signals experience minimal power loss propagating along the optical fiber. One of the factors influencing power loss during information transmission is the fiber bending. Bending can increase the signal transmission power loss of an optical fiber because of both macrobending and microbending. Studying the dependence of signal power losses when bending on waveguide parameters makes it possible to control the signal power losses of an optical fiber during information transmission. Aim of the Study. The study ia aimed at evaluating the effect of microbending on the field and energy of a weakly guiding optical fiber with a gradient refractive index profile in a single-mode regime. Materials and Methods. From the equations for the fields of straight and curved sections of weakly guiding fiber for an arbitrary gradient profile of the refractive index with the help of the subsequent solution of inhomogeneous Helmholtz equations by the Green’s function method, there were obtained expressions for relative energy: the ratio of the field energy of the fiber curved section to the field energy of the fiber straight section (in the first approximation for a single-mode regime). Results. The obtained expression for the relative energy depends on two parameters: the waveguide parameter and the ratio of the optical fiber radius to the radius of curvature. For the quadratic case of a power-law profile, as the closest to the actually used one, numerical calculations were used to construct the dependences of the relative energy on the parameter characterizing the bending for different values of the waveguide parameter. Discussion and Conclusion. It has been shown that in the case of microbending, the longer the wavelength or the smaller the fiber radius, the lower the losses. The results obtained can be used in calculating optical fiber profiles designed to operate in a bent state and eliminate expensive experimental modeling of light guides and in designing waveguides to solve specific applications, in particular, to increase energy efficiency, reliability and performance of the measuring instruments.
- Published
- 2024
- Full Text
- View/download PDF
3. High performance of SPR-based optical fiber pressure sensor: role of silicone rubber diaphragm.
- Author
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Younus, Marwan Hafeedh, Ameen, Odai Falah, and Ahmed, Zeyad Tareq
- Subjects
- *
PRESSURE sensors , *FIBER optical sensors , *OPTICAL fiber detectors , *SILICONE rubber , *OPTICAL coatings , *OPTICAL fibers , *SURFACE plasmon resonance - Abstract
The high-sensitivity surface plasmon resonance-based optical fiber sensors for micro-pressure sensing is presented in this paper. The periodic micro-bending of two mechanical periodicities with length of 5 mm and 10 mm were used in the sensing system. The micro-pressure has been applied on the sensor for three different configurations: unclad sensor without gold (Au), unclad sensor with Au, and sensor with Au sandwiched between two layers of silicon rubber. The normalized output intensity for all configurations was calculated. The results show that the higher range of applied micro-pressure can be obtained for the configuration of optical fiber coated with Au sandwiched between two layers of silicon rubbers, with maximum sensitivity of 0.65 dB/kPs. The development model of the sensor could be a promising path for many different applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Influence of the evolution of near-surface rail wheel microstructure on crack initiation by micro-bending investigations.
- Author
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Freisinger, Matthias, Trausmuth, Andreas, Hahn, Rainer, and Badisch, Ewald
- Abstract
Severe mechanical and thermal loadings, as well as the corrosive environment change the near-surface microstructure of rail wheels during service. Resulting severely plastically deformed (SPD) and corrosion affected microstructures are prone to influence crack initiation along the wheel tread. To evaluate the crack initiation and fracture behaviour, the in-situ micro-bending method is first applied on rail wheel samples from field within this work. Results reveal detailed insights in material behaviour of SPD microstructures, where the conducted micro-bending investigations point out predominant plastic behaviour without cracks initiated at the artificial notch of the micro-cantilevers during bending. In contrast, micro-bending investigations in microstructural regions with increased oxygen and silicon composition show crack initiation, fracture, and low maximum stress levels (approximately one seventh of the SPD microstructure). The presented study underlines the increased risk of crack initiation in corrosion affected regions by a novel testing method in this field with high spatial resolution and acknowledge the importance of periodic reprofiling of the rail wheels in service. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Research on the Springback Behavior of 316LN Stainless Steel in Micro-Scale Bending Processes.
- Author
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Guo, Shubiao, Tian, Chenchen, Pan, Haitao, Tang, Xuefeng, Han, Lu, and Wang, Jilai
- Subjects
- *
STAINLESS steel , *FUEL cells , *STRAINS & stresses (Mechanics) , *METALWORK , *BEHAVIORAL research , *SHEET metal - Abstract
Hydrogen fuel cells have been used worldwide due to their high energy density and zero emissions. The metallic bipolar plate is the crucial component and has a significant effect on a cell's efficiency. However, the springback behavior of the metallic bipolar plate will greatly influence its forming accuracy in the micro-scale sheet metal forming process. Therefore, accurate calculation of the springback angle of the micro-scale metallic bipolar plate is urgent but difficult given the state of existing elastoplastic theory. In this paper, a constitutive model that simultaneously considers grain size effect and strain gradient is proposed to analyze micro-scale bending behavior and calculate springback angles. The specialized micro-scale four-point bending tool was designed to better calculate the springback angle and simplify the calculation step. A pure micro-bending experiment on a 316LN stainless steel sheet with a thickness of 0.1 mm was conducted to verify the constitutive model's accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
6. Enhanced fiber mounting and etching technique for optimized optical power transmission at critical cladding thickness for fiber-sensing application.
- Author
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Arif Riza, Muhammad, Go, Yun Ii, Maier, Robert R J, Harun, Sulaiman Wadi, and Ahmad Anas, Siti Barirah
- Abstract
Optical fibers offer various applications to cater to industrial needs, from power and data transmission to environmental sensing. Different sensing mechanisms of optical fibers depend on modifications made to the fiber itself primarily in the cladding and core sections. Different types of optical fiber sensors may require thinning of the cladding to allow propagated light to interact closer to the environmental stimuli. Chemical etching is commonly used for the de-cladding of a fiber, and there are many ways to execute this method. A conventional method of chemical etching is typically used for cladding removal. This paper reports and discusses the effectiveness of enhanced techniques for improvement towards conventional chemical etching methods with the assistance of a makeshift fiber holder. The fiber holder allows the fiber to be oriented well, allowing for smoother etching and thus conserving its mechanical structure. Thickness reduction is seen to be more consistent when the enhanced technique is employed, and the fiber takes a longer time (âĽ45 min) to break. This allows etching of the cladding close to the core, which is more manageable for the user if very thin cladding is required. A fiber etched without any holder tends to break earlier (âĽ35 min) than expected with a rather wide error margin. The lower coefficient of determination, R
2 values (95%) of the thickness reduction from conventional etching shows irregular thickness along the fibers. Optical power also fluctuates between 30â€"35 dBm for the conventional method, while the mounted fiber technique maintains stable optical power at 50 dBm during etching. Therefore, it is concluded that proper fiber horizontal fiber orientation during etching has a significant effect on the fiber strength due to the smooth cladding removal around the corecore while minimizing any permanent power loss to or the occurrence of fluctuations in the fiber. This smooth and efficient etching technique allows the production of enhanced fiber sensors with minimal structural or power defects. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
7. Optimisation of micro W-bending process parameters using I-optimal design-based response surface methodology.
- Author
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Xiaoyu Liu, Xiao Han, Shiping Zhao, Yi Qin, Wan-Adlan Wan-Nawang, and Tianen Yang
- Subjects
RESPONSE surfaces (Statistics) ,EXPERIMENTAL design ,GRAIN size ,ORDER picking systems - Abstract
There is an increasingly recognised requirement for high dimensional accuracy in micro-bent parts. Springback has an important influence on dimensional accuracy and it is significantly influenced by various process parameters. In order to optimise process parameters and improve dimensional accuracy, an approach to quantify the influence of these parameters is proposed in this study. Experiments were conducted on a micro W-bending process by using an I-optimal design method, breaking through the limitations of the traditional methods of design of experiment (DOE). The mathematical model was established by response surface methodology (RSM). Statistical analysis indicated that the developed model was adequate to describe the relationship between process parameters and springback. It was also revealed that the foil thickness was the most significant parameter affecting the springback. Moreover, the foil thickness and grain size not only affected the dimensional accuracy, but also had noteworthy influence on the springback behaviour in the micro W-bending process. By applying the proposed model, the optimum process parameters to minimize springback and improve the dimensional accuracy were obtained. It is evident from this study that the I-optimal design based RSM is a promising method for parameter optimisation and dimensional accuracy improvement in the micro-bending process. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
8. Design and Applicability of Multi-Core Fibers With Standard Cladding Diameter.
- Author
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Matsui, Takashi, Sagae, Yuto, Sakamoto, Taiji, and Nakajima, Kazuhide
- Abstract
We show the design and applicability of multi-core fiber (MCF) with the standard 125 μm cladding diameter to the telecommunication systems. It offers easier and practical use of the space-division multiplexing (SDM) technology given its excellent fiber productivity and utilization of existing standard technologies. We numerically and experimentally reveal that the simple step-index (SI) profile enables us to allocate four cores in the standard 125 μm cladding and to realize full compliance with G.657.A1 fiber. We then expand the design and concept of the standard cladding MCF and show the index profile and single-mode bandwidth offer control of XT characteristics. We elucidate the application scope of the standard cladding MCF for not only the full-band (O-L band) application to short-reach and terrestrial transmission consistent with ITU-T Recommendations G.652 and G.657, but also ultra-long haul transmission, such as submarine systems compliant with ITU-T Recommendation G.654. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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9. Unveiling the mechanical properties of near-surface microstructures in tribological contacts via in-situ micro-bending tests.
- Author
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Freisinger, Matthias, Rodríguez Ripoll, Manel, and Hahn, Rainer
- Subjects
- *
TRIBOLOGY , *ROLLER bearings , *MICROSTRUCTURE , *PLASTICS , *FAILURE (Psychology) - Abstract
This study demonstrates the application of the in-situ V-notched micro-cantilever bending method in tribology by analyzing three distinct cases of near-surface microstructures occurring in common tribological contacts. The brown etching layer region of a rail wheel from service shows predominant plastic material behavior. Significant variations in material response and crack initiation are revealed in distinctive regions of a roller bearing's near-surface microstructure and a self-lubricating laser cladding. Qualitative analysis and stress-displacement graphs highlight the method's potential for gaining high-resolution insights into material behavior, contributing to our understanding of microstructural changes affecting friction, wear, and component failure in tribosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Micro-bending sensor made from polydimethylsiloxane.
- Author
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NOVAK, Martin, JARGUS, Jan, NEDOMA, Jan, VASINEK, Vladimir, MARTINEK, Radek, and STOLARIK, Martin
- Subjects
MANUFACTURING processes ,DETECTORS ,POLYDIMETHYLSILOXANE ,MICROWAVE devices - Abstract
Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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- View/download PDF
11. Strength limits in mesoscaled 3Y-TZP ceramics for micro-surgical instruments.
- Author
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Antolino, N., Muhlstein, C., Hayes, G., Adair, J., and Bermejo, R.
- Subjects
CERAMICS ,GRAIN size ,WEIBULL distribution ,RAMAN spectroscopy ,FRACTURE mechanics - Abstract
Abstract Micro-surgical instruments are a new application for mesoscale ceramics formed using the lost mold-rapid infiltration forming (LM-RIF) process. Instrument strength and reliability are the foremost concerns for this sensitive application. It is hypothesized that increasing grain size can improve the damage tolerance of the parts associated with the transformation toughening in the 3Y-TZP material, while retaining high strength. In this work, mesoscale bend bars (314 × 22 × 18 µm) of 3Y-TZP fabricated using the LM-RIF process were heat treated at 1400 °C for 1 h, 8 h, or 16 h, respectively, to obtain samples with different grain sizes. Strength tests were performed under three-point bending and results were evaluated using Weibull statistics. Fractographic and confocal Raman spectroscopic analyses were carried out to interpret the data. Experimental findings showed that the characteristic strength decreased with increasing grain size contrary to the damage tolerance hypothesis. An Orowan-Petch model was recalled to correlate the strength with the flaw size to grain size ratio. At fine grain sizes the strength was controlled by the flaws introduced by the LM-RIF process, whereas at large grain sizes the strength become more grain size controlled. Although larger-grained samples did have a higher propensity to transform, and thus increase toughening, exaggerated grain growth in some of the specimens tested caused an additional flaw population which led to an overall lower strength. Finally, based on the experimental observations and fracture mechanics considerations, we believe that an upper bound of ∼2.5 GPa exists for the strength of mesoscale as-fabricated 3Y-TZP ceramic parts. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
12. Optimisation of micro W-bending process parameters using I-optimal design-based response surface methodology
- Author
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Liu Xiaoyu, Han Xiao, Zhao Shiping, Qin Yi, Wan-Nawang Wan-Adlan, and Yang Tianen
- Subjects
micro-forming ,micro-bending ,springback ,response surface methodology ,i-optimal design ,optimisation ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Technology (General) ,T1-995 ,Manufactures ,TS1-2301 - Abstract
There is an increasingly recognised requirement for high dimensional accuracy in micro-bent parts. Springback has an important influence on dimensional accuracy and it is significantly influenced by various process parameters. In order to optimise process parameters and improve dimensional accuracy, an approach to quantify the influence of these parameters is proposed in this study. Experiments were conducted on a micro W-bending process by using an I-optimal design method, breaking through the limitations of the traditional methods of design of experiment (DOE). The mathematical model was established by response surface methodology (RSM). Statistical analysis indicated that the developed model was adequate to describe the relationship between process parameters and springback. It was also revealed that the foil thickness was the most significant parameter affecting the springback. Moreover, the foil thickness and grain size not only affected the dimensional accuracy, but also had noteworthy influence on the springback behaviour in the micro W-bending process. By applying the proposed model, the optimum process parameters to minimize springback and improve the dimensional accuracy were obtained. It is evident from this study that the I-optimal design-based RSM is a promising method for parameter optimisation and dimensional accuracy improvement in the micro-bending process.
- Published
- 2021
- Full Text
- View/download PDF
13. Analytical Formulas for Micro-Bending and Surface Scattering Loss Estimation in Tube Lattice Fibers
- Author
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Federico Melli, Lorenzo Rosa, and Luca Vincetti
- Subjects
Tube lattice fibers ,Scaling laws ,Hollow-core fibers ,Indexes ,Finite-element method ,Analytical model ,Atomic and Molecular Physics, and Optics ,Claddings ,Optical fiber communication ,Micro-bending ,Optical fiber communication, Couplings, Claddings, Estimation, Indexes, Analytical model, Micro-bending, Surface scattering loss, Hollow-core fibers, Tube lattice fibers, Scaling laws, Finite-element method, Inhibited coupling, Negative curvature fibers ,Couplings ,Surface scattering loss ,Inhibited coupling ,Negative curvature fibers ,Estimation - Published
- 2023
14. Promoted bending strength in micro-cantilevers composed of nanograined gold toward MEMS applications.
- Author
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Asano, Keisuke, Tang, Haochun, Chen, Chun-Yi, Nagoshi, Takashi, Chang, Tso-Fu Mark, Yamane, Daisuke, Konishi, Toshifumi, Machida, Katsuyuki, Masu, Kazuya, and Sone, Masato
- Subjects
- *
CANTILEVERS , *GOLD films , *MICROELECTROMECHANICAL systems , *ELECTROPLATING , *YIELD stress - Abstract
In this research, micro-bending tests of electrodeposited gold with various crystal structure were conducted using micro-cantilever specimens with dimensions at 10 μm × 10 μm × 50 μm for design of gold-based movable structures in MEMS devices. The gold film fabricated by pulse-current electrodeposition with a sulfite-based gold electrolyte (PE-Su) had the finest average grain size, which was at 15.5 nm. The PE-Su gold micro-cantilever showed ductile deformation behavior and the highest yield stress, which was at 800 MPa, because of the grain boundary strengthening mechanism also known as the Hall-Petch relationship. The gold film fabricated by constant-current electrodeposition with a cyanide-based gold electrolyte (CE-Cy) had an average grain size at 17.6 nm. The CE-Cy gold micro-cantilever showed brittle fracture and the yield stress at 480 MPa. The brittle fracture was suggested to be a result of the columnar texture structure in the CE-Cy gold film. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
15. Research on the Springback Behavior of 316LN Stainless Steel in Micro-Scale Bending Processes
- Author
-
Shubiao Guo, Chenchen Tian, Haitao Pan, Xuefeng Tang, Lu Han, and Jilai Wang
- Subjects
micro-bending ,size effect ,springback ,strain gradient ,constitutive model ,General Materials Science - Abstract
Hydrogen fuel cells have been used worldwide due to their high energy density and zero emissions. The metallic bipolar plate is the crucial component and has a significant effect on a cell’s efficiency. However, the springback behavior of the metallic bipolar plate will greatly influence its forming accuracy in the micro-scale sheet metal forming process. Therefore, accurate calculation of the springback angle of the micro-scale metallic bipolar plate is urgent but difficult given the state of existing elastoplastic theory. In this paper, a constitutive model that simultaneously considers grain size effect and strain gradient is proposed to analyze micro-scale bending behavior and calculate springback angles. The specialized micro-scale four-point bending tool was designed to better calculate the springback angle and simplify the calculation step. A pure micro-bending experiment on a 316LN stainless steel sheet with a thickness of 0.1 mm was conducted to verify the constitutive model’s accuracy.
- Published
- 2022
16. Investigation of Micro-Bending of Sheet Metal Laminates by Laser-Driven Soft Punch in Warm Conditions.
- Author
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Huixia Liu, Guoce Zhang, Zongbao Shen, Wenhao Zhang, and Xiao Wang
- Subjects
SHEET metal ,LAMINATED materials - Abstract
Microscale laser dynamic flexible forming (μLDFF) is a novel ultrahigh strain rate manufacturing technology with high efficiency and low cost. However, the μLDFF is just confined to single-layer foil at present. In this work, sheet metal laminates (Cu/Ni) were selected as the experimental material for its excellent mechanical and functional properties, and a new micro-bending method of sheet metal laminates by laser-driven soft punch was proposed in warm conditions. The micro-mold and warm platform were designed to investigate the effects of temperature and energy on formability, which were characterized by forming accuracy, surface quality, element diffusion, and so on. The experimental results show that the forming accuracy and quality increased first and then decreased with laser energy, but the hardness increased consistently. In warm conditions, the fluidity of material was improved. The forming depth and accuracy increased for the relieved springback, and the surface quality increased first and then decreased. The tensile fracture disappeared with temperature for the decreased hardness and thinning ratio, and the element diffusion occurred. Overall, this study indicates that the formability can be improved in warm conditions and provides a basis for the investigation of micro-bending of sheet metal laminates by μLDFF in warm conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
17. The influence of microstructure on the cyclic deformation and damage of copper and an oxide dispersion strengthened steel studied via in-situ micro-beam bending.
- Author
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Howard, C., Fritz, R., Alfreider, M., Kiener, D., and Hosemann, P.
- Subjects
- *
COPPER , *STEEL , *DEFORMATIONS (Mechanics) , *BENDING (Metalwork) , *DUCTILITY , *FRACTURE toughness - Abstract
Service materials are often designed for strength, ductility, or toughness, but neglect the effects of cyclic time-variable loads ultimately leading to macroscopic mechanical failure. Fatigue originates as local plasticity that can first only be observed on the micro scale at defects serving as stress concentrators such as inclusions or grain boundaries. Thus, a recently developed technique to perform in-situ observation of micro scale bending fatigue experiments was applied. Micro-beams fabricated from copper, single grained and ultrafine grained (ufg), and an oxide dispersion strengthened (ODS) steel were subject to cyclic deformation and subsequent damage. The elastic stiffness, yield strength, dissipated energy, and maximum stress were measured as a function of cycle number and plastic strain amplitude. From these properties, cyclic stress-strain curves were developed. Initial pronounced monotonic hardening and an increasing Bauschinger effect were observed in all samples with increasing strain amplitude. Cyclic stability was maintained until plastic strain amplitudes reached a critical value. At this point, dramatic cyclic softening and microcracking occurred. The critical strain amplitude was found to be approximately 5.4×10 −3 for the copper with a refined grain structure and 1.2×10 −2 for the steel specimen. Grain rotation and noticeable changes in sub-grain structure were evident in the ufg copper after a critical strain amplitude of ε a =8.3×10 −3 . In-situ micro fatigue bending couples the cyclic evolution of bulk mechanical properties measurements with real-time electron microscopy analysis techniques of damage and failure mechanisms, which renders it a powerful method for developing novel fatigue resistant materials. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
18. A finite element framework for distortion gradient plasticity with applications to bending of thin foils.
- Author
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Martínez-Pañeda, Emilio, Niordson, Christian F., and Bardella, Lorenzo
- Subjects
- *
MATERIAL plasticity , *BENDING (Metalwork) , *METAL foils , *FINITE element method , *VISCOPLASTICITY , *CURVATURE - Abstract
A novel general purpose Finite Element framework is presented to study small-scale metal plasticity. A distinct feature of the adopted distortion gradient plasticity formulation, with respect to strain gradient plasticity theories, is the constitutive inclusion of the plastic spin, as proposed by Gurtin (2004) through the prescription of a free energy dependent on Nye’s dislocation density tensor. The proposed numerical scheme is developed by following and extending the mathematical principles established by Fleck and Willis (2009). The modeling of thin metallic foils under bending reveals a significant influence of the plastic shear strain and spin due to a mechanism associated with the higher-order boundary conditions allowing dislocations to exit the body. This mechanism leads to an unexpected mechanical response in terms of bending moment versus curvature, dependent on the foil length, if either viscoplasticity or isotropic hardening are included in the model. In order to study the effect of dissipative higher-order stresses, the mechanical response under non-proportional loading is also investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
19. Numerical simulation of flexible micro-bending processes with consideration of grain structure.
- Author
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Wang, Xiao, Qian, Qing, Shen, Zongbao, Li, JianWen, Zhang, Hongfeng, and Liu, Huixia
- Subjects
- *
MICROBENDING , *COMPUTER simulation , *CRYSTAL grain boundaries , *CRYSTAL structure , *FINITE element method , *GRAIN size - Abstract
A finite element model of the flexible micro-bending process based on various grain sizes of pure copper is developed. The geometrical model of grain structure is established with Voronoi tessellation, which is employed to describe the polycrystalline aggregation. A model based on dislocation density is adopted to describe the flow stress of grain interior (GI) and grain boundary (GB) quantitatively. In this paper, silicon rubber is used as the flexible punch and four annealing conditions of pure copper as the workpieces, respectively. The influence of grain structure and grain size is discussed. It is observed that as the ratio of workpiece thickness ( t ) to grain size ( d ) decreases, the forming depth increases. The inhomogeneous deformation occurs in the coarse-grained micro-parts. Furthermore, the results indicate that the surface asperity increases with grain size. The numerical simulation results agree well with the tendency of experimental results. During the micro-bending process, the phenomenon of stress concentration occurs at the grain boundary of the micro-parts. The maximum von mises stress appears at the grain boundary located at the fillet position. The maximum von mises plastic strain primarily concentrates on the junction of the grain interior and grain boundary in the fine-grained parts, while it concentrates at the surface of the grain interior in the coarse-grained parts. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
20. Optimisation of micro W-bending process parameters using I-optimal design-based response surface methodology
- Author
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Tianen Yang, Xiaoyu Liu, Yi Qin, Wan Adlan Wan-Nawang, Shiping Zhao, and Xiao Han
- Subjects
Optimal design ,0209 industrial biotechnology ,Bending (metalworking) ,optimisation ,micro-forming ,Mechanical engineering ,02 engineering and technology ,TS ,Industrial and Manufacturing Engineering ,response surface methodology ,springback ,020901 industrial engineering & automation ,micro-bending ,lcsh:Manufactures ,lcsh:Technology (General) ,0202 electrical engineering, electronic engineering, information engineering ,Statistical analysis ,Response surface methodology ,FOIL method ,Mathematics ,i-optimal design ,Design of experiments ,020208 electrical & electronic engineering ,Process (computing) ,lcsh:TA1-2040 ,TA174 ,lcsh:T1-995 ,lcsh:Engineering (General). Civil engineering (General) ,Engineering design process ,lcsh:TS1-2301 - Abstract
There is an increasingly recognised requirement for high dimensional accuracy in micro-bent parts. Springback has an important influence on dimensional accuracy and it is significantly influenced by various process parameters. In order to optimise process parameters and improve dimensional accuracy, an approach to quantify the influence of these parameters is proposed in this study. Experiments were conducted on a micro W-bending process by using an I-optimal design method, breaking through the limitations of the traditional methods of design of experiment (DOE). The mathematical model was established by response surface methodology (RSM). Statistical analysis indicated that the developed model was adequate to describe the relationship between process parameters and springback. It was also revealed that the foil thickness was the most significant parameter affecting the springback. Moreover, the foil thickness and grain size not only affected the dimensional accuracy, but also had noteworthy influence on the springback behaviour in the micro W-bending process. By applying the proposed model, the optimum process parameters to minimize springback and improve the dimensional accuracy were obtained. It is evident from this study that the I-optimal design-based RSM is a promising method for parameter optimisation and dimensional accuracy improvement in the micro-bending process.
- Published
- 2021
21. Experimental and Numerical Investigation on Micro-Bending of AISI 304 Sheet Metal Using a Low Power Nanosecond Laser
- Author
-
Paramasivan, K., Das, Sandip, Marimuthu, Sundar, and Misra, Dipten
- Published
- 2018
- Full Text
- View/download PDF
22. Twist Sensitivity of Cladding-Mode Resonances and Its Cross-Sensitivity to Strain and Temperature in a Mechanically Induced Long-Period Fiber Grating.
- Author
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Nair, Anitha S., Kumar, V. P. Sudeep, and Joe, Hubert
- Subjects
- *
OPTICAL fiber cladding , *OPTICAL resonance , *BIREFRINGENCE , *FIBER gratings , *MICROBENDING , *TORSION , *DETECTORS - Abstract
Twist sensitivity of cladding-mode resonances in a mechanically induced long-period fiber grating formed over a single-mode fiber is experimentally demonstrated and theoretically analyzed. Of the two usual cladding-mode resonances corresponding to LP11 and LP12, higher-order mode LP12 is more sensitive to twist in comparison with the lower-order mode LP11. The extent of down-shifting of resonant wavelengths depends on twist-induced circular birefringence and the modal field distribution of the cladding-modes inside the fiber. When the fiber is severely twisted to 3.5 rad/cm, a shift sensitivity is observed of 1 nm/(rad/cm) for the LP11 mode and 4.23 nm/(rad/cm) for the LP12 mode. The fiber breaks when the twist rate exceeds 3.5 rad/cm. In comparison with LP12, the LP11 resonance is almost independent of the axial strain variation with an ultra-low sensitivity of 0.18 pm/με, and it is also almost insensitive to the temperature variation with a coefficient of 35 pm/°C. Forming the LP11 resonance far away from its cut-off wavelength, a widely tunable band-pass filter is also demonstrated with a very high twist sensitivity of 8.75 nm/(rad/cm) and negligible cross-sensitivity to strain and temperature. The experimental and theoretical results are very useful in selecting sensitive and stable cladding-mode resonances in the design of new mechanically induced long-period fiber gratings based torsion sensors and tunable band-pass filters. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
23. A comprehensive study on the effect of line energy during laser bending of duplex stainless steel.
- Author
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Yadav, Ramsingh, Goyal, Dhruva Kumar, and Kant, Ravi
- Subjects
- *
HIGH power lasers , *DUPLEX stainless steel , *ULTIMATE strength , *TEMPERATURE distribution - Abstract
• Laser bending of duplex stainless steel is explored which is not reported in the literature. • Effect of line energy on bending mechanism, bend angle, edge effect, and mechanical properties is investigated in detail. • The role of temperature distribution on the variation in bend angle, and mechanical and microstructural properties is explored. Laser bending is a well-established process to achieve bending with high accuracy and good controllability. This study discusses the effect of line energy on bending mechanism, bend angle, edge effect, mechanical properties, and microstructural characterization for laser bending of duplex stainless steel. Numerical simulations have been carried out for a better understanding of the bending mechanisms. Additionally, the role of temperature distribution at the bottom surface on the variation in bend angle has been analyzed. It is found that at low laser powers, the bend angle increases with line energy, but at a decreasing rate. Whereas at high laser powers, the bend angle increases with line energy; attains peak and then decreases. At constant line energy, the bend angle increases with the increase in laser power and scanning speed. The hardness of laser-scanned specimens is increased, and ductility is reduced. Besides, the ultimate strength and yield strength remain almost constant. The sigma phase formation has been observed during the microstructural analysis, which further correlates with the high hardness and low ductility. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
24. Numerical implementation of a 3D continuum theory of dislocation dynamics and application to micro-bending.
- Author
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Sandfeld, S., Hochrainer, T., Gumbsch, P., and Zaiser, M.
- Subjects
- *
DISLOCATIONS in crystals , *BENDING (Metalwork) , *THREE-dimensional display systems , *CRYSTAL lattices , *DENSITY - Abstract
Crystal plasticity is governed by the motion of lattice dislocations. Although continuum theories of static dislocation assemblies date back to the 1950s, the line-like character of these defects posed serious problems for the development of a continuum theory of plasticity which is based on the averaged dynamics of dislocation systems. Only recently the geometrical problem of performing meaningful averages over systems of moving, oriented lines has been solved. Such averaging leads to the definition of a dislocation density tensor of second order along with its evolution equation. This tensor can be envisaged as the analogue of the classical dislocation density tensor in an extended space which includes the line orientation as an independent variable. In the current work, we discuss the numerical implementation of a continuum theory of dislocation evolution that is based on this dislocation density measure and apply this to some simple benchmark problems as well as to plane-strain micro-bending. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
25. Cyclic response of copper single crystal micro-beams
- Author
-
Kiener, D., Motz, C., Grosinger, W., Weygand, D., and Pippan, R.
- Subjects
- *
COPPER crystals , *MINIATURE electronic equipment , *METAL fatigue , *BAUSCHINGER effect , *DISLOCATIONS in crystals , *MOLECULAR dynamics , *SIMULATION methods & models , *STRAIN hardening - Abstract
A new technique to perform in situ miniaturized bending fatigue experiments was applied to single crystal copper beams. Pronounced monotonic hardening and an increasing Bauschinger effect were observed with increasing normalized displacement. Remarkably, no cyclic hardening or softening was observed. Three-dimensional discrete dislocation dynamics simulations support these results and point out the importance of dislocation pile-ups and local hardening mechanisms. These lead to local strain redistribution and the activation of new glide planes as observed experimentally. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
26. Piezoresistive behaviour of flexible PEDOT:PSS based sensors
- Author
-
Latessa, G., Brunetti, F., Reale, A., Saggio, G., and Di Carlo, A.
- Subjects
- *
DETECTORS , *PIEZOELECTRIC devices , *ELECTRIC properties of polymers , *DEFORMATIONS (Mechanics) , *POLYMERIZATION - Abstract
Abstract: In this work we developed a low cost flexible polymeric sensor. This sensor is realized using electrochemical synthesis of a conductive polymer (PEDOT:PSS) thin film deposited on a flexible substrate of polyimide using a peeling technique. The sensor was characterized using two different setups able to evaluate the effects of microscopic and macroscopic deformation. Different ranges are considered to correctly define the behaviour and fields of application of the device, and to compare the performances with the data typically available in literature for strain sensors. Using the micro-bending setup we extracted a gauge factor of 17.8±4, which is well above the typical value for commercially available flexible metallic strain gauges on polyimide substrates. A specific setup is also presented to analyze the behaviour of the sensor with respect to macroscopic bending. We evaluated the change of the resistance of the sample varying the bending angle in the range of 0–60° both in the inward and in the outward direction. We demonstrated in both cases a linear dependence of the resistance with respect to the bending angle, and furthermore a high reproducibility with low hysteresis. Finally we evaluated in the macroscopic regime of deformation also the response time of the sensor obtaining a very good dynamic response with amplitude fluctuations less than few percent with respect to a periodic deformation. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
27. A physically based gradient plasticity theory
- Author
-
Abu Al-Rub, Rashid K. and Voyiadjis, George Z.
- Subjects
- *
MATERIAL plasticity , *DEFORMATIONS (Mechanics) , *ELASTICITY , *ELASTIC solids - Abstract
Abstract: The intent of this work is to derive a physically motivated mathematical form for the gradient plasticity that can be used to interpret the size effects observed experimentally. The step of translating from the dislocation-based mechanics to a continuum formulation is explored. This paper addresses a possible, yet simple, link between the Taylor’s model of dislocation hardening and the strain gradient plasticity. Evolution equations for the densities of statistically stored dislocations and geometrically necessary dislocations are used to establish this linkage. The dislocation processes of generation, motion, immobilization, recovery, and annihilation are considered in which the geometric obstacles contribute to the storage of statistical dislocations. As a result, a physically sound relation for the material length scale parameter is obtained as a function of the course of plastic deformation, grain size, and a set of macroscopic and microscopic physical parameters. Comparisons are made of this theory with experiments on micro-torsion, micro-bending, and micro-indentation size effects. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
28. Irradiation of Radiation-Tolerant Single-Mode Optical Fibers at Cryogenic Temperature
- Author
-
D. Ricci, Udo Weinand, Jochen Kuhnhenn, Olaf J. Schumann, Jeremy Blanc, and Publica
- Subjects
optical fiber ,Optical fiber ,Materials science ,structure defects ,02 engineering and technology ,01 natural sciences ,Temperature measurement ,radiation induced attenuation ,law.invention ,020210 optoelectronics & photonics ,Zero-dispersion wavelength ,micro-bending ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Dispersion-shifted fiber ,Fiber ,Irradiation ,010308 nuclear & particles physics ,business.industry ,Attenuation ,gamma radiation ,Single-mode optical fiber ,cryogenic temperature ,Atomic and Molecular Physics, and Optics ,Optoelectronics ,annealing ,LHC ,business - Abstract
Radiation effects at cryogenic temperature are investigated in two radiation-tolerant Fluorine-doped single-mode fibers originating from two different manufacturers. This paper presents measurements at room temperature (297 K) and at cryogenic temperature (16 K) of the radiation induced attenuation at 1312 nm and 1570 nm for both fibers. In addition to the massive increase of the optical attenuation at 16 K, the fiber is found to be in a frozen state where thermal bleaching and defect recombination no longer occurs. However, a long-term recovery, including the heating of the fiber from cryogenic temperature to room temperature, anneals a large amount of the defects created and brings the fiber back to almost its initial performance.
- Published
- 2017
- Full Text
- View/download PDF
29. Gradient plasticity theory with a variable length scale parameter
- Author
-
Voyiadjis, George Z. and Al-Rub, Rashid K. Abu
- Subjects
- *
MATERIAL plasticity , *COUPLINGS (Gearing) , *TORSION , *MECHANICS (Physics) - Abstract
Abstract: The definition and magnitude of the intrinsic length scale are keys to the development of the gradient plasticity theory that incorporates size effects. However, a fixed value of the material length-scale is not always realistic and different problems could require different values. Moreover, a linear coupling between the local and nonlocal terms in the gradient plasticity theory is not always realistic and that different problems could require different couplings. This work addresses the proper modifications required for the full utility of the current gradient plasticity theories in solving the size effect problem. It is shown that the current gradient plasticity theories do not give sound interpretations of the size effects in micro-bending and micro-torsion tests if a definite and fixed length scale parameter is used. A generalized gradient plasticity model with a non-fixed length scale parameter is proposed based on dislocation mechanics. This model assesses the sensitivity of predictions to the way in which the local and nonlocal parts are coupled (or to the way in which the statically stored and geometrically necessary dislocations are coupled). In addition a physically-based relation for the length scale parameter as a function of the course of deformation and the material microstructural features is proposed. The proposed model gives good predictions of the size effect in micro-bending tests of thin films and micro-torsion tests of thin wires. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
30. Size Effects in Micro-bending Deformation of MEMS Devices Based on the Discrete Dislocation Theory.
- Author
-
Shan Tang, Chen Zhu, and Yue-Guang Wei
- Abstract
In the present research, the discrete dislocation theory is used to analyze the size effect phenomena for the MEMS devices undergoing micro-bending load. A consistent result with the experimental one in literature is obtained. In order to check the effectiveness to use the discrete dislocation theory in predicting the size effect, both the basic version theory and the updated one are adopted simultaneously. The normalized stress-strain relations of the material are obtained for different plate thickness or for different obstacle density. The prediction results are compared with experimental results. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
31. A combined experimental-numerical approach for elasto-plastic fracture of individual grain boundaries.
- Author
-
Kupka, D., Huber, N., and Lilleodden, E.T.
- Subjects
- *
ALUMINUM-lithium alloys , *ELASTOPLASTICITY , *FRACTURE mechanics , *CRYSTAL grain boundaries , *NUMERICAL analysis , *MATERIAL plasticity , *FINITE element method , *PHYSICS research - Abstract
Abstract: The parameters for a crystal plasticity finite element constitutive law were calibrated for the aluminum–lithium alloy 2198 using micro-column compression testing on single crystalline volumes. The calibrated material model was applied to simulations of micro-cantilever deflection tests designed for micro-fracture experiments on single grain boundaries. It was shown that the load–displacement response and the local deformation of the grains, which was measured by digital image correlation, were predicted by the simulations. The fracture properties of individual grain boundaries were then determined in terms of a traction–separation-law associated with a cohesive zone. This combination of experiments and crystal plasticity finite element simulations allows the investigation of the fracture behavior of individual grain boundaries in plastically deforming metals. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
32. Micro-bending sensing based on single-mode fiber spliced multimode fiber Bragg grating structure.
- Author
-
Sun, Xiaoyan, Zhang, Limu, Zeng, Li, Hu, Youwang, and Duan, Ji-an
- Subjects
- *
FIBER Bragg gratings , *SINGLE-mode optical fibers , *OPTICAL fibers , *MANUFACTURING processes , *TEMPERATURE sensors , *OPTICAL fiber detectors - Abstract
Fiber Bragg grating (FBG) is a commonly used optical fiber sensing structure. FBG bent sensors in multimode fiber have been achieved. However, the structure and manufacturing process are complex. In the present study, we designed a simple structure that composed of an ordinary single-mode fiber (SMF) and a section of multimode fiber (MMF) with a FBG. It can realize the dual-parameter sensing of micro-bending and temperature simultaneously. The experimental results suggested that the structure is sensitive to micro-bending and temperature, and the sensitivities do not interfere with each other. The temperature sensitivity is 13.4 pm/ ∘ C, and the maximum bending sensitivity is 23.03 dB/m−1. • Micro-bending and temperature sensor is fabricated by femtosecond laser inscription. • The sensor structure is simple which including SMF and MMF with FBG. • Micro-bending and temperature sensitivity do not interfere with each other. • Temperature sensitivity is 13.4 pm/ ∘ C. Maximum bending sensitivity is 23 dB/m−1. • The sensor has excellent repeatability, reliability and measurement accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. Determination of elastic and flexural strength properties of multi-scale materials via indentation assisted micro-bending experiment and inverse analysis.
- Author
-
El Awad, Santiago, Stefaniuk, Damian, and Krakowiak, Konrad J.
- Subjects
- *
FLEXURAL strength , *MECHANICAL properties of condensed matter , *ELASTICITY , *CEMENT composites , *INHOMOGENEOUS materials , *ELASTIC modulus , *INDENTATION (Materials science) - Abstract
An original approach for mechanical characterization was developed using indentation assisted micro-bending. Aiming at the reliable measurement of elastic modulus of multi-scale solids, the technique relies on deflection measurements of cantilever-type beams modeled within the framework of beams on elastic foundation. The inference of elastic modulus is carried out by postulating the inverse problem and solving it via the error minimization approach. The validation performed on a set of reference materials disclosed the proposed technique's potential for accurate characterization of elastic properties and flexural strength at micro and mesoscale, motivating its extension to heterogeneous materials - cementitious composites in particular. [Display omitted] • The reliable instrumented assisted micro-bending technique has been developed. • The beam on Winkler-type foundation model was used as the mechanical representation. • Multi-variable inverse minimization has been used in the estimation of elastic properties. • Validation of the technique has been performed on reference construction materials. • The methodology was successfully applied to cementitious systems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Investigation of Micro-Bending of Sheet Metal Laminates by Laser-Driven Soft Punch in Warm Conditions
- Author
-
Wenhao Zhang, Xiao Wang, Huixia Liu, Zongbao Shen, and Zhang Guoce
- Subjects
micro-bending ,sheet metal laminates ,laser-driven soft punch ,springback ,element diffusion ,warm conditions ,0209 industrial biotechnology ,Work (thermodynamics) ,Materials science ,Bending (metalworking) ,lcsh:Mechanical engineering and machinery ,02 engineering and technology ,Article ,020901 industrial engineering & automation ,Formability ,lcsh:TJ1-1570 ,Electrical and Electronic Engineering ,Diffusion (business) ,Composite material ,FOIL method ,Microscale chemistry ,Mechanical Engineering ,Metallurgy ,Strain rate ,021001 nanoscience & nanotechnology ,Control and Systems Engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Sheet metal - Abstract
Microscale laser dynamic flexible forming (µLDFF) is a novel ultrahigh strain rate manufacturing technology with high efficiency and low cost. However, the µLDFF is just confined to single-layer foil at present. In this work, sheet metal laminates (Cu/Ni) were selected as the experimental material for its excellent mechanical and functional properties, and a new micro-bending method of sheet metal laminates by laser-driven soft punch was proposed in warm conditions. The micro-mold and warm platform were designed to investigate the effects of temperature and energy on formability, which were characterized by forming accuracy, surface quality, element diffusion, and so on. The experimental results show that the forming accuracy and quality increased first and then decreased with laser energy, but the hardness increased consistently. In warm conditions, the fluidity of material was improved. The forming depth and accuracy increased for the relieved springback, and the surface quality increased first and then decreased. The tensile fracture disappeared with temperature for the decreased hardness and thinning ratio, and the element diffusion occurred. Overall, this study indicates that the formability can be improved in warm conditions and provides a basis for the investigation of micro-bending of sheet metal laminates by µLDFF in warm conditions.
- Published
- 2017
35. A finite element framework for distortion gradient plasticity with applications to bending of thin foils
- Author
-
Martínez Pañeda, Emilio, Niordson, Christian Frithiof, Bardella, Lorenzo, Martínez Pañeda, Emilio, Niordson, Christian Frithiof, and Bardella, Lorenzo
- Abstract
A novel general purpose Finite Element framework is presented to study small-scale metal plasticity. A distinct feature of the adopted distortion gradient plasticity formulation, with respect to strain gradient plasticity theories, is the constitutive inclusion of the plastic spin, as proposed by Gurtin (2004) through the prescription of a free energy dependent on Nye’s dislocation density tensor. The proposed numerical scheme is developed by following and extending the mathematical principles established by Fleck and Willis (2009). The modeling of thin metallic foils under bending reveals a significant influence of the plastic shear strain and spin due to a mechanism associated with the higher-order boundary conditions allowing dislocations to exit the body. This mechanism leads to an unexpected mechanical response in terms of bending moment versus curvature, dependent on the foil length, if either viscoplasticity or isotropic hardening are included in the model. In order to study the effect of dissipative higher-order stresses, the mechanical response under non-proportional loading is also investigated.
- Published
- 2016
36. A combined experimental-numerical approach for elasto-plastic fracture of individual grain boundaries
- Author
-
D. Kupka, Erica T. Lilleodden, and Norbert Huber
- Subjects
Digital image correlation ,Materials science ,Mechanical Engineering ,Alloy ,Constitutive equation ,Elasto plastic ,Micro-compression ,Mechanics ,engineering.material ,Condensed Matter Physics ,Finite element method ,Intergranular fracture ,Micro-bending ,Finite element crystal plasticity ,Mechanics of Materials ,Deflection (engineering) ,engineering ,Grain boundary ,ddc:620.11 - Abstract
The parameters for a crystal plasticity finite element constitutive law were calibrated for the aluminum–lithium alloy 2198 using micro-column compression testing on single crystalline volumes. The calibrated material model was applied to simulations of micro-cantilever deflection tests designed for micro-fracture experiments on single grain boundaries. It was shown that the load–displacement response and the local deformation of the grains, which was measured by digital image correlation, were predicted by the simulations. The fracture properties of individual grain boundaries were then determined in terms of a traction–separation-law associated with a cohesive zone. This combination of experiments and crystal plasticity finite element simulations allows the investigation of the fracture behavior of individual grain boundaries in plastically deforming metals.
- Published
- 2014
- Full Text
- View/download PDF
37. Piezoresistive behaviour of flexible PEDOT:PSS based sensors
- Author
-
Giuseppe Latessa, A. Di Carlo, Andrea Reale, Francesca Brunetti, and Giovanni Saggio
- Subjects
Materials science ,Bending ,Settore ING-INF/01 - Elettronica ,PEDOT:PSS ,Micro-bending ,Piezoresistivity ,Materials Chemistry ,Electrical and Electronic Engineering ,Composite material ,Instrumentation ,Strain gauge ,Conductive polymer ,Metals and Alloys ,Electropolymerization ,Macro-bending ,Condensed Matter Physics ,Piezoresistive effect ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Flexible sensor ,Gauge factor ,Hysteresis ,Deformation (engineering) - Abstract
In this work we developed a low cost flexible polymeric sensor. This sensor is realized using electrochemical synthesis of a conductive polymer (PEDOT:PSS) thin film deposited on a flexible substrate of polyimide using a peeling technique. The sensor was characterized using two different setups able to evaluate the effects of microscopic and macroscopic deformation. Different ranges are considered to correctly define the behaviour and fields of application of the device, and to compare the performances with the data typically available in literature for strain sensors. Using the micro-bending setup we extracted a gauge factor of 17.8 ± 4, which is well above the typical value for commercially available flexible metallic strain gauges on polyimide substrates. A specific setup is also presented to analyze the behaviour of the sensor with respect to macroscopic bending. We evaluated the change of the resistance of the sample varying the bending angle in the range of 0–60° both in the inward and in the outward direction. We demonstrated in both cases a linear dependence of the resistance with respect to the bending angle, and furthermore a high reproducibility with low hysteresis. Finally we evaluated in the macroscopic regime of deformation also the response time of the sensor obtaining a very good dynamic response with amplitude fluctuations less than few percent with respect to a periodic deformation.
- Published
- 2009
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