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عنوان فارسی مقاله:
اثر سنجش فاصله آلومینیوم - سنسورهای پوشش داده شده FBG نصب شده بر روی یک بشقاب کامپوزیت تحت تاثیر سرعت پایین
عنوان انگلیسی مقاله:
Effect of sensing distance of aluminum-coated FBG sensors installed on a composite plate under a low-velocity impact
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Fiber reinforced polymer (FRP) composites exhibit excellent mechanical properties such as high specific stiffness, high strength, and fatigue and corrosion resistance. This has led to their widespread use in many fields [3–6], especially in aerospace engineering [7,8]. However, composite structures are susceptible to damage from external impact loadings. Low-velocity impacts can cause impact-induced damage such as fiber breakage, matrix cracking, fiber-matrix debonding, and delamination. These damages are sometimes referred to as ‘‘barely visible impact damages (BVID)” because they cannot be visually inspected. In the author’s previous studies [1,9,10], the author proposed a methodology using a metal-coated optical fiber sensor (MCOFS) to evaluate impact-induced damages of composite structures under low-velocity impacts and quasi-static indentation. Furthermore, Choi et al. [2] proposed aluminum (Al)-packaged Brillouin optical correlation domain analysis (BOCDA) sensors by using a similar approach. The BOCDA sensors were based on the Brillouin scattering effect [11–13], and it was demonstrated that Al-packaged OFS achieved a spatial resolution of 2 cm and could successfully produce residual strains of the sensors following the impact tests. These methodologies for damage evaluation and detection using MCOFS were based the ‘‘memory effects” of an elasto-plastic metal coated on the surface of optical fiber sensors. That is, the impactinduced damages could be assessed by measuring residual strain values since the maximum strains as well as the impact energy experienced by composite structures were correlated with the residual strain values [1,2,9,10,14]. This implied that the MCOFS could recall the information of the impact events that occurred in the past. This phenomenon is referred to as the ‘‘memory effects”. The methodology using MCOFS could be applied to the composite structures during operating periods and especially during inoperative periods. However, previous laboratory tests for the proposed methodology were primarily conducted by focusing on the feasibility of the methodology under limited conditions [1,2,9,10,14–16]. This study builds on the previous feasibility studies and investigates the effect of the sensing distance of multiplexed Al-coated FBG sensors from the impact point. The sensing distance can be an important factor when the sensors are in operation because the mechanicalbehaviors and responses of MCOFS can significantly vary according to the distance between an impact point and a sensing position. Additionally, prior to actual usage, it should be verified that the structural vibration induced by the external impact does not significantly affect the residual strain producing characteristics of the sensors with respect to the sensing distance. This ensures that the sensors are able to recollect the past impact information experienced by composite structures. Fig. 1 shows a prime example of an actual application of MCOFS for damage evaluation of a composite cylinder. As shown in Fig. 1 (a), a distributed type of MCOFS was preferred for damage evaluation and detection because it covers a wide area range. Fig. 1(b) shows the actual application of an Al-packaged distributed sensor for the impact detection of a composite cylinder. However, the actual application of the MCOFS continues to be limited because the effect of the sensing distance on the residual strains is not well established. Thus, it is necessary to examine the sensing distance to understand how the residual strains induced by the metal coating should be varied with respect to the sensing distance prior to an actual application. This study focused on a type of MCOFS, namely a multiplexed Al-coated fiber Bragg grating (FBG) sensor, in order to examine the effect of sensing distance. The reason for using multiplexed FBG sensors instead of distributed sensors was because the sensing capability of the former significantly exceeded that of the latter. Furthermore, a commercial interrogator system for FBG sensors provides excellent measurement resolution. Low-velocity impact tests for a composite plate with three Al-coated FBG sensors were performed to investigate the effect of sensing distance. The behavior of the composite plate with respect to the impacts was validated with the numerical results calculated by a finite element analysis (FEA) based on a continuum damage mechanics (CDM) considering damage model. The study also involved examining structural responses and strain distributions of the composite plate. Finally, the effect of the sensing position on the residual strains induced by three multiplexed Al-coated FBG sensors was investigated, and the relationship between the residual strains and sensing position was examined.
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کلمات کلیدی:
Temperature Sensing of Metal-Coated Fiber Bragg Grating - IEEE Xplore ieeexplore.ieee.org/iel5/3516/4785241/05454416.pdf?arnumber=5454416 tures, FBG sensors must be protected and metal coating is one of the most efficient ... grating (FBG) are attracting increasing interest in wide range of areas. The. [PDF]Polyimide-Coated Fiber Bragg Grating Sensors for ... - InTechOpen cdn.intechopen.com/.../InTech-Polyimide_coated_fiber_bragg_grating_sensors_for_... by L Wang - 2012 - Cited by 3 - Related articles detecting vibration signal in a wider frequency range, such as ranging from 5 Hz to ... and sensing principles of polyimide-coated FBG humidity sensor as well as ..... the moisture in oil may induce the corrosion on the surfaces of metal parts in ... [PDF]Download pdf - Heriot-Watt University https://researchportal.hw.ac.uk/.../Temperature_and_Strain_Measurements_with_Fibre... by D Havermann - Cited by 16 - Related articles sensors, Bragg gratings, strain sensors, temperature sensors, embedded fiber sensors, stainless steel ... approach of protecting the optical fibres with metal jackets ... temperature embedding processes inherently limit the range of applications that ... coating fibres containing FBGs the Bragg wavelength after nickel coating is ... Towards sensor array materials: can failure be delayed? - IOPscience iopscience.iop.org/article/10.1088/1468-6996/16/3/034607/pdf by S Mekid - 2015 - Cited by 7 - Related articles Jun 2, 2015 - Sensitivity alteration of fiber Bragg grating sensors with additive micro-scale bi-material · coatings ..... this technique, the maximum sensing distance is 8 km with a ..... The chemical plated fiber was embedded in aluminum;. Encyclopedia of Polymer Science and Technology, Concise https://books.google.com/books?isbn=0470073691 Herman F. Mark - 2013 - Science Murukeshan and co-workers describe a fiber Bragg grating sensor system with ... will retain the required processing parameters) can range from hours to days. ... are placed onto a metal tool, usually aluminum, coated with a release agent.
