Showing papers by "Jinsong Leng published in 2015"
TL;DR: In this paper, the effect of high temperature shape-memory polyimides on the basis of chain flexibility, molecular weight, and cross-link density was investigated. And the relationship between Mn and Tg was explored, which will benefit further research on high temperature SMPs.
Abstract: Shape-memory polymers (SMPs) are synthesized with adjustable glass transition temperature (Tg) ranging from 299 to 322 °C, higher than those reported previously. The polyimide containing thermal stable but flexible linkages within the backbone act as reversible phase, and high molecular weight (Mn) is necessary to form physical cross-links as fixed phase of thermoplastic shape-memory polyimide. The critical Mn is 21.3 kg/mol, and the relationship between Mn and Tg is explored. Thermoset polyimides show higher storage modulus and better shape-memory effects than thermoplastic counterparts due to covalent cross-linking, and the effective cross-link density with the influence on their physical properties is studied. The mechanism of high-temperature shape-memory effect of polyimide on the basis of chain flexibility, molecular weight, and cross-link density is proposed, which will benefit further research on high-temperature SMPs.
138 citations
TL;DR: In this paper, the shape memory effect is induced by electrical resistive heating of reduced graphene oxide paper (RGOP) possessing excellent heat conductive property and serving as a conductive layer to transmit heat to the polymer.
106 citations
TL;DR: The mechanisms of high temperature shape memory effects based on chain flexibility, molecular weight and crosslink density, and the possible mechanism of high and low temperature resistant property is discussed.
Abstract: High temperature shape memory polymers that can withstand the harsh temperatures for durable applications are synthesized and the aromatic polyimide chains with flexible linkages within the backbone act as reversible phase. High molecular weight (Mn) is demanded to form physical crosslinks as fixed phase of thermoplastic shape memory polyimide and the relationship between Mn and glass transition temperature (Tg) is explored. Thermoset shape memory polyimide shows higher Tg and storage modulus, better shape fixity than thermoplastic counterpart due to the low-density covalent crosslinking and the influence of crosslinking on physical properties are studied. The mechanism of high temperature shape memory effects based on chain flexibility, molecular weight and crosslink density is proposed. Exposure to thermal cycling from +150 °C to −150 °C for 200 h produces negligible effect on the properties of the shape memory polyimide and the possible mechanism of high and low temperature resistant property is discussed.
93 citations
TL;DR: In this paper, a zero Poisson's ratio (ZPR) honeycomb structure was proposed to achieve deformations along two orthogonal directions and avoid the increase of effective stiffness in the morphing direction by restraining the Poisson effect in the non-morphing direction.
92 citations
TL;DR: In this article, elastic fibers were mixed into pure shape memory polymers to solve the problem of micro-cracks formed under tension, and the mechanical properties of the shape memory polymer composites were investigated.
Abstract: Shape memory polymers are temperature-controlled variable stiffness materials, which have potential for use as morphing skins. Shape memory polymer skins undergo large strain in their flexible, rubbery state and resist aerodynamic loads in their stiff, glassy state. However, pure shape memory polymers are brittle in their glassy state, and in their rubbery state, they tear rapidly along micro-cracks formed under tension. Due to these disadvantages, the shape memory polymers are not safe and reliable enough for application. In this article, elastic fibers were mixed into pure shape memory polymers to solve these problems. The mechanical properties of the shape memory polymer composites were investigated. The strength and Young’s modulus of pure shape memory polymers at high temperature were improved by elastic fibers, and the toughness of pure shape memory polymers at room temperature (glassy state) was enhanced with acceptable reduction in Young’s modulus. The tear strength of shape memory polymers was si...
61 citations
TL;DR: This article investigates that the microwave heating as a novel method is used to rapidly foam and actuate biocompatible and biodegradable shape memory crosslinked-polycaprolactone (c-PCL) foams and proves that the resulting c- PCL foams have homogenous pore structure.
Abstract: Microwave technology is a highly effective approach to fast and uniform heating. This article investigates that the microwave heating as a novel method is used to rapidly foam and actuate biocompatible and biodegradable shape memory crosslinked-polycaprolactone (c-PCL) foams. The optical microscope proves that the resulting c-PCL foams have homogenous pore structure. Mechanical behavior and shape memory performance of c-PCL foams are investigated by static materials testing. Shape recovery ratio is approximately 100% and the whole recovery process takes only 98 s when trigged by microwave. Due to the unique principle of microwave heating, the recovery speed of c-PCL foams in microwave oven is several times faster than that in hot water and electric oven. Hence compared to the traditional heating methods, microwave is expected to bring more advantages to modern industry and scientific research in the field of smart materials and structures.
59 citations
TL;DR: In this article, a rotary joint for a flapping wing actuated by a dielectric elastomer minimum energy actuation mechanism is reported, and the deformation process and characteristics of the DE film during joint rotation are analyzed.
Abstract: Exhibiting high energy densities, light weight, and elegant form factor, dielectric elastomers are poised as a promising alternative to the driving of flying robots. A rotary joint for a flapping wing actuated by a dielectric elastomer minimum energy actuation mechanism is reported. The deformation process and characteristics of the dielectric elastomer during joint rotation are analyzed, and the DE film will warp like saddle surface. The geometry parameter of the rotary joint will influence voltage-induced strain of DE film, and the natural frequency will restrict dynamics performance of the joint. Additionally, experimental results validate the characteristic of above saddle surface and the influence principle. A rotary joint and a flapping wing prototype were fabricated to validate design principles, demonstrating the design principles can be used to this kind of dielectric elastomer joint and flapping wing.
58 citations
TL;DR: In this article, composite membranes with shape memory property based on biocompatible polycaprolactone and polyethylene oxide were successfully fabricated by using electrospinning technique.
Abstract: Hybrid materials with nanostructure could exhibit a diverse range of applications as advanced functional materials. This research work, composite membranes with shape memory property based on biocompatible polycaprolactone and polyethylene oxide were successfully fabricated by using electrospinning technique. Electrospun fiber configuration is strongly related to the concentration of polymer and electric field strength. The hydrophilic property of hybrid membrane has been improved and water play a critical role in resulting lower its responsive temperature compared with dry membrane. The mechanism of shape memory PCL/PEO hybrid membrane at wet condition has been proposed.
53 citations
TL;DR: In this article, the constitutive relation under different hyperelastic models (Gent and neo-Hookean model) was analyzed based on both theoretical and experimental study, and the allowable areas in force-displacement and voltage-charge plane according to different failure modes, and then calculated the maximal energy density in one energy harvesting period.
Abstract: Dielectric elastomer (DE) is a smart soft material. It is able to produce large deformation under mechanical force and electric field, so that it can achieve mutual conversion between mechanical energy and electrical energy. Based on this property, dielectric elastomer can be used in energy harvesting field. In this paper, firstly, we analyzed the constitutive relation under different hyperelastic models (Gent and neo-Hookean model) based on both theoretical and experimental study. Secondly, we depicted the allowable areas in force-displacement and voltage-charge plane according to different failure modes, and then calculated the maximal energy density in one energy harvesting period. Thirdly, we studied the viscoelastic energy dissipation which can lose the input mechanical energy in the energy harvesting process. Finally, we designed and fabricated a wave power generator, and tested its performance. This paper is of deep significance to the future applications of DE generators.
46 citations
TL;DR: In this article, an intelligent algorithm based on backpropagation artificial neural network for the acoustic emission source localization was developed with the established and trained methods of the algorithm were stated with the time difference of arrival detected by a fiber optic acoustic emission sensor array and the coordinates of acoustic source.
Abstract: An intelligent algorithm was developed based on backpropagation artificial neural network for the acoustic emission source localization. The established and trained methods of the algorithm were stated with the time difference of arrival detected by a fiber optic acoustic emission sensor array and the coordinates of acoustic emission source. The response characteristic of fiber optic acoustic emission sensor was calibrated with the commercial piezoelectric ceramic transducer (PZT) acoustic emission sensor, which provided that the fiber optic acoustic emission sensor was better suited to detect the low frequency of stress wave than the PZT sensor. Four fiber optic acoustic emission sensors were deployed in a square array in an aluminum plate for comparisons between different algorithms of source localization. Comparison results of acoustic emission source location provided that the intelligent algorithm improved the accuracy by reducing the nonlinear errors. For the anisotropic materials, a sensor array de...
37 citations
TL;DR: A polymer matrix composite is a brittle material, and local fibre, matrix fracture and bonding delamination will cause the catastrophic failure of the composite as discussed by the authors, so, the strain and damage st...
Abstract: Advanced polymer matrix composite is a brittle material, and local fibre, matrix fracture and bonding delamination will cause the catastrophic failure of the composite. So, the strain and damage st...
TL;DR: In this paper, a shape memory polymer composite cylinder (thin-walled tube) was designed based on three different deformation ways of the cylinder, and the deformation models were analyzed to verify the feasibility of the smart release devices.
TL;DR: In this article, a thermosetting epoxy-based shape memory composite microfibers are successfully fabricated by means of coaxial electrospinning, in which epoxy as the core layer is for an enhancing purpose.
Abstract: The thermosetting epoxy-based shape memory composite microfibers are successfully fabricated by means of coaxial electrospinning. The PCL/epoxy composite fiber shows core/shell structure, in which epoxy as the core layer is for an enhancing purpose. By incorporating epoxy and PCL, the mechanical strength of composite fibers is greatly reinforced. The deformation is via the heating and cooling process, and the shape memory effect can be demonstrated from the micro level to the macro level. The whole shape recovery performance takes only 6.2 s when triggered by the temperature being at 70 °C. The porosity of woven microfibers changes in response to temperature. In addition, the PCL/epoxy composite microfiber membranes are analyzed in an in vitro cytotoxicity test, which proves that PCL as the shell layer provides the composite microfibers potential capabilities in biomedical science.
TL;DR: Guo et al. as discussed by the authors investigated the influence of strain rate and temperature on the mechanical behavior of shape memory polymers, in particular on the post yield stresses and the strain hardening behavior.
Abstract: In the last few decades, shape memory polymers have demonstrated their major advantages of extremely high recovery strain, low density and low cost. Generally, the mechanical behavior of shape memory polymers is strongly dependent on the loading strain rates. Uniaxial tensile experiments were conducted on one kind of typical shape memory polymer (epoxy) at several different temperatures (348 K, 358 K, 368 K and 378 K) and true strain rates (0.25% s−1, 1.25% s−1 and 2.5% s−1). Thus, the influence of strain rate and temperature on the mechanical behavior of epoxy, in particular on the post yield stresses and the strain hardening behavior, were investigated through this experimental study. Based on our previous work Guo (2014 Smart Mater. Struct. 23 105019), a simplified model which can explain the shape memory effect of epoxy was proposed to predict the strain hardening behavior of the shape memory polymer. Based on the suggestion of Rault (1998 J. Non-Cryst. Solids 235–7 737–41), a linear compensation model was introduced to indicate the change in yield stresses with the increase of strain rate and temperature. Finally, the new model predictions for the true strain and stress behavior of epoxy were compared with the experimental results.
TL;DR: In this article, a new kind of deployable morphing structure based on shape memory polymer (SMP), which can overcome the drawbacks of traditional deployable morphhing structures, such as unavoidable system impact, unsatisfied deformation accuracy and complex mechanical masses, is proposed.
Abstract: Purpose – This study aims to propose a new kind of deployable morphing structure based on shape memory polymer (SMP), which can overcome the drawbacks of traditional deployable morphing structures, such as unavoidable system impact, unsatisfied deformation accuracy and complex mechanical masses. Design/methodology/approach – In this study, although the deployment of the morphing structure was still driven by the specially designed mechanical structures, the application of SMP material realized a steady and accurate deploying process. Besides, SMP material was also utilized as the wing’s filler. During its shape recovery process, the internal SMP filler helps to form an aerofoil for the wing to sustain the surface aerodynamic loads. Findings – Primary experiments were also completed to demonstrate the feasibility and the controllability of the designed deployable morphing structure, including the deploying velocity of the SMP filler and morphing structure. Finally, the wing’s deformation under the air load...
TL;DR: In this article, a shape memory polymer (SMP) mandrel is used to verify the shape recovery and extraction characteristics for the manufacturing of composite structures with complex and ducted forms.
TL;DR: In this article, the authors proposed a design of DEMES that has larger torque than the traditional design with the same number of layers of dielectric elastomer actuators.
Abstract: The dielectric elastomer minimum energy structure (DEMES) can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer (DE), so it is a suitable candidate to make a rotary joint for a soft robot. However, the payload capacity of a DEMES joint is small compared with other types of dielectric elastomer actuators. Stacking layers of pre-strained DE thin films can increase the output torque of DEMES, but greater driving power will be needed, limiting application in mobile or flying soft robots. In this paper, based on static analysis, a design of DEMES is proposed that has larger torque than the traditional design with the same number of layers of dielectric elastomer. As an experimental example, the torque of the film with the improved design is larger than 1.7 times that of the traditional design. Experiments validate the theoretical analysis and demonstrate the improvement of DEMES output torque.
TL;DR: In this paper, the SMA-elastomer composites were experimentally proved to be effective and theoretically investigated, by changing the environment temperature from M s to A f, by which the grains of SMA wires could be switched from martensitic phase to austenitic phase.
TL;DR: In this article, a 10% weight fraction of copper (II) chloride (CuCl2) was embedded into shape memory polyurethane (SMPU) by dissolving it in a solvent mixture of tetrahydrofuran and N,N-dimethyl formamide.
Abstract: In this study, 10% weight fraction of copper (II) chloride (CuCl2) was embedded into shape memory polyurethane (SMPU) by dissolving it in a solvent mixture of tetrahydrofuran and N,N-dimethyl formamide. It is found that CuCl2 particles migrate; they are released from the polymer in the water-driven shape recovery process of SMPU composites. SMPU composites, after various immersion times in water, were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Experimental results support that hydrogen bonding between polyurethane macromolecules and water molecules is the driving force, resulting from the inductive decrease in the glass transition temperature. Furthermore, the release of the stored mechanical energy in SMPU is demonstrated by means of tracking the migration of CuCl2 particles via x-ray diffraction and scanning electron microscopy tests. This study focuses on the mechanism of release of the stored mechanical energy of a polymer, which is identified as the driving force for the chemo-responsive shape memory effect and inductive decrease in glass transition temperature of SMPU in response to the water.
TL;DR: In this article, a thermodynamic model is presented to investigate the stability of MWCNT particle-doped dielectric elastomer composites, and the results show that the permittivity can be significantly improved with the addition of conductive particles.
Abstract: Experiments are conducted to test the permittivity of dielectric elastomer composites adulterated with multi-walled carbon nanotube (MWCNT). The results show that the permittivity of dielectric elastomer composites can be significantly improved by adding MWCNT conductive particles. A thermodynamic model is presented to investigate the stability of MWCNT particle-doped dielectric elastomer composites. The theoretical investigation proves that the polarization of MWCNT, the electrostriction deformation and material constants of the elastomer significantly affect the stability of the thermodynamic system. The numerical analysis shows that comparing to ideal dielectric elastomer, the stability of dielectric elastomer composites filled with MWCNT coupling between electrostriction and polarization can be significantly enhanced.
TL;DR: In this paper, the shape memory effects of nano-ZnO particles inside styrene-based and epoxy-based SMPs and EPSMPs were investigated under UVA degradation test.
TL;DR: An effective resistive Joule heating approach was conducted to improve the electrical actuation and shape-recovery performance of a shape memory polymer (SMP) nanocomposite as discussed by the authors.
Abstract: An effective resistive Joule heating approach was conducted to improve the electrical actuation and shape-recovery performance of a shape memory polymer (SMP) nanocomposite. Two types of gold (Au) film patterns were deposited to be used as electrodes to drive thermal-responsive SMPs and achieve a uniform temperature distribution during electro-activated shape recovery. Furthermore, the sensing capability of the Au electrode to both mechanical and thermal stimuli applied to the SMP nanocomposite was experimentally investigated and theoretically analyzed. It was found that the change in the electrical resistance of the Au electrode could be used as an indication of shape-recovery performance. The linear response of the electrical resistance to strain was identified mainly due to the opening/closing of microcracks and their propagations in the Au electrodes during out-of-plane deformations. With an increment of thermomechanical bending cycles, the electrical resistance was increased exponentially, but it returned back to the original reading when the SMP nanocomposite returned back to its permanent shape. Finally, the flexible Au electrode enabled the actuation of the SMP nanocomposite under an electric voltage of 13.4 V, with an improved shape-recovery performance and temperature distribution.
TL;DR: In this article, electrospun chitosan (CS) blends with various contents of poly(ethylene oxide) (PEO) into a series of composite nanofibrous membranes exhibiting shape-memory behaviors.
Abstract: With aim of constructing a class of functional environmentally friendly materials, we electrospun chitosan (CS) blends with various contents of poly(ethylene oxide) (PEO) into a series of composite nanofibrous membranes exhibiting shape-memory behaviors. In the present composite system, CS and PEO served as hard and soft domains, respectively. The CS, presenting no thermal transition, and the PEO, with apparent melting–crystallization, were demonstrated by differential scanning calorimetry testing. Characterizations also revealed that the morphologies of the CS/PEO membranes were controlled by the mass ratios of CS/PEO. The composite fibrous membranes showed great mechanical performances and thermal stabilities as well. Moreover, CS/PEO possessed excellent shape-memory behaviors. Such fibrous membranes could complete their shape-recovery processes within 20 s at the temperature of 20°C above the melting transition temperature (Tm). Both the shape fixity and shape-recovery ratios were higher than 90%, even after five cycles. The CS/PEO fibrous membranes present significant potential applications in the field of biotechnology and tissue engineering, such as in scaffolds and smart tubes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42532.
TL;DR: A new way to fabricate thin flat lens using laser directed patterning of carbon nanotubes-based buckypaper for producing a diffractive optical device is exploited.
Abstract: Laser directed patterning of carbon nanotubes-based buckypaper for producing a diffractive optical device is presented here. Using a laser ablation method the buckypaper was patterned into a binary Fresnel zone plate lens. Computational modelling was performed which revealed excellent focusing performance of the lens for both visible and THz radiations. SEM and Raman measurements of the lens were studied to analyse the laser–material interaction. The focusing properties of the lens were characterized and a good agreement with the simulations was achieved. Hence, we exploited a new way to fabricate thin flat lens. The one-step fabrication process is economical, convenient and has great potential for industrial scale up.
TL;DR: In this article, the synergistic effect of self-assembled carbon nanofiber nanopaper and hexagonal boron nitrides on the electrical and thermal properties and the electro-activated shape recovery behavior of shape memory polymer nanocomposites was studied.
Abstract: This work studies the synergistic effect of self-assembled carbon nanofiber nanopaper and hexagonal boron nitrides on the electrical and thermal properties and the electro-activated shape recovery behavior of shape memory polymer nanocomposites. The combination of the carbon nanofiber nanopaper and hexagonal boron nitrides results in improved electrical and thermal conductivities of the shape memory polymer nanocomposites. The carbon nanofiber nanopaper was coated on the surface of the shape memory polymer nanocomposite in order to achieve the shape recovery induced by electrical Joule heating. The hexagonal boron nitrides were blended into the shape memory polymer resin to improve the thermal conductivity and decrease their thermal dissimilarity with carbon nanofiber nanopaper, which enhanced the heat transfer from the nanopaper to the underlying shape memory polymer nanocomposite to accelerate the actuation.
19 May 2015
TL;DR: In this paper, the authors make a brief review of dielectric elastomer and its applications and then make a outlook on the research of Soft Dielectric Electroactive Elastomer (SDEEL).
Abstract: Dielectric elastomer has special mechanical and electrical performance It can change its shape or volume under external electric field and can recover the original shape or volume when the electric field is removed That makes it one of the most promising electroactive polymers for fabricating actuators, sensors, shakers and energy harvesters and have huge application potential in areas such as artificial muscle, intelligent biomimetics, aerospace, mechanics and biology This paper make a brief review of dielectric elastomer and its applications firs and then focuses on the progress in dielectric elastomer theories, including constitutive theory, electromechanical stability, snap-through stability, giant electrostriction mechanism, allowable area description and failure analysis of dielectric devices At last, this paper make a outlook on the research of soft dielectric electroactive elastomer
TL;DR: In this article, the free energy of the dielectric elastomer electrical-mechanical coupling system and its constitutive relation and stability behavior were investigated and the critical deformation suffering from the voltage was calculated.
Abstract: Dielectric elastomer is a kind of typical electro-active polymer material. Under external electric field it can produce large electrostriction deformation and possesses the advantages of high elastic energy density, super short response time, high efficiency, and so on. It is widely used in the artificial muscles, facial expressions, actuators, energy harvesters, sensors, robots and Braille display devices, and also shows huge application potential in the aerospace and intelligent bionic areas. We built the free energy of the dielectric elastomer electrical-mechanical coupling system and investigated its constitutive relation and stability behavior. Then we calculated the elastomer’s critical deformation suffering from the voltage. If electrical breakdown, electromechanical instability and snap-through instability can be avoided, the large electrostriction deformation can induce adiabatic temperature change and isothermal entropy change of the dielectric elastomer. We used the entropy-temperature or electric displacement-electric field plane to describe the temperature change and entropy change of dielectric elastomer undergoing large electrostriction deformation. With the influence of temperature, we developed a temperature and deformation coupling thermodynamical free energy model to calculate the electric field induced variation of temperature and entropy in dielectric elastomers. The results should offer great help in guiding the design and fabrication of excellent actuators featuring soft dielectric elastomers.
TL;DR: In this paper, a multi-functional carbon nanotube paper was fabricated successfully by using commercial carbon-notube and tested by infrared camera with deicing time less than 220s and 450s to melt a certain amount of ice under different ambient condition.
Abstract: Carbon nanotube paper (CNP) based multi-functional composite material is an attractive candidate for deicing, flame retardancy, thermal insulation and lighting strike protection due to the excellent conductivity, light weight and thin dimensions. In this article, multi-functional carbon nanotube paper was fabricated successfully by using commercial carbon nanotube. As a deicing composite material, carbon nanotube was used directly without pretreatment in fabricating carbon nanotube paper. The conductivities of the carbon nanotube paper and deicing composite were 77.8S/cm and 64.9S/ respectively. Electrical heating and deicing performance were test by infrared camera with deicing time less than 220s and 450s to melt a certain amount of ice under different ambient condition. CNT was grafted by zirconium (IV) butoxide solution and dimethyl dichlorosilicane to form co-oligomers on the tube surface while oligomers decompose under a certain temperature to develop an inorganic layer of silicon zirconium oxide. The oxidizing temperature of carbon nanotube increases more than 20°C and the weight loss rate decreases 20% than the untreated carbon nanotube. Lightning protection material required high electro conductivity, due to the utmost high current in a short time. Therefore, silver nanoparticles were deposited on the surface of carbon nanotube with the diameter around 100nm. The conductivity increased sharply from 84s/cm to1756s/cm with the mount of 5.9wt% Ag of the modified carbon nanotube paper because the silver nanoparticles deposited on the surface. In addition, the silver modified also can be used as thermal insulation material decreasing the infrared radiation.
TL;DR: In this article, a suitable solvent system for use in electrospinning of silica-based inorganic/organic hybrid membranes with tunable performance was successfully conducted, and the flexibility of the silica/hexamethylene diisocyanate hybrid membrane was demonstrated and hydrophobic behavior with separation characteristics was confirmed for the polymethyl methacrylate hybrid membrane.
Abstract: In order to explore and develop the exceptional performance of inorganic/organic hybrid materials, research into a suitable solvent system for use in electrospinning of silica-based inorganic/organic hybrid membranes with tunable performance was successfully conducted. Hexamethylene diisocyanate and polymethyl methacrylate were selected specifically on the basis of their characteristic features to be combined with inorganic silica gel in different solvents. Excellent flexibility of the silica/hexamethylene diisocyanate hybrid membrane was demonstrated and hydrophobic behavior with separation characteristics was confirmed for the silica/polymethyl methacrylate hybrid membrane.
TL;DR: In this paper, a comparison of strain measurements observed from FBG sensors embedded in a composite plate sample at a closer location to a void and full field thermo-elastic stress map is presented.
Abstract: Monitoring internal damage status of advanced composite components with distributed sensor network has shown significant success in recent research works. However, application of such a system in a full scale structure is a critically challenging task and maintaining such a system during life time operations is an extremely difficult. An additional non-contactable full field strain measurement system being used to measure outer surface strain field of a composite sample while an embedded FBG sensor closer to an internal void being used to monitor localized strain variation. Recent developments in miniature low-cost microbolometer technology have paved the way to use full field thermo-elastic stress mapping using relatively inexpensive Infra-Red cameras. This paper details a comparison of strain measurements observed from FBG sensors embedded in a composite plate sample at a closer location to a void and full field thermo-elastic stress map. The test coupons were fabricated with a purposely created delamination and sample was loaded by quasi-static and low cycle fatigue uni-axial loads. The FBG responses and IR images were recorded in frequent intervals in order to track the delamination growth. Further the strain variations were studied using a detailed FEA and compared with experimental strain and full field Thermo-elastic stress map. doi: 10.12783/SHM2015/82