An Embedded Fiber Optic Sensor Method for Determining Residual Stresses in Fiber-Reinforced Composite Materials

Published on Oct 1, 1998in Journal of Intelligent Material Systems and Structures2.569
路 DOI :10.1177/1045389X9800901002
Craig M. Lawrence10
Estimated H-index: 10
,
Drew V. Nelson22
Estimated H-index: 22
(Stanford University)
+ 1 AuthorsJay R. Spingarn6
Estimated H-index: 6
(SNL: Sandia National Laboratories)
Sources
Abstract
A method to determine process-induced residual stress in fiber-reinforced composite materials using strain measurements from embedded fiber optic sensors is presented. This method allows non-destructive, real-time determination of residual macrostress in these materials and may be useful for both process monitoring and control. Extrinsic Fabry-Perot interferometer strain sensors were embedded in Hercules AS4/3501-6 graphite/epoxy composite specimens prior to cure. The specimens were cured in a press, and the internal strains and temperatures developed during processing were monitored and recorded. Residual macrostresses were computed from these measurements using a viscoelastic model of the material. The results compare favorably with analytical predictions, previous experimental measurements from a destructive technique, and with measurements of warpage of a non-symmetric laminate.
馃摉 Papers frequently viewed together
1997
References26
Newest
#1Yeong K. Kim (UIUC: University of Illinois at Urbana鈥揅hampaign)H-Index: 6
#2Scott R. White (UIUC: University of Illinois at Urbana鈥揅hampaign)H-Index: 96
In this study the cure-dependent stress relaxation of 3501-6 epoxy resin was analyzed. To formulate the constitutive equations, several stress relaxation tests were performed at different degree of cure states. The master curve and shift function for each degree of cure case were obtained by time-temperature superposition. On the basis of this data, the thermorheologically complex behavior of 3501-6 epoxy resin was modeled. The resin model was then used to formulate the constitutive equations fo...
Source
Fiber optic sensor technology has experienced tremendous growth since its early beginnings in the 1970's with early laboratory demonstrations of fiber optic gyros and acoustic sensors and the introduction of the first commercial intensity and spectrally based sensors. These early efforts were followed by a tremendous growth of interest in the 1980's when the number of workers in the field increased from perhaps a few hundred to thousands. The result was the introduction in the 1990's of the firs...
Source
#1Craig M. Lawrence (Stanford University)H-Index: 10
#2Drew V. Nelson (Stanford University)H-Index: 22
Last. Thomas E. Bennett (SNL: Sandia National Laboratories)H-Index: 5
view all 4 authors...
This paper presents the results of experiments to measure the internal strains and temperatures that are generated in graphite/epoxy composite specimens during processing using embedded fiber optic strain sensors and thermocouples. Measurements of strain and temperature, combined with a computational model, offer the potential for non-destructive, real-time determination of residual stress in composites, and may be useful for process monitoring and control. Extrinsic Fabry-Perot interferometer, ...
Source
Tests were performed to assess the effects of processing conditions and laminate layup on the change in shape (springback). Twelve inch long and one inch wide coupons made of Fiberite T300/976 graphite/epoxy were tested. Coupons of different layups were cured using different types of molds and different types of vacuum bagging arrangements. The curing was performed with different temperature cycles. Springback was measured from the change in shape of initially flat coupons. The results indicated...
Source
The published literature on the effect of optical sensors and fibers embedded in host composite materials is reviewed. The literature indicates that improperly embedded optical fibers produce local distortions and resin-rich regions in the host composite that cause structural performance degradation. This is especially true for compressive loading of relatively thin composite laminates. Tensile strength is at most only slightly degraded. The available data are inconclusive for fatigue loading.
Source
#1Craig M. Lawrence (Stanford University)H-Index: 10
#2Drew V. Nelson (Stanford University)H-Index: 22
This report presents the results of experiments performed to verify the performance of the fiber-optic absolute extrinsic Fabry-Perot interferometer (AEFPI) for strain measurements. In these experiments, AEFPI sensors are surface mounted and embedded in various materials and subjected to mechanical and thermal strains. Strains measured by the AEFPI are compared to analytical predictions and to metallic foil strain gage measurements where possible. The AEFPI sensors and demodulation equipment wer...
Source
#1Yeong K. Kim (UIUC: University of Illinois at Urbana鈥揅hampaign)H-Index: 6
#2Scott R. WhiteH-Index: 96
#1A.J. Fletcher (SHU: Sheffield Hallam University)H-Index: 1
#2J.L. Oakeshott (Imperial College London)H-Index: 1
Abstract Finite element models are developed to predict the thermal residual stresses generated during the processing of carbon fibre/epoxy resin composites. A previous analysis that assumed regular arrays of fibres is extended to include random fibre arrays, which are thought to be more appropriate to the actual fibre distributions. The stresses are local to single fibres under conditions of plane strain. Initially a hypothetical distribution is assumed which is intermediate between a hexagonal...
Source
#1Harold E. Gascoigne (California Polytechnic State University)H-Index: 3
Residual (curing) stresses in a cross-ply laminated plate are related to the strains released when individual plies are separated. Released displacements are determined using high-sensitivity moire interferometry and linearized strain-displacement equations are used to determine residual strains. Elastic orthotropic stress-strain relations are used to calculate residual stresses remote from free-edges of a [9020/020/9020] graphite-epoxy cross-ply panel. The measured strains compare favorably wit...
Source
#1Qing Ma (UCSB: University of California, Santa Barbara)H-Index: 18
#2David R. Clarke (UCSB: University of California, Santa Barbara)H-Index: 107
Abstract The residual stresses in c-axis sapphire fibers in a 纬-TiAl matrix and in a polycrystalline Al2O3 matrix as a function of distance below a surface are determined. They are obtained from the shift in frequency of the characteristic R2 fluorescence line of chromium in sapphire obtained by focusing an optical probe at different depths in a sapphire fiber intersecting the surface of the composite. The method is described together with its calibration. Both the axial and radial components of...
Source
Cited By26
Newest
#1Min FuH-Index: 2
#2Yang YanguangH-Index: 3
Last. Xingcai PiH-Index: 1
view all 5 authors...
In general, conventional resistance strain balances are used to obtain aerodynamics forces in hypersonic wind tunnels. Owing to the advantages of fast response, high sensitivity and anti-electromagnetic interference, fiber optic sensors provide a new technical approach to wind tunnel strain balance. In this paper, a three-component fiber optic balance based on MEMS Fabry-Perot strain sensor has been developed. The MEMS strain sensor based on Fabry-Perot interference was fabricated by surface and...
Source
#1Haixiao HuH-Index: 9
#2Dongfeng CaoH-Index: 7
Last. Shuxin LiH-Index: 17
view all 7 authors...
Abstract Due to the appearance of temperature gradient and non-uniform gelation, fully understanding of residual stresses is even more complex in thick laminates. In this paper, basic mechanisms of cure process were presented firstly. Then, experimental investigation of the non-uniform gelation was carried out together with characterization of necessary material properties. Tailed FBG sets were applied to monitor the cure of thick laminates with temperature gradient. The non-uniform gelation and...
Source
#1Ilaria Poggetti (Marche Polytechnic University)H-Index: 1
#2Jack Dyson (Marche Polytechnic University)H-Index: 4
Last. Valeria Corinaldesi (Marche Polytechnic University)H-Index: 34
view all 7 authors...
The total distributed strain produced during a vacuum-assisted resin infusion moulding composite manufacture process is measured in real time by using optical fibre sensors embedded in three different layers of a thin 5-harness satin weave flat plate cured with low-viscosity epoxy resin/cycloaliphatic polyamine epoxy resin polymer matrix. We present and discuss the chemical reaction of the epoxy resin polymer matrix adhesive to show that under manufacturing conditions, well below the glass trans...
Source
#1Maryam Kahali Moghaddam (University of Bremen)H-Index: 3
#2Mariugenia SalasH-Index: 5
Last. Walter Lang (University of Bremen)H-Index: 48
view all 7 authors...
Source
#1Shu Minakuchi (UTokyo: University of Tokyo)H-Index: 14
This study develops a fiber-optic-based technique for in situ characterization of direction-dependent cure-induced shrinkage in thermoset fiber-reinforced composites. A procedure is established to embed fiber Bragg grating (FBG) sensors in composite out-of-plane directions and to measure key through-thickness chemical cure shrinkage directly under practical curing conditions. First, sensitivity of the proposed method is evaluated through comparison with a standard technique (i.e. thermo-mechanic...
Source
#1Md. Rajibul Islam (UM: University of Malaya)H-Index: 9
#2Muhammad Mahmood Ali (UM: University of Malaya)H-Index: 11
Last. Harith Ahmad (UM: University of Malaya)H-Index: 55
view all 5 authors...
Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometer...
Source
#1M. Safarabadi (UT: University of Tehran)H-Index: 9
#2Mahmood M. Shokrieh (IUST: Iran University of Science and Technology)H-Index: 55
Abstract: This chapter presents a review of the formation and effects of thermal residual stresses, as well as methods of measuring and predicting them. The first part of this chapter focuses on the factors responsible for residual stress formation in composites. The second part discusses the effects of thermal residual stresses on composites and their material properties. After identification of the effective parameters for thermal residual stress build-up and the effects of these stresses on c...
Source
#1Mahmood M. Shokrieh (IUST: Iran University of Science and Technology)H-Index: 55
#2A.R. Ghanei Mohammadi (IUST: Iran University of Science and Technology)H-Index: 3
Abstract: Non-destructive testing (NDT) includes a wide group of techniques utilized in science and industry to evaluate the properties of a material (such as residual stresses) without causing any major damage. Since NDT does not cause any permanent changes in the material being inspected, it is a valuable technique that can save both money and time in evaluation and research. This is why non-destructive tests are often preferred to destructive ones. This chapter discusses the main methods that...
Source
#1M. Lai (EPFL: 脡cole Polytechnique F茅d茅rale de Lausanne)H-Index: 5
#2D. Karalekas (UniPi: University of Piraeus)H-Index: 19
Last. John Botsis (EPFL: 脡cole Polytechnique F茅d茅rale de Lausanne)H-Index: 38
view all 3 authors...
In this paper, a combined experimental-numerical based work was undertaken to investigate the Bragg wavelength shift response of an embedded FBG sensor when subjected to different conditions of multi-axial loading (deformation). The following cases are examined: (a) when an isotropic host material with no constrains on planes normal to the embedded sensor's axis is biaxially loaded, (b) when the same isotropic host material is subjected to hydrostatic pressure and (c) when the hydrostatically lo...
Source
#1Lole褩 Khoun (McGill University)H-Index: 1
#2Rui de Oliveira (EPFL: 脡cole Polytechnique F茅d茅rale de Lausanne)H-Index: 2
Last. Pascal Hubert (McGill University)H-Index: 32
view all 4 authors...
A comprehensive understanding of the development of residual strains in composite processing is essential to manufacture high quality composite parts. In this paper, the use of fibre Bragg grating (FBG) optical sensors was investigated to measure in situ the build-up of the process-induced strains in composite panels manufactured by resin transfer moulding. The FBG sensors, embedded in the composite laminate, successfully measured the evolution of the composite in-plane strains due to the temper...
Source
This website uses cookies.
We use cookies to improve your online experience. By continuing to use our website we assume you agree to the placement of these cookies.
To learn more, you can find in our Privacy Policy.