1、Computational Modeling of the Electromagnetic Characteristics of Carbon Fiber-Reinforced Polymer Composites with Different Weave Structures A.M.Hassana,J.F.Douglasb,and E.J.Garboczia aMaterials and Structural Systems Division,National Institute of Standards and Technology,Gaithersburg,MD 20899,USA b
2、Materials Science and Engineering Division,National Institute of Standards and Technology,Gaithersburg,MD 20899,USA Abstract.Carbon fiber reinforced polymer composites(CFRPC)are of great interest in the aerospace and automotive industries due to their exceptional mechanical properties.Carbon fibers
3、are typically woven and inter-laced perpendicularly in warps and wefts to form a carbon fabric that can be embedded in a binding matrix.The warps and wefts can be interlaced in different patterns called weaving structures.The primary weaving structures are the plain,twill,and satin weaves,which give
4、 different mechanical composite properties.The goal of this work is to computationally investigate the dependence of CFRPC microwave and terahertz electromagnetic characteristics on weave structure.These bands are good candidates for the Nondestructive Evaluation(NDE)of CFRPC since their wavelengths
5、 are comparable to the main weave features.3D full wave electromagnetic simulations of several different weave models have been performed using a finite element(FEM)simulator,which is able to accurately model the complex weave structure.The computational experiments demonstrate that the reflection o
6、f electromagnetic waves from CFRPC depend sensitively on weave structure.The reflection spectra calculated in this work can be used to identify the optimal frequencies for the NDE of each weave structure.Keywords:Carbon Fiber,Twill,Satin,Plain,Terahertz,Microwave,Screening,COMSOL PACS:81.05.Ni,81.05
7、.Lg,81.05.uj,81.70.-q,81.70.Ex INTRODUCTION The global carbon fiber market is expanding rapidly and is expected to almost double,increasing from US$1.8 billion in 2013,to US$3 billion in 2018 1.Carbon fibers are graphite filaments where the carbon atoms are arranged in a crystalline form aligned alo
8、ng the axis of the fiber.Typically,the carbon fibers have diameters ranging from 5 m to 10 m and are grouped into bundles containing thousands of carbon fibers.These bundles are typically woven and inter-laced perpendicularly in warps and wefts to form a carbon fabric that can be embedded in a bindi
9、ng polymer to form carbon fiber-reinforced polymer composites(CFRPC).The weaving structures can be divided into three primary structures termed plain,twill,and satin weaves as shown in Figure 1,as well as many other variations.The weave geometries were generated using the TexGen open source software
10、 2.FIGURE 1.Different weaving structures generated using TexGen 2.PlainTwillSatinwarpweftxy40th Annual Review of Progress in Quantitative Nondestructive EvaluationAIP Conf.Proc.1581,1494-1499(2014);doi:10.1063/1.48649992014 AIP Publishing LLC 978-7354-1211-8/$30.001494 This article is copyrighted as
11、 indicated in the article.Reuse of AIP content is subject to the terms at:http:/scitation.aip.org/termsconditions.Downloaded to IP:202.177.173.189 On:Fri,21 Feb 2014 05:42:44Different weaving structures produce different mechanical properties.For example,a study by Rattan et al.showed that the plain
12、 weave performed best followed by the satin weave and then the twill weave in an erosive wear study performed on CFRPC fabricated using the impregnation technique 3.The goal of this present work is to focus on the electromagnetic(EM)properties of CFRPC to supplement the numerous studies on their mec
13、hanical properties.Recently,the computational modeling of the electromagnetic properties of woven fabric composites has been receiving increasing interest 4-5.Mirotznik et al.used the Rigorous Coupled Wave(RCW)algorithm to predict the EM properties of woven glass fiber composites at frequencies rang
14、ing from DC up to 50 GHz 4.The RCW algorithm was able to predict and explain experimentally detected guided mode resonances from glass fiber composites.The main assumption of the model was that the order did not matter in the regions in Figure 1 where the weft and warp overlap.That is,the region mar
15、ked as x in Figure 1,where the warp is on top of the weft,was considered the same as the region marked as y in Figure 1,where the weft is on top of the warp 4.Therefore,all the overlap regions were modeled with double the thickness of the non-overlapping regions and with dielectric properties equal
16、to the average of the individual dielectric properties of the warps and wefts 4.Wang et al.used the full wave Finite Difference Time Domain(FDTD)to study the properties of CFRPC in a broadband ranging from DC to 2 THz 5.However,the carbon fibers modeled by Wang et al.were non-interlacing 5.In this work,similar to Wang et al.,full wave simulations of CFRPC were performed to investigate their EM properties in a wide range of frequencies,but interlacing carbon fibers were explicitly simulated.Also,
