Advanced aerospace materials, including fibre-reinforced polymer and ceramic matrix composites, are increasingly being used in critical and demanding applications, challenging not only the current damage prediction, detection and quantification methodologies, but also the residual life of the structure. The main objective of this work consists of developing a new methodology based on different techniques to be applied on structural health monitoring system for impacted composite aeronautic structures. For this, it is necessary to identify, and to localise damage, as well as to calculate the severity of the damage and to predict the residual strength of the composite structure. To achieve these goals, the research methodology should consider three methods: (1) vibration-based method, (2) shearography speckle and (3) flexural after impact. Composite plates, made of epoxy resin reinforced by carbon fibre, are evaluated. First, vibration-based method provides frequency response functions to be analysed by a new metric, which is compared in terms of their capability for damage identification and global location. Afterwards, the extension of impact damage is determined using shearography speckle. This technique has demonstrated great potential for damage detection in composite-laminated structures. A flexure after impact test is used to evaluate its limitations and potentialities as a damage-tolerance technique. The residual flexural strength of damaged specimens is evaluated by quasi-static four-point bending test. A new criterion based on a relationship between damage metric from vibration-based method and flexure after impact analysis is presented and discussed. Finally, it discussed the advantages and limitations of this combination of techniques into the context of structural health monitoring systems.
CucAI.Vibration-based techniques for damage detection and health monitoring of mechanical systems. Master’s Thesis, University of South Carolina, Columbia, SC, 2002.
2.
FarrarCRWordenK.An introduction to structural health monitoring. Philos T Roy Soc A2007; 365: 303–315.
3.
LopesHMRSantosJVASoaresCMM. A numerical-experimental method for damage location based on rotation fields spatial differentiation. Comput Struct2011; 89: 1754–1770.
4.
LiuYNayakS.Structural health monitoring: state of the art and perspectives. JOM2012; 64: 789–792.
5.
GianneoACarboniMGiglioM.Feasibility study of a multi-parameter probability of detection formulation for a Lamb waves–based structural health monitoring approach to light alloy aeronautical plates. Struct Health Monit. Epub ahead of print 8 October 2016. DOI: 10.1177/1475921716670841.
6.
McConnellKGVarotoPS.Vibration testing: theory and practice. 2nd ed.New York: John Wiley & Sons, 1995, p.672.
7.
EwinsDJ.Modal testing: theory, practice and application. 2nd ed.Baldock: Research Studies Press, 2000, p.400.
8.
SalawuO.Detection of structural damage through changes in frequency: a review. Eng Struct1997; 19: 718–723.
ZouYTongLStevenG.Vibration-based model-dependent damage (delamination) identification and health monitoring for composite structures: a review. J Sound Vib2000; 230: 357–378.
11.
CardenEPFanningP.Vibration based condition monitoring: a review. Struct Health Monit2004; 3: 355–377.
12.
MontalvãoDMaiaNRibeiroA.A review of vibration-based structural health monitoring with special emphasis on composite materials. Shock Vib Digest2006; 38: 295–324.
13.
WordenKFarrarCRHaywoodJ. A review of nonlinear dynamics applications to structural health monitoring. Struct Control Hlth2008; 15: 540–567.
14.
FanWQiaoP.Vibration-based damage identification methods: a review and comparative study. Struct Health Monit2011; 10: 83–111.
15.
ChandraSBaraiSV.Experimental investigations and critical observations on the use of modal parameters for structural damage detection. Curr Adv Civil Eng2014; 2: 6–15.
16.
NegruIGillichGRPraisachZI. Natural frequency changes due to damage in composite beams. J Phys Conf Ser2015; 628: 012091.
17.
RytterA.Vibration based inspection of civil engineering structures. PhD Thesis, Aalborg University, Aalborg, 1993.
18.
LeendertzJAButtersJN.An image-shearing speckle-pattern interferometer for measuring bending moments. J Phys E Sci Instrum1974; 6: 1107–1110.
19.
NeumannDB. Comparative holography. In: OSA technical digest, topical meeting on hologram interferometry and speckle metrology, 1980, Paper MB2.
20.
RastogiPK.Comparative holographic interferometry: a nondestructive inspection system for detection of flaws. Exp Mech1985; 25: 325–337.
21.
JacquotP.Speckle interferometry: a review of the principal methods in use for experimental mechanics applications. Strain2008; 44: 57–69.
22.
AmbuRAymerichFGinesuF. Assessment of NDT interferometric techniques for impact damage detection in composite laminates. Compos Sci Technol2006; 66: 199–205.
23.
Araújo dos SantosJVLopesHMRVazM. Damage localization in laminated composite plates using mode shapes measured by pulsed TV holography. Compos Struct2006; 76: 272–281.
24.
GarnierCPastorMLEymaF. The detection of aeronautical defects in situ on composite structures using Non Destructive Testing. Compos Struct2011; 93: 1328–1336.
25.
KimGHongSJhangKY. NDE of low-velocity impact damages in composite laminates using ESPI, digital shearography and ultrasound C-scan techniques. Int J Precis Eng Man2012; 13: 869–876.
26.
LopesHRibeiroJDos SantosJA. Localization of damage in beams using interferometric techniques. In: Proceedings of the 6th European workshop on structural health monitoring, Dresden, Germany, 3–6 July 2012.
27.
LopesHRibeiroJAraújo dos SantosJV.Interferometric techniques in structural damage identification. Shock Vib2012; 19: 835–844.
28.
BalamuruganRMuruganandS.Digital image processing technique in laser speckle pattern interferometer for phase evaluation. Int J Eng Adv Technol2013; 2: 560–562.
29.
FrancisDTatamRPGrovesRM.Shearography technology and applications: a review. Meas Sci Technol2010; 21: 1–29.
30.
SantiusteCSanchez-SaezSBarberoE.Residual flexural strength after low-velocity impact in glass/polyester composite beams. Compos Struct2010; 92: 25–30.
31.
BolotinVVShchugorevVN.Effect of low-velocity impact on the residual strength of composites. Mech Compos Mater1994; 29: 357–364.
32.
PuhuiCZhenSJunyangW.A new method for compression after impact strength prediction of composite laminates. J Compos Mat2002; 36: 589–610.
33.
Sanchez-SaezSBarberoEZaeraR. Compression after impact of thin composite laminates. Compos Sci Technol2005; 65: 1911–1919.
34.
WangSXWuLZMaL.Low-velocity impact and residual tensile strength analysis to carbon fiber composite laminates. Mater Design2010; 31: 118–125.
35.
RivallantSBouvetCHongkarnjanakulN.Failure analysis of CFRP laminates subjected to compression after impact: FE simulation using discrete interface elements. Compos Part A: Appl S2013; 55: 83–93.
36.
RotemA.The strength of laminated composite materials under repeated impact loading. J Compos Tech Res1988; 10: 74–79.
37.
MouritzAPGallagherJGoodwinAA.Flexural strength and interlaminar shear strength of stitched GRP laminates following repeated impacts. Compos Sci Technol1997; 57: 509–522.
38.
AmaroAMReisPNBMouraMFSF. Residual strength after low velocity impact in carbon-epoxy laminates. Mater Sci Forum2006; 514–516: 624–628.
39.
ReyesGSharmaU.Modeling and damage repair of woven thermoplastic composites subjected to low velocity impact. Compos Struct2010; 92: 523–531.
40.
CromerKR.Impact and post-impact response of a composite material to multiple non-coincident impacts. Master’s Thesis, University of Delaware, Newark, DE, 2010.
41.
De MedeirosRLopezHMRGuedesRM. A new approach for SHM system: combination of vibration based method and shearography speckle. In Proceedings of the 5th international symposium on solid mechanics (MecSol2015), Belo Horizonte, Minas Gerais, Brazil, 25–27 May 2015.
42.
De MedeirosRLopezHMRGuedesRM. A new methodology for structural health monitoring applications. Procedia Eng2015; 114: 54–61.
43.
De MedeirosRSartoratoMVandepitteD. A frequency based damage detection in unidirectional composite plates using MFC sensors. J Sound Vib2016; 383: 171–190.
44.
SartoratoMDe MedeirosRVandepitteD. Computational model for supporting SHM systems design: damage identification via numerical analyses. Mech Syst Signal Pr2017; 84: 445–461.
45.
De MedeirosR. Development of a criterion for predicting residual strength of composite structures damaged by impact loading. PhD Thesis, São Carlos School of Engineering, University of São Paulo, São Paulo, 2016.
46.
De MedeirosRTitaSPSVandepitteD. Residual flexural strength criterion for composite plates subjected to low velocity impact. In: Proceedings of the meeting on aeronautical composite materials and structures (MACMS2015), São Carlos, São Paulo, Brazil, 3–4 December 2015.
47.
ASTM D6272-10:2010. Standard test method for flexural properties of unreinforced and reinforced plastics and electrical insulating materials by four point bending.
