Bonded repair was conducted to composite sandwich panels with one side skin and full-depth core penetrated damage. Experiments on edgewise compressive behavior of repaired panel were carried out and influences of various repair parameters including different repair materials (high or medium temperature cured pre-preg), different taper ratios for scarf repair (1/30 or 1/10) and different repair techniques (scarf or step repair) were compared. Based on continuum damage mechanics, a three-dimensional finite element model was developed and a good agreement of experimental results with numerical predictions was obtained. With the analysis model, ultimate loads, damage evolution processes and adhesive stress distributions of repaired sandwich panels were investigated. The results of this study have provided an insight into the mechanical performance of repaired sandwich panels under edgewise compressive load, which could lead to improved design and analysis methodologies on the bonded repair of composite sandwich structures.
Boeing Ltd. Boeing 737-800 Structural Repair Manual, November 2006.
2.
Airbus Ltd. Airbus A320 Structural Repair Manual, February 2007.
3.
Stone RH. Repair techniques for graphite/epoxy structures for commercial transport applications. NAS1-15269, NASA Langley Research Center, January 1983.
4.
Jones JS and Graves SR. Repair techniques for Celion-LARC-160 graphite-polyimide composite structures. NAS1-16448, NASA Langley Research Center, June 1984.
5.
ArmstrongKBBevanLGColeWF II. Care and repair of advanced composites, 2nd ed. Warren dale, PA: SAE International, 2005, pp. 263–265.
FoundMSFriendMJ. Evaluation of CFRP panels with scarf repair patches. Compos Struct1995; 32: 115–122.
8.
GunnionAJHerszbergI. Parametric study of scarf joints in composite structures. Compos Struct2006; 75: 364–376.
9.
BakerAAChesterRJHugoGR. Scarf repairs to highly strained graphite/epoxy structure. Int J adhes adhes1999; 19: 161–171.
10.
WangCHGunnionAJ. On the design methodology of scarf repair to composite laminates. Compos Sci Technol2008; 68: 35–46.
11.
WhittinghamBBakerAAHarmanA. Micrographic studies on adhesively bonded scarf repairs to thick composite aircraft structure. Compos Part A-Appl S2009; 40: 1419–1432.
12.
AveryJLSankarBV. Compressive failure of sandwich beams with debonded face-sheets. J Compos Mater2000; 34: 1176–1199.
13.
HansenI. Compression behavior of FRP sandwich specimen with interface debonded. J Compos Mater1998; 32: 335–360.
14.
WangHChenXHGuoXL. Strength investigation of composite honeycomb structures after repair. Chinese J Aeronaut2001; 22: 270–273.
15.
ChenJY. Predicting progressive delamination of stiffened fibre-composite panel and repaired sandwich panel by decohesion models. J Thermoplast compos2002; 15: 429–442.
16.
MahdiSKinlochAJMatthewsFL. The static mechanical performance of repaired composite sandwich beams: part I – experimental characterization. J Sandw Struct Mater2003; 5: 179–202.
17.
MahdiSKinlochAJMatthewsFL. The static mechanical performance of repaired composite sandwich beams: part II – finite element modeling. J Sandw Struct Mater2003; 5: 267–303.
18.
Tomblin JS, Salah L, Welch JM, et al. Bonded repair of aircraft composite sandwich structures. FAA Technical Report DOT/FAA/AR-03/74, Washington, February 2004. Springfield, Virginia: National Technical Information Service.
19.
Tomblin JS, Lacy T, Smith B, et al. Review of damage tolerance for composite sandwich airframe structures. Final Report DOT/FAA/AR-99/49, Washington, August, 1999. Springfield, Virginia: National Technical Information Service.
20.
Umeco Structural materials Ltd. Material Documentation of MTM44-1/HTS(12K) prepreg, August, 2009.
21.
Cytec Industries Inc., Material Documentation of CYCOM7714A/HTA40(12K) prepreg, April, 2007.
22.
Hexcel Corporation, Product Data Documentation of HexWeb HRH-10 aramid fiber/phenolic honeycomb, November, 2007.
23.
Cytec Industries Inc., Material documentation of FM490A Core-splice adhesive, 1995.
24.
Henkel Corporation, Material Documentation of Hysol PL 7000 epoxy film adhesive, March, 2008.
David WS. Progressive failure analysis methodology for laminated composite structures. NASA/TP-1999-209107, NASA Langley Research Center, March 1999.
27.
Wang YQ, Tong MB and Zhu YH, Three dimensional continuum damage mechanics model of progressive failure analysis in fiber-reinforced composite laminates. In: 50th AIAA conference on structures, structural dynamics, and materials, Palm Springs, California, 4-7 May, 2009. American Institute of Aeronautics and Astronautics.
28.
MatzenmillerALublinerLTaylorRL. A constitutive model for anisotropic damage in fiber-composites. Mech Mater1995; 20: 125–152.
29.
MaimiPCamanhoPPMayugoJA. A continuum damage model for composite laminates: Part I – Constitutive model. Mech Mater2007; 39: 897–908.
30.
ABAQUS/CAE Version 6.11. User’s manual, Rhode Island, USA: Hibbitt, Karlsson & Sorensen, Inc., 2011.
31.
BesantZDaviesGAOHitchingsD. Finite element modeling of low velocity impact of composite sandwich panels. Compos Part A-Appl S2001; 32: 1189–1196.
32.
ShamesIHPitarresiJM. Introduction to solid mechanic, 3rd ed. New Jersey: Prentice-Hall, 2000, pp. 263–266.
