The crack tip element method is applied to the formulation of energy release rates associated with face sheet debonding of sandwich beams with residual thermal stresses using the bi-layer Timoshenko beam model. Special attention is paid to the energy release rates of DCB and MMB tests for debond characterization. Mode-I and mode-II energy release rates are formulated including residual thermal stresses. The derived analytical results are verified by comparison with finite element analysis. The effect of residual thermal stresses on the evaluated apparent fracture toughness, resulting from the neglect of residual thermal stresses in the standard evaluation methods, is discussed.
Herrmann A., Zahlen PC and Zuardy I.Sandwich structures technology in commercial aviation. In: Proceedings of the 7th International Conference on Sandwich Structures . Aalborg, Denmark, 2006, 13-26.
2.
Carlsson LA, Sendlein LS and Merry SLCharacterization of face/core shear fracture of composite sandwich beams. J Compos Mater1991; 25: 101-116.
3.
Nokkentved A. , Lundsgaard-larsen C. and Berggreen C.Non-uniform compressive strength of debonded sandwich panels - I. experimental investigation . J Sandwich Struct Mater2005; 7: 461-482.
4.
Gates TS, Su X., Abdi F., Odegard GM and Herring HMFacesheet delamination of composite sandwich materials at cryogenic temperatures . Compos Sci Technol2006; 66: 2423-2435.
5.
Charalambides PG, Lund J., Evans AG and McMeeking RMA test specimen for determining the fracture resistance of bimaterial interfaces. J Appl Mech1989; 56: 77-82.
6.
Wang JS and Suo Z.Experimental determination of interfacial toughness using brazil-nut-sandwich . Acta Metall Mater1990; 38: 1279-1290.
7.
Schapery RA and Davidson BDPrediction of energy release rate for mixed-mode delamination using classical plate theory. Appl Mech Rev1990; 43: S281-S287.
8.
Hutchinson JW and Suo Z.Mixed mode cracking in layered materials. Adv Appl Mech1992; 29: 63-191.
9.
Alif N., Carlsson LA and Gillespie JrJW.Mode I, Mode II, and mixed mode interlaminar fracture of woven fabric carbon/epoxy. ASTM STP1997; 1242: 82-106.
10.
Pereira AB and de Morais ABMixed Mode I + II interlaminar fracture of carbon/epoxy laminates. Compos PartA2008; 39: 322-333.
11.
ASTM D5528. Test method for mode I interlaminar fracture toughness of unidirectional fiber-reinforced polymer matrix composites. West Conshohocken: American Society for Testing and Materials, 2006.
12.
JIS K7086. Testing methods for interlaminar fracture toughness of carbon fibre reinforced plastics. Tokyo: Japanese Standards Association, 2004.
13.
ASTM D6671. Test method for mixed mode i-mode ii interlaminar fracture toughness of unidirectional fiber reinforced polymer matrix composites. West Conshohocken: American Society for Testing and Materials, 2006.
14.
Aviles F. and Carlsson LAAnalysis of the sandwich DCB specimen for debond characterization. Eng Fract Mech2008; 75: 153-168.
15.
Quispitua A., Berggreen C. and Carlsson LAOn the analysis of a mixed mode bending sandwich specimen for debond fracture characterization. Eng Fract Mech2009; 76: 594-613.
16.
Jiao J., Gurumurthy CK, Kramer EJ, Sha Y., Hui CY and Borgesen P.Measurement of interfacial fracture toughness under combined mechanical and thermal stresses. J Electron Packag1998; 120: 349-353.
17.
Nairn JAEnergy release rate analysis for adhesive and laminate double cantilever beam specimens emphasizing the effect of residual stresses. Int J Adhes Adhes2000; 20: 59-70.
18.
Nairn JAOn the calculation of energy release rates for cracked laminates with residual stresses. Int J Fract2006; 139: 267-293.
19.
Yokozeki T. , Ogasawara T. and Aoki T.Correction method for evaluation of interfacial fracture toughness of dcb, enf and mmb specimens with residual thermal stresses . Compos Sci Technol2008; 68: 760-767.
20.
Yokozeki T.Energy release rates of bi-material interface crack including residual thermal stresses: application of crack tip element method. Eng Fract Mech2010; 77: 84-93.
21.
Davidson BD , Hu H. and Schapery R.An analytical crack-tip element for layered elastic structures. J Appl Mech1995; 62: 294-305.
22.
Wang J. and Qiao P.On the energy release rate and mode mix of delaminated shear deformable composite plates. Int J Solids Struct2004; 41: 2757-2779.
23.
Wang J. and Qiao P.Mechanics of bimaterial interface: shear deformable split bilayer beam theory and fracture. J Appl Mech2005; 72: 674-682.
24.
Suo Z. and Hutchinson JWInterface crack between two elastic layers. Int J Fract1990; 43: 1-18.
25.
Carlsson LA , Matteson RC, Aviles F. and Loup DCCrack path in foam cored dcb sandwich fracture specimens. Compos Sci Technol2005; 65: 2612-2621.
26.
Ramantani DA , de Moura Mfsf, Campilho Rdsg and Marques ATFracture characterization of sandwich structures interfaces under mode I loading. Compos Sci Technol2010; 70: 1386-1394.
27.
Rinker M., John M. and Schäuble W.Untersuchungen zur Schadenstoleranz von CFK-Schaum-Sandwichstrukturen mit Hilfe von DCB- und ENF-Tests. In: Proceedings of the 2010 German Congress on Aeronautics and Astronautics, Hamburg, Germany, 2010, 211-220 (in German).
