纤维自动铺放工艺（AFP）制备罐外固化（OOA）复合材料中难以避免出现铺放缺陷如缝隙（Gaps），影响复合材料的力学和疲劳性能。选取罐外固化预浸料IM7/CYCOM5320-1，采用自动铺放工艺制备正常（NDS）和预置缺陷（DS）复合材料，探讨了铺放缺陷对0°单向罐外固化复合材料拉-拉疲劳性能的影响，建立了疲劳寿命和剩余强度衰减模型。结果表明，相比于NDS罐外固化复合材料，DS的静态拉伸强度降低5.90%，拉伸模量降低6.54%；NDS和DS复合材料的疲劳寿命均随疲劳载荷的增大而减少，DS的疲劳寿命一直低于NDS；随着疲劳载荷的增加，二者的疲劳寿命相差越大，铺放缺陷的影响也越来越明显；NDS和DS复合材料在拉-拉疲劳测试前期的力学强度均维持平稳状态，达到一定疲劳周数后力学强度明显下降；应力水平越高，铺放缺陷对罐外固化复合材料的剩余强度影响越明显，而不同应力比下，缺陷对剩余强度的影响一致。
In manufacturing of Out-of-Autoclave (OOA) composites based on Automated Fiber Placement (AFP), it is inevitable to have defects such as gaps, which will affect the mechanical and fatigue properties of the final parts. In this work, out-of-autoclave prepregs IM7/CYCOM5320-1 are selected, Non Defective Samples (NDS) and Defective Samples (DS) are manufactured by automated fiber placement process. The influence of defects on the tension-tension fatigue behavior of 0° unidirectional out-of-autoclave composites is investigated. The fatigue life model and the residual strength degradation model are developed. The results reveal that due to laying defects, the static tensile strength of the composite decreased by 5.90%, and the tensile modulus decreased by 6.54%. As the fatigue load increases, the fatigue life of both non defective and defective composites shows a downward trend, while the fatigue life of the defective composite is always less than that of the non defective one. The longer the fatigue life is, the more differences are there between non defective and defective composites. Meanwhile, the influence of defects also increases with the fatigue life. In the investigation of the residual strength, both non defective and defective composites exhibit a constant behavior at the beginning of tension-tension fatigue tests, followed by a dramatical drop at specific fatigue cycles. Considering the influence of defects on residual strength of composites, the higher the stress level is, the more obvious the effect becomes. However, defects exhibit a similar influence on residual strength when the stress ratio is different.
[1] 李阳, 肇研, 刘刚, 等. 国产CCF300碳纤维及其NCF织物的性能[J]. 航空学报, 2014, 35(10):2889-2900. LI Y, ZHAO Y, LIU G, et al. Properties of domestic CCF300 carbon fiber and its NCP fabrics[J]. Acta Aeronautica et Astronautica Sinica, 2014, 35(10):2889-2900(in Chinese).[2] CAMPBELL F C. Manufacturing technology for aerospace structural materials[M]. London:Elsevier, 2011.[3] GARDINER G. Out-of-autoclave prepregs:Hype or revolution?[J]. High-Performance Composites, 2011(19):32-39.[4] CENTEA T, HUBERT P. Out-of-autoclave prepreg consolidation under deficient pressure conditions[J]. Journal of Composite Materials, 2014, 48(16):2033-2045.[5] KOON R W, PARSONS S C, POVLITZ K A, et al. Out-of-autoclave fiber placement developments[J]. SAMPE Journal, 2016, 52(4):28-40.[6] CROFT K, LESSARD L, PASINI D, et al. Experimental study of the effect of automated fiber placement induced defects on performance of composite laminates[J]. Composites Part A:Applied Science and Manufacturing, 2011, 42(5):484-491.[7] BLOM A W, LOPES C S, KROMWIJK P J, et al. A theoretical model to study the influence of tow-drop areas on the stiffness and strength of variable-stiffness laminates[J]. Journal of Composite Materials, 2009, 43(5):403-425.[8] HSIAO H M, DANIEL I M. Effect of fiber waviness on stiffness and strength reduction of unidirectional composites under compressive loading[J]. Composites Science and Technology, 1996, 56:581-593.[9] COLOMBO C, VERGANI L. Influence of delamination on fatigue properties of a fibreglass composite[J]. Composite Structures, 2014, 107:325-333.[10] BUTLER S, GURVICH M, GHOSHAL A, et al. Effect of embedded sensors on interlaminar damage in composite structures[J]. Journal of Intelligent Material Systems and Structures, 2011, 22(16):1857-1868.[11] BATHIAS C. An engineering point of view about fatigue of polymer matrix composite materials[J]. International Journal of Fatigue, 2006, 28(10):1094-1099.[12] 王军, 程小全, 张纪奎, 等. T700复合材料层合板拉-拉疲劳性能[J]. 航空材料学报, 2012, 32(3):85-90. WANG J, CHENG X Q, ZHANG J K, et al. Study on tension-tension fatigue properties of T700 composite laminates[J]. Journal of Aeronautical Materials, 2012, 32(3):85-90(in Chinese).[13] KAWAI M, MATSUDA Y, YOSHIMURA R. A general method for predicting temperature-dependent anisomorphic constant fatigue life diagram for a quasi-isotropic woven fabric carbon/epoxy laminate[J]. Composites Part A:Applied Science and Manufacturing, 2012, 43(6):915-925.[14] ASTM. Standard test method for tensile properties of polymer matrix composite materials:D3039/D3039M-14[S]. 2014.[15] ASTM. Standard test method for tension-tension fatigue of polymer matrix composite materials:D3479/D3479M-12[S]. 2012.[16] LAN M, CARTIE D, DAVIES P, et al. Microstructure and tensile properties of carbon-epoxy laminates produced by automated fibre placement:Influence of a caul plate on the effects of gap and overlap embedded defects[J]. Composites Part A:Applied Science and Manufacturing, 2015, 78:124-134.[17] MAKEEV A, NIKISHKOV Y, SEON G, et al. Effects of defects of interlaminar performance of composites[C]//Proceedings of the 39th European Rotorcraft Forum, 2013:3-6.[18] GIANCANE S, PANELLA F W, DATTOMA V. Characterization of fatigue damage in long fiber epoxy composite laminates[J]. International Journal of Fatigue, 2010, 32(1):46-53.[19] SHOKRIEH M M, LESSARD L B. Progressive fatigue damage modeling of composite materials, Part Ⅱ:Material characterization and model verification[J]. Journal of Composite Materials, 2000, 34(13):1081-1116.[20] SHOKRIEH M M, LESSARD L B. Multiaxial fatigue behaviour of unidirectional plies based on uniaxial fatigue experiments-Ⅰ. Modelling[J]. International Journal of Fatigue, 1997, 19(3):201-207.[21] GATHERCOLE N, REITER H, ADAM T, et al. Life prediction for fatigue of T800/5245 carbon-fibre composites:Ⅰ. Constant-amplitude loading[J]. International Journal of Fatigue, 1994, 16(8):523-532.[22] TOUBAL L, KARAMA M, LORRAIN B. Damage evolution and infrared thermography in woven composite laminates under fatigue loading[J]. International Journal of Fatigue, 2006, 28(12):1867-1872.[23] WEI B S, JOHNSON S, HAJ-ALI R. A stochastic fatigue damage method for composite materials based on Markov chains and infrared thermography[J]. International Journal of Fatigue, 2010, 32(2):350-360.[24] KAWAI M, YANO K. Probabilistic anisomorphic constant fatigue life diagram approach for prediction of P-S-N curves for woven carbon/epoxy laminates at any stress ratio[J]. Composites Part A:Applied Science and Manufacturing, 2016, 80:244-258.[25] SHOKRIEH M M, LESSARD L B. Multiaxial fatigue behaviour of unidirectional plies based on uniaxial fatigue experiments-Ⅱ. Experimental evaluation[J]. International Journal of Fatigue, 1997, 19(3):209-217.[26] VAN P W, DEGRIECK J. New coupled approach of residual stiffness and strength for fatigue of fibre-reinforced composite[J]. International Journal of Fatigue, 2002, 24(7):747-762.[27] SHOKRIEH M M. Progressive fatigue damage modeling of composite materials[D]. Monterey:McGill University, 1996.[28] TOUBAL L, KARAMA M, LORRAIN B. Damage evolution and infrared thermography in woven composite laminates under fatigue loading[J]. International Journal of Fatigue, 2006, 28(12):1867-1872.[29] PASSIPOULARIDIS V A, PHILIPPIDIS T P. Strength degradation due to fatigue in fiber dominated glass/epoxy composites:a statistical approach[J]. Journal of Composite Materials, 2009, 43(9):997-1013.[30] TALREJA R. Multi-scale modeling in damage mechanics of composite materials[J]. Journal of Materials and Science, 2006, 41(20):6800-6812.[31] GIANCANE S, PANELLA F W, DATTOMA V. Characterization of fatigue damage in long fiber epoxy composite laminates[J]. International Journal of Fatigue, 2010, 32(1):46-53.
CJA