Effect of hygrothermal environment on mechanical properties and damage mechanism of CFRP
Xu-dong YANG1, Tao AN1, Tian-chun ZOU2,*(), Tian-chen GONG2
1 Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300, China 2 Civil Aircraft Airworthiness Certification Technology and Management Research Center, Civil Aviation University of China, Tianjin 300300, China
The moisture absorption properties of carbon fiber reinforced plastics (CFRP) laminates treated with three kinds of hygrothermal environments (relative humidity 85% RH, temperature 25, 70, 85℃ respectively) were investigated by accelerated moisture absorption method. Tensile, compressive and shear tests were carried out to study the effect of hygrothermal conditions on the mechanical behavior of CFRP laminates. Meanwhile, the damage mechanism of CFRP laminates in hygrothermal environment was analyzed by scanning electron microscopy and infrared spectroscopy. Finally, a formula which could predict the mechanical properties of CFRP laminates in hygrothermal environments was proposed by least square method. The results show that the moisture absorption characteristics of CFRP laminates in preliminary stage accords with Fick's law well. At the same humidity, the CFRP's moisture absorption speeds, the moisture saturation contents and times are increased with the increment of the environmental temperature. The mechanical properties of CFRP laminates in 90°tensile test and shear test are decreased most obviously. Water molecules are associated with epoxy resin through hydrogen bonds after the treatment in hygrothermal environment, however, there is no chemical structure change in the components of the CFRP laminate. The formula of mechanical performance degradation under different hygrothermal conditions is basically consistent with the experimental results.
ZHANG L J , ZHAO Y , LUO Y F , et al. On the interfacial properties of CCF300/QY8911 composite with cyclical hygrothermal treatments[J]. Journal of Materials Engineering, 2012, (2): 25- 29.
KUMAR S B , SRIDHAR I , SIVASHANKER S . Influence of humid environment on the performance of high strength structural carbon fiber composites[J]. Materials Science and Engineering:A, 2008, 498 (1/2): 174- 178.
GENNA S , TROVALUSCI F , TAGLIAFERRI V . Indentation test to study the moisture absorption effect on CFRP composite[J]. Composites Part B:Engineering, 2017, 124, 1- 8.
JIA Z , LI T , CHIANG F , et al. An experimental investigation of the temperature effect on the mechanics of carbon fiber reinforced polymer composites[J]. Composites Science and Technology, 2018, 154, 53- 63.
EFTEKHARI M , FATEMI A . Tensile behavior of thermoplastic composites including temperature, moisture, and hygrothermal effects[J]. Polymer Testing, 2016, 51, 151- 164.
WU Y T , GE D Y , LI C . Dynamic compressive properties of carbon/epoxy composite laminates under hygrothermal environment[J]. Acta Materiae Compositae Sinica, 2016, 33 (2): 259- 264.
ZHONG Y , JOSHI S C . Impact resistance of hygrothermally conditioned composite laminates with different lay-ups[J]. Journal of Composite Materials, 2015, 49 (7): 829- 841.
ZHANG X Y , CAO D , LU F , et al. Aging behavior of T700/5224 composite in hygrothermal environment and chemical media[J]. Journal of Materials Engineering, 2016, 44 (4): 82- 88.
ALMEIDA J H S , SOUZA S D B , BOTELHO E C , et al. Carbon fiber-reinforced epoxy filament-wound composite laminates exposed to hygrothermal conditioning[J]. Journal of Materials Science, 2016, 51 (9): 4697- 4708.
BOTELHO E C , PARDINI L C , REZENDE M C . Hygrothermal effects on the shear properties of carbon fiber/epoxy composites[J]. Journal of Materials Science, 2006, 41 (21): 7111- 7118.
MAGGANA C , PISSIS P . Water sorption and diffusion studies in an epoxy resin system[J]. Journal of Polymer Science Part B:Polymer Physics, 1999, 37 (11): 1165- 1182.
TOSCANO A , PITARRESI G , SCAFIDI M , et al. Water diffusion and swelling stresses in highly crosslinked epoxy matrices[J]. Polymer Degradation and Stability, 2016, 133, 255- 263.
ZAFAR A , BERTOCCO F , SCHJØDT-THOMSEN J , et al. Investigation of the long term effects of moisture on carbon fibre and epoxy matrix composites[J]. Composites Science and Tech-nology, 2012, 72 (6): 656- 666.
WANG Z , HUANG X , XIAN G , et al. Effects of surface trea-tment of carbon fiber:tensile property, surface characteristics, and bonding to epoxy[J]. Polymer Composites, 2016, 37 (10): 2921- 2932.
FENG Q , LI M , GU Y Z , et al. Experimental research on hygrothermal properties of carbon fiber/epoxy resin composite under different hygrothermal conditions[J]. Acta Materiae Compositae Sinica, 2010, 27 (6): 16- 20.
BULMANIS V N , GUNYAEV G M , KRIVONS V V . Risas-pavlam[M]. Moscow: USSR, 1991.
ZHANG Y J , ZHU X , MEI Z Y , et al. Equivalent estimating methods of ageing on polymer matrix composites residual strength[J]. Materials Review, 2012, 26 (8): 150- 152.