Research On Damping Properties Of Glass/Carbon Fiber Hybrid Composites In Hydrothermal Environment

Glass/carbon fiber hybrid composites combine the high strength of carbon fiber and the high strain failure of glass fiber and are widely used in aerospace,automotive,marine,and military fields.The development and progress of science and technology have put forward higher requirements for the design,application and vibration control of glass/carbon fiber hybrid composites,especially the hydrothermal environment has an important influence on the mechanical properties of glass/carbon fiber hybrid composites.Therefore,it is of great significance to research the damping properties of glass/carbon fiber hybrid composites in hydrothermal environment.Based on considering the influence of hydrothermal stress and hydrothermal environment on the mechanical properties of the lamina,according to the principle of energy dissipation,combined with the classical laminated plate theory and macro strain energy method under hydrothermal environment.The macroscopic theoretical model and mesoscopic theoretical model of damping prediction of laminated beams of glass/carbon fiber hybrid composites in hydrothermal environment are established,and the solution program of loss factor of glass/carbon fiber hybrid composites is compiled by using Matlab software.The effects of different structural parameters of laminated beams on the loss factor of glass/carbon fiber hybrid composites in hydrothermal environment were studied.The specific research contents and conclusions are as follows:(1)From the perspective of composite macroscopic mechanics,based on the macroscopic strain energy method and combined with the mechanical property attenuation model of the composite lamina in hydrothermal environment,the macroscopic theoretical model of damping prediction of fiber hybrid composites in hydrothermal environment is established.According to the established damping prediction theoretical model,taking the symmetrical laminated beam of glass/carbon fiber hybrid composites as the research object,a program for solving the loss factor of glass/carbon fiber hybrid composites in hydrothermal environment is compiled based on MATLAB software.(2)According to the Matlab program for calculating the loss factor of glass/carbon fiber hybrid composites in hydrothermal environment,the engineering elastic constants of glass fiber/epoxy lamina and carbon fiber/epoxy lamina under different temperatures,moisture absorption concentration,and hydrothermal environment are calculated.The results show that the moisture absorption concentration has little effect on the engineering elastic constants of the lamina.Compared with temperature and moisture absorption concentration,the hydrothermal environment significantly reduces the elastic modulus of glass fiber and carbon fiber/epoxy laminas.(3)Based on the micromechanics of composites,the effects of different glass fiber volume fraction,carbon fiber volume fraction,stacking sequence,and hybrid ratio on the damping characteristics of glass/carbon fiber hybrid composites were studied.The results show that when the glass/carbon fiber hybrid composite adopts 0° unidirectional fiber ply angle,the damping properties of laminated beams can be improved by using lower carbon fiber volume fraction and appropriately increasing glass fiber fraction.For the sandwich hybrid mode of glass fiber reinforced composite lamina in the outer layer,the carbon fiber composite lamina with fiber volume fraction of 0.45 should be placed in the core layer,and appropriately increasing the volume fraction of glass fiber can improve the damping properties of glass/carbon fiber hybrid composites.Increasing the number of glass fiber/epoxy laminas can improve the damping properties of glass/carbon fiber hybrid composites with different stacking sequence.