Effect Of Temperature And Humidity On Mechanical Properties Of T700S/#2510and G30-500/TC275Composites

As a kind of advanced composite material, Carbon fiber reinforced polymermatrix composites was widely applied in aerospace field, as a result of its lightweight, high strength, corrosion resistance and so on a series of advantages.However, the mechanical properties of polymer matrix composites will decrease inhot and humid environment, what’s more, the stress condition of polymer matrixcomposites is very complicated under different environmental impact and differentloading ways due to its heterogeneity. the reliability in environment was lack ofsystem research and evaluation so far. Currently, there is no a complete systemwhich can be used in the reliability assessment of the influence of environment onthe composite materials. In this paper, To study the mechanical properties of twokinds of composites(T700S/#2510and G30-500/TC275) experiments(tensile test,compression test and shear test) were carried out in different environments such ashigh temperature(82℃), room temperature, low temperature(-55℃) and humidity.We have analyzed their characteristic of water absorptivity and test theglass-transition temperature of them between driest and wettest; compared theirmechanical properties; study the mechanics performance of carbon fiber compositesin the hot and humid environment.The experimental study indicates that Carbon fiber composite laminated havetwo stages of moisture absorption; it is a linear process during the first stage, butshowed nonlinear in the second stage and it obeyed to the Fick’s second law; underthe same layer ratio, it has a faster absorption rate when it become thinner; within acertain range size and with the same thickness, the higher proportion of layer of45°direction, the faster the water absorption by composite; the glass-transitiontemperature of carbon fiber composite in wettest is30℃lower than that in driest;the tensile and compressive performance of T700S/#2510were higher than these ofG30-500/TC275; the two composites have the same shear performance; temperatureand hygrothermal environment has little effect on tensile strength and modulus ofcarbon fiber composite; under the environment of high temperature the compressive strength of fabric has fallen by9.1%~15.9%and the compressive of unidirectionaltapes(90°) has fallen by19.1%; in low temperature environment the compressive offabric has little change while that of unidirectional tapes(90°) increased by10.3%;compressive strength residual and shear strength residual of fabric are about75%and67%respectively under the environment of ygrothermal environment carbonfiber composite material damage to brittle failure, but it turn into plasticity in theygrothermal environment.