Experimental Investigation and Modeling of the Thermal Cycling Effect on the Mechanical Properties of CFRP

The effect of thermocycling on the mechanical properties of the laminated carbon fiber-reinforced plastic composite is investigated. Experimental data obtained for laminated carbon fiber-reinforced plastic by thermocycling are presented. Theoretical prediction of damage accumulation and degradation of mechanical properties in the laminated composite material is given. It is found that after 120 heating and cooling cycles at +80 degrees C/-195 degrees C the longitudinal Young modulus of elasticity reduces by 12%. It is assumed that degradation of properties is determined by damage accumulation. The model of damage accumulation is based on the description of damage growth in the monolayer and is built using known relationships of the composite mechanics for effective properties of laminated fiber composite materials. The stress and strain state of the laminated composite material under force and heat loading is tentatively estimated; the stress in the structural elements of the laminated package is taken into account in the damage increase models. The experimental data are used to identify the parameters of the model of degradation of the composite modulus of elasticity.