The multilevel approach to studying the influence of the volumetric ratio in components of unidirectional carbon fiber composite on its mechanical properties

The problem of predicting effective mechanical properties of composite materials is considered. This problem is solved on the basis of the multilevel approach to the description of the material structure. For every level of the composite structure, the influence of damage accumulation on the formation of mechanical properties of the material is considered. The possibility of a detailed investigation of the influence of micro- and mesoscopic level effects on the formation of effective mechanical properties of the composites is shown. The proposed numerical procedure is used for the estimation of effective properties of model composites with volume ratios of carbon fiber ranging from 7 % to 50 %. The task of estimating local properties of materials is solved by the finite elements method. The ultimate values of strength and strain of the composite are determined as a result of studying the evolution of clusters of damages in representative volumes of the material. It is shown that these values grow nonmonotonically with an increase in the volume ratio of reinforcements. The results obtained have a good compliance with known experimental data.