Three-dimensional representative volumetric elements for the construction of composite materials with improved mechanical properties

Abstract

A methodological and software tool was developed for the effective assessment of the properties of three-dimensional composites of the matrix type and periodically structured composite materials using modern methods of boundary and finite elements. Continuum mechanics models have been modified to adequately describe the behavior of composites, numerical simulation models and software have been adapted to these models for solving static problems and problems in the frequency domain. The novelty, advantages and efficiency of the developed computer technology are provided by theoretically grounded models for the analysis of composites of three-dimensional configuration with non-canonical particle shapes, improvement of modern boundary and finite element methods and coupled algorithmic schemes to achieve high accuracy of calculation analysis; suitability for the analysis of both static and dynamic elastic fields in the considered structures. Calculation models and software tools have been developed that allow to take into account special forms of individual and interacting inhomogeneities in a three-dimensional matrix, in particular, with an emphasis on short fibers and tubes. These models and methods are applied to the study of static and dynamic characteristics of launch vehicle tanks made of various composite materials. For the studying free and forced oscillations of shell structures with compartments containing liquid, the method of natural modes  has been developed. Composites with an aluminum matrix with steel spherical inclusions and with steel and carbon fiber inclusions were considered as tank materials. The proposed models and computer simulation algorithms allow to carry out the numerical analysis of three-dimensional static problems under classical conditions of contact with the matrix; three-dimensional problems regarding the static interaction of a finite number of inclusions in the matrix; research of ordered and stochastically distributed inclusions; study of inclusions in the form of spheres, cylinders, carbon tubes and inclusions in the form of hollow spheres and to determine the effective elastic parameters of three-dimensional matrix composites with spherical inclusions, fibers and tubes. The results of the calculations showed strengthening of the obtained composite materials with a simultaneous decrease in density