Stress Concentration in Microstructural Elements of Viscoelastic Composite Materials

Abstract

539.4We present solution of the problem of estimating the stress concentration in the constituents (matrix and inclusions) of a multiconstituent viscoelastic composite material, depending on the shape of inclusions, properties of the matrix and the whole composite. The matrix material is isotropic and viscoelastic. A wide range of properties of inclusions (e.g., pores, solid and viscous particles) is considered. To solve this problem, we use the method of integral transformations.Progress in technology requires developing novel engineering structures, mechanisms and multi-purpose machines, which, in its turn, requires the use of materials with the properties that are absent for conventional materials and alloys. It is necessary to develop the composite materials in which the required properties are synthesized by selecting the appropriate constituents and controlling their mutual arrangement. The rheonomic properties are typical of many of those materials to one extent or the other. A negligible number of publications are devoted to the problem of stress concentration in viscoelastic bodies [1,2]. The behavior of the composite material with an elastic matrix was studied thoroughly [3][4][5][6]. Numerous works investigated the concentration of mean stresses in viscoelastic composites composed of two constituents [7]. The solution of the problem of determining the concentration of mean stresses in the constituents (matrix and inclusions) of the multiconstituent viscoelastic composite material is given below.The service conditions of the composite materials are characterized by high levels of external loads, temperatures, electric and magnetic fields. The linearity of relationships between the dynamic and kinetic parameters that describe the material behavior under such conditions can be violated and the use of the linear deformation theory results in considerable errors. These features are peculiar to the composites with both viscoelastic metallic and polymeric matrices which are increasingly used in elements of state-of-the-art structures.