Nonsteady-state damage accumulation processes in composite flanges under cyclic loads

We consider two typical flanges: for a powerplant casing and for the casing of suspensions with a sound-absorbing duct. We model the behavior of flanges under the action of cyclic external loads based on solution of the nonlinear axisymmetric problem of elasticity theory. In order to take into account fatigue fracture of the layers of the structure, we use maximum stress criteria, a tensor damage function, the rule of linear summation of damage, and reduction schemes for the deformation characteristics of the layers, describing different fracture mechanisms. We indicate the possible nature of the development of fracture zones in composite flanges. We have established the spare load-bearing capacity of the flanges after fracture begins.Report presented at the Tenth International Conference on Mechanics of Composite Materials (Riga, April 20–23, 1998).Perm State Technical University, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 33, No. 5, pp. 636–643, September–October, 1997.     

Two-scale simulation of damage in unidirectionally fibre reinforced composite materials

The finite element analysis of engineering structures usually assumes a homogeneous as well as a continuous medium. The heterogeneity of matter, which is always found on a sufficiently small length scale is neglected by replacing the inhomogeneous medium through a model of a mathematically homogenized material. The macroscopic constitutive behaviour is derived from volume averaging procedures that smear the microscopic heterogeneities. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Transversality of stable and unstable manifolds for parabolic problems arising in composite materials

In this paper we study one dimensional parabolic problems that arise from composite materials. We show that the eigenvalues and eigenfunctions of the associated linear unbounded operator have the Sturm-Liouville property and the nonincrease of the lap number along the solutions. These results are used to show that the stable and unstable manifolds of equilibrium points are transversal.     

Three-dimensional model of the deformation of twisted multilayered rods of composite materials

Conclusion An analytical approach based on certain assumptions regarding the character of the kinematic relations and equilibrium conditions was developed to calculate the stress-strain state of naturally twisted rods of composite materials. A computer program for calculating the stress and strain parameters in each layer was also developed. The results of calculations performed in accordance with the linearized variant (Eq. (5)) of general relations (4) agree satisfactorily with experimental data within a broad range of acting longitudinal loads. The method that was developed has been widely used in the design and optimization of several types of structures.Translated from Mekhanika Kompozitnykh Materialov, No. 4, pp. 610–614, July–August, 1990.     

Thermoelasticity problems in the mechanics of composite materials with large-scale deformation of the filler

A problem is posed and a method of solution developed for a class of thermoelasticity problems in the mechanics of composite materials with large-scale structural deformations, in which in the continuum approximation the composite material is modelled by a homogeneous orthotropic body with curvilinear orthotropy. As an application the authors establish the foundations of a theory of buckling for planar structural elements subjected to constant thermal fields.Translated from Matematicheskie Metody i Fiziko-Mekhanicheskie Polya, No. 29, pp. 16–25, 1989.     

The concept of nonideal interphase contact in the theory of deformation and failure of composite materials

We give a critical survey of the studies of the construction of mathematical models of the state of composite materials in the presence of nonideal interphase contact on the interfaces between the phases created by technological and physicochemical processes. We exhibit the essential influence of the parameters of adhesion on the macroscopic characteristics and resistance to failure of composite materials. Translated fromMatematicheskie Melody i Fiziko-Mekhanicheskie Polya, Issue 35, 1992, pp. 75–82.