Finite element modeling of integral viscoelastic properties of textile composites

Abstract

The problem of modeling the effective integral viscoelastic properties of unidirectional composite materials is considered. To calculate the integral properties of viscoelasticity, the Fourier transform and the inverse Fourier transform are used, as well as the method of asymptotic averaging for composites with steady polyharmonic vibrations, and a finite element algorithm for solving local problems of the viscoelasticity theory on the periodicity cell of the composite. To obtain the material constants, a method of approximation of the Fourier images of the relaxation and creep kernels is proposed, which makes it possible to avoid the numerical error of the inverse Fourier transform.

Finite element modeling of thin-walled shell composite structures

“…We will assume that the following assumptions are satisfied, which are usually accepted in shell theories of the Timoshenko type [1,10]:…”

“…Methods of two-dimensional theories of plates and shells are often used to calculate engineering thin-walled structures [1][2][3][4][5][6][7][8][9][10][11][12][13][14], which allow to reduce the dimension of the problems from 3D to 2D problems, which, require significantly lower characteristics for the computer technology used. However, when solving problems in the theory of thin-walled plates and shells, additional difficulties arise, in particular, the problem of the accuracy of approximating the solution of the problem in terms of the thickness of the shell [5], the influence of the finite element type on the solution, as well as the problem of correct conjugation of the solution in the junction zone of various shell structural elements In this paper, a numerical algorithm for solving the problem of elasticity theory for shell composite structures, including complex structures, is proposed.…”