In the work, within the framework of the linear spatial theory of elasticity, using the modified variational principle of Hu – Washizu, a system of homogeneous differential equations of stability in partial derivatives is obtained. On this basis, a study of the stability of a cylindrical shell structure of a tunnel structure is carried out.Reduction of the dimension of a three-dimensional system of differential equations became possible using the procedure of theanalytical method of Bubnov – Galerkin. In this case, an expansion of the unknowns of the system of stability equations in double trigonometric series along the generatrix and in the circular direction of the shell was used. On this basis, a one-dimensional infinite resolving system of differential equations of stability of anisotropic cylindrical shells in the normal Cauchy form is obtained. Using the numerical method of discrete orthogonalization, an algorithm is developed and a computer software package for a PC is compiled, which in a single process combines the determination of the parameters of the subcritical stress-strain state and the solution of problems of stability of anisotropic cylindrical shell structures of tunnel structures in a spatial statement.The stability of a steel cylindrical shell under distributed lateral pressure has been studied. The obtained result has been compared with critical loads determined for a steel shell reinforced with a unidirectional fibrous composite boroplastic, which can be laid at arbitrary angles to the cylinder generatrix. The obtained calculation results have been analyzed and the importance of shell reinforcement with fibrous composite for reliable increase of critical load values has been noted.
Author Biographies
V. M. Trach, National University of Water and Environmental Engineering
Doctor of Engineering, Professor
A. V. Podvornyi, National University of Water and Environmental Engineering
