Entity

Time filter

Source Type


Boiko D.V.,Chaplygin Siberian Research Aviation Institute | Zheleznov L.P.,Chaplygin Siberian Research Aviation Institute | Kabanov V.V.,Chaplygin Siberian Research Aviation Institute
Mechanics of Solids | Year: 2012

The finite-element statement of stability problems for stiffened oval cylindrical shells is presented with the moments and the nonlinearity of their subcritical stress-strain state taken into account. Explicit expressions for the displacements of elements of noncircular cylindrical shells as solids are obtained by integration of the equations derived by equating the linear deformation components with zero. These expressions are used to construct the shape functions of the effective quadrangular finite element of natural curvature, and an efficient algorithm for studying the shell nonlinear deformation and stability is developed. The stability of stiffened oval cylindrical shells is studied in the case of combined loading by a boundary transverse force and a bending moment. The influence of the shell ovality and the deformation nonlinearity on the shell stability is investigated. © 2012 Allerton Press, Inc. Source


Boiko D.V.,Chaplygin Siberian Research Aviation Institute | Zheleznov L.P.,Chaplygin Siberian Research Aviation Institute | Kabanov V.V.,Chaplygin Siberian Research Aviation Institute
Mechanics of Solids | Year: 2012

The variational finite element method in displacements is used to solve the problem of geometrically nonlinear deformation and stability of cylindrical shells with a noncircular contour of the cross-section. Quadrangle finite elements of shells of natural curvature are used. In the approximations of element displacements, the displacements of elements as solids are explicitly separated. The variational Lagrange principle is used to obtain a nonlinear system of algebraic equations for the unknown nodal finite elements. The system is solved by the method of successive loadings and by the Newton-Kantorovich linearization method. The linear system is solved by the Crout method. The critical loads are determined in the process of solving the nonlinear problem by using the Sylvester stability criterion. An algorithm and a computer program are developed to study the problem numerically. The nonlinear deformation and stability of shells with oval and elliptic cross-sections are investigated in a broad range of variation of the elongation and ellipticity parameters. The shell critical loads and buckling modes are determined. The influence of the deformation nonlinearity, elongation, and ellipticity of the shell on the critical loads is examined. © 2012 Allerton Press, Inc. Source


Boiko D.V.,Chaplygin Siberian Research Aviation Institute | Zheleznov L.P.,Chaplygin Siberian Research Aviation Institute | Kabanov V.V.,Chaplygin Siberian Research Aviation Institute
Mechanics of Solids | Year: 2011

We present a finite-element statement for the solution of stability problems for reinforced elliptic cylindrical shells with moment properties and nonlinearity in their precritical stressstrain state taken into account. Integrating the equations obtained by equating the linear strain components with zero, we find explicit expressions for the displacements of elements of noncircular cylindrical shells as rigid bodies. Using these expressions, we construct the shape functions of a fourangle finite element of natural curvature and develop an effective algorithm for studying nonlinear deformation and stability of shells. We study the stability of reinforced elliptic cylindrical shells under combined loading by a transverse boundary force and a bending moment and investigate how the ellipticity of the shells and the nonlinearity of deformation at the precritical stage affect the shell stability. © 2011 Allerton Press, Inc. Source

Discover hidden collaborations