Analysis of elastic systems with discontinuous parameters
Constructions in the form of rectangular planar plates and shallow shells reinforced by a cross system of ribs of great rigidity and loaded with an arbitrary lateral load are considered. The stress-strain state of such structures is described by technical theories of plates and shallow shells. The effect of the stiffeners is taken into account in the equations as additional terms containing factors with the Dirac δ-function and its derivatives. The plate and the shell may have a stepwise variable thickness. The ribs are arbitrary thin-walled beams of variable cross-section that play an essential role in providing the load-carrying capacity of the structure as a whole. The stress-strain state of not only the plate and the shell but also the stiffeners themselves is determined. The questions of the rate of convergence of solutions in the form of trigonometric series describing the stress-strain state in the stiffeners are discussed. The results of analyses of reinforced plates are presented.
Analyzing simply supported plates using maple system
An analytical solution of a boundary problem for system of differential equations in displacements, describing a strain of the rectangular plate supported by ribs of rigidity is received. The solution is presented in the form of series with combination of regular and special singular functions which converge fast, and lead to simple computing algorithm.
Stress distribution instability in the plane problem of the theory of elasticity of heterogeneous bodies
A possibility of degeneration of relationships between stresses and their derivatives with respect to the coordinates in the plane problem of the elasticity theory is considered. For particular dependences of the parameters of elasticity on coordinates, curves are given, for which degeneration conditions are satisfied. It is shown that even a small inhomogeneity of the medium causes stress instability.