No 1 (2011)

The geometrical research of translational surface formed by the circle of constant radius supported by two meridians of the sphere or the torus is presented. The vector equations are derived in lines of translation and in lines two of which coincide with the given meridians. The opportunity of design of umbrella shells is illustrated by the example of the real building. The umbrella surfaces of positive and negative Gauss curvatures are presented.

In work advise to construction of criterion of durability loaded corrosion damaged concrete are given at plane stress, necessary for the decision of problems of survivability of ferro-concrete constructive systems in the conditions of simultaneous display power and excited environment extremal influences.

The model "design-foundation-basis" in the form of the two-layer beam which bottom layer corresponds to the foundation, and top - designs with the corresponding resulted characteristics are developed. The model considers the joint work of construction and the foundation on elastic foundation. From the general equations of elasticity theory, taking into account the mass forces obtained resolving equations and formulas for the three components of stress. The dependencies of internal forces in a beam of high design, as well as diagrams of the stresses for the model and the traditional formulation of the problem. It is shown that the stress diagrams for the two considered design schemes differ considerably.

Viscoelastical deformation model based on fractional derivatives submitted. Model parameter determination is described. It allows to predict system behavior under different loading.

Now for the analysis mode of deformation of the majority shell of constructions of a building and machine-building structure use modern computer complexes such, as ANSYS, NASTRAN, ABACUS and others. All these complexes have the convenient multipurpose interface, powerful library of finites elements, and in most cases effectively allow to investigate processes of deformation of constructions in linear and nonlinear statements. At the same time it is not necessary to forget that adequacy of the received parameters is mode of deformation of constructions in the certain degree depends on those hypotheses, preconditions, models of elements of discretization, ways of approximation and other factors which are realized in this or that computer complex. So, for example, all modern finites elements settlement complexes are based on the elements constructed on independent interpolation to procedure which essence consists that everyone of a component of a vector of displacement of an interior point of an element of discretization is interpolated through pivotal values of this components and other two component does not depend on modes values, that not always reduce to reception of acceptable results. In present article view variants of reception interpolation expressions on an example of a finite element axially symmetric the loaded shell of rotation with six degrees of freedom in node and are considered, and high efficiency of algorithm with vector interpolation of displacement fields.

The numerical approach to the decision of dynamic problems with unilateral constraints and Culon's friction is offered. The decision is formulated on the basis of step-by-step analysis (in time) method with use of frame contact finite elements. The reduced algorithm is illustrated by numerical example.