No 4 (2014)

This paper investigates the invariant algorithms for the forming of normal surfaces and examples in their usage in graphic design and in modeling of summer, winter, water slide and sledge track gutters are given. It is shown on the Guido Grandi spatial roses example, how the usage of analytical smooth rails of normal surfaces allows us to obtain the variety of decora- tive forms. A method for the modeling of safe slides is given by joint integration of Frenet equations, the equations for the dynamics of the unfree material point and the dynamical shap- ing of normal surfaces is presented.

The article discusses the results of calculation of the critical load for high-rise buildings with a hinged frame design scheme (total resistance as the perception of horizontal (wind) loads, provided the kernel hardness (trunk bearing skeleton.) And hard (total resistance pro- vided by the carrier core columns, diaphragm stiffness a horizontal trunk and hard drives over- lap and cover)

Some problems of temperature field influence on the growth inhibition of curved crack in the strip (beam) when the strip is bent in the plane by given load system (constant bending moments, uniformly distributed pressure and other) is consider. The equilibrium problem of curved crack with partially contacting faces under action of external loads, induced tempera- ture field and forces on the contacting crack surfaces is reduced to the problem of linear con- jugation of analytic functions. It is assumed that on some part of the contact faces engagement occurs and on other part the slip is possible.

The super-element of column with rectangular cross section, suggested by authors earlier for linear analysis of columns of homogeneous materials, was developed with the purpose of reinforced concrete columns analysis. The element was implemented into a finite element pro- gram PRINS, and consisting of this program can be used for linear analysis of building struc- tures containing the reinforced concrete columns

The design of bars, lying on an elastic base is fulfilled usually with help of a simple model of the base proposed by Winkler-Zimmerman. This hypothesis was subjected to the repeated critics, because it doesn't take into account the influence of base fields, which are near to the point of the application of the concentrated force. Many models of the elastic base were proposed later by other authors, which allow to smooth away the indicated shortage of the Winkler-Zimmerman model. One more attempt of an improvement of this model is made in the present work

The work is devoted to experimental study of polyester-wood composite under dynamic loading. Based on a thermodynamic approach, the objective is the evaluation of the specific energy of interfacial delamination in a multi-layer composite material under dynamic loading causing damage to it by cracking. For modeling of dynamic loading, it was used an experi- mental device based on the principle of the Charpy test which is to measure the residual en- ergy of a mass movement following a shock at speeds generally between 1 and 4 m/s, on a test piece cut of standardized dimensions requested in bending. Some of the available energy is consumed by rupture of the test piece. The results of this work showed that for a dynamic test, the fracture energy is function of the speed and impact energy of fall of the load. These results may be useful in the design of multilayer composite structures subjected to dynamic loads