Effect of the two-way reinforcing system on the load-carrying capacity of glass-reinforced plastic shells

The load-carrying capacity of thin cylindrical glass-reinforced plastic shells loaded by axial compression and external pressure has been investigated in relation to the characteristics of the two-way reinforcing system. The critical loads are expressed in terms of the characteristics of a parallel-reinforced layer with a coefficient that takes into account the reinforcing system and the shape of the cross section. The relations among the reinforcing layers optimal for the load-carrying capacity are determined and it is shown that independent two-way reinforcing substantially improves the load-carrying capacity of solid shells and shells with a nonload-bearing core.Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Mekhanika Polimerov, No. 6, pp. 1052–1058, November–December, 1969.     

Deformability and load-carrying capacity of netted composite rod assemblies with metal fittings

A technology is proposed for making netted rod assemblies with metal joints 3–5 times lighter than existing comparable structures. A procedure was developed for winding assemblies out of carbon-fiber-reinforced plastic (UKN-5000 and binder EKhD-MK). Results are presented from a study of the strain characteristics and load-carrying capacity of assemblies with different reinforcement schemes for different conditions of static damage. It is shown that the design of netted rod assembly proposed here is significantly superior to all known analogs with respect to specific stiffness characteristics and provides great dimensional stability in the case of unilateral heating of the product. The method is most effective if used to develop framework-type structures for use in space — platforms, telescope and antenna supports, and masts.Paper to be presented at the Ninth International Conference on the Mechanics of Composite Materials (Riga, October 1995).Translated from Mekhanika Kompozitnykh Materialov, Vol. 31, No. 3, pp. 387–392, May–June, 1995.     

Estimates of the proximity of a distribution to the normal law

Institute of Mathematics and Cybernetics, Academy of Sciences of the Lithuanian SSR. Vilnius University, Vilnius Civil Engineering Institute. Translated from Litovskii Matematicheskii Sbornik (Lietuvos Matematikos Rinkinys), Vol. 29, No. 4, pp. 657–673, October–December, 1989.     

Carrying capacity of thick-walled glass-reinforced plastic rings operating under pressure

Experimental data are presented on the carrying capacity and deformability of thick-walled rings made of unidirectional and two-way glass-reinforced plastic subjected to external and internal pressure. A limitation on the carrying capacity of the rings with increase in relative thickness is noted; an explanation of this effect is offered.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 6, pp. 1130–1132, November–December, 1971.     

Load-bearing capacity of compressible plates of glass-fiber-reinforced plastic with different placement of the reinforcement

The effect of placement of reinforcement on the load-bearing capacity of circular and rectangular plates compressible in the reinforcement plane was evaluated experimentally. Four placement schemes for circular plates and nine for rectangular plates were investigated. Different schemes of supporting the edges were studied. Two mechanisms of exhaustion of the bearing capacity were revealed. A numerical evaluation and comparison of different placement schemes with respect to the value of the critical and breaking load are given. The role of the actual realization of clamping and nonlinearity of the material is shown. A comparison with analytic relations taking into account the characteristics of the material is given.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, No. 4, pp. 646–653, July–August, 1972.     

The law of the iterated logarithm for normalized empirical distribution function

This paper deals with the law of the iterated logarithm and its analogues for sup , where the sup is taken on an interval of the form (a _n ,b _n ),(0a _n <b _n 1). Under certain conditions on a _n and b _n the corresponding lim sup results will be proved.     

Asymptotic law of distribution of primes of special form

Let N₀ be the set of natural numbers whose binary expansions have an even number of 1’s, and let N₁ = N\N₀. In this paper, we obtain asymptotic formulas for the number of primes p not exceeding X and such that p ∈ N_i, p + 1 ∈ N_j, where i and j take values 0 and 1 independently of each other.     

Carrying capacity and deformation properties of glass-reinforced plastic pipes of various construction

Glass-reinforced plastic pipe under internal hydrostatic pressure starts to sweat at loads lower than the mechanical strength of the material. It is established that the life of such pipes is well described by an exponential law. The leakage mechanism is mainly controlled by the deformation properties of the reinforcement and resin. The period of reliable service can be estimated from the time of development of the strain corresponding to the end of the phase of steady-state creep. It is shown that for pipe made with cross-wound glass rovings, the winding angle and the number of roving ends have a considerable influence on the creep and life.Mekhanika Polimerov, Vol. 3, No. 6, pp. 1082–1088, 1967     

A simulation study for the distribution law of relative moments of evolution

Nine selection‐survival strategies were implemented in a genetic algorithm experiment, and differences in terms of evolution were assessed. The moments of evolution (expressed as generation numbers) were recorded in a contingency of three strategies (i.e., proportional, tournament, and deterministic) for two moments (i.e., selection for crossover and mutation and survival for replacement). The experiment was conducted for the first 20,000 generations in 46 independent runs. The relative moments of evolution (where evolution was defined as a significant increase in the determination coefficient relative to the previous generation) when any selection‐survival strategy was used fit a Log‐Pearson type III distribution. Moreover, when distributions were compared to one another, functional relationships were identified between the population parameters, revealing a degeneration of the Log‐Pearson type III distribution in a one‐parametrical distribution that can be assigned to the chosen variable—evolution strategy. The obtained theoretical population distribution allowed comparison of the selection‐survival strategies that were used. © 2012 Wiley Periodicals, Inc. Complexity, 2012.