The term "sustainable development" appeared not so long ago. The growing concentration of industrial enterprises situated on urban areas, the uncontrolled increase in the scale of development, reduction the share of the recreational areas, replacing the areas of industrial purpose and new lines of transport and engineering service lines, has led to imbalance of technogenic and natural environment. The larger and more comfortable become the city, the more resources they need and the higher risk the natural of irreparable harm for the environment. This problem is connected, firstly, with the concentration of large numbers of people in one place, secondly, to human psychology, and ethics. It is hard to realize that the consumption of resources may be limited and you should think about the needs of future generations. In contrast to this tendency the idea about the need to rethink the traditional principles of urban development and forming the new basic principles of urban development, was put forward. It called the concept of sustainable development. This concept is based on a combination of economic, social and environmental criteria, which take into account the interests of future generations.
An important aspect of the theory of optimal design of shells is a question technology of determination of optimal forms of shells with numerical methods, based on the variation definitions. The distribution of effort in sloping shell of revolution optimal form, uniformly loaded with despens intensity is analyzed. The mathematical model of shell optimal form is based on the maximum principle of L.S. Pontryagin. The solution of the objective is numerically made in MathCad. The relations of the distribution of the longitudinal forces and moments along the radius of the shell is shown.
The criteria of the buckling of engineering structures in terms of the systems with lumped parameters are discussed in the article. The examples of setting buckling problems and their solutions using Timoshenko and Bryan criteria's, and the criterion of the critical levels of energy are given. The analysis of the compared approaches, their strengths and shortcomings in terms of the multi-degree systems are presented.
Composite structures require the use of modern reinforcing materials combining high strength characteristics and resistance to aggressive influences with low weight. One of the promising materials for the production of reinforcing products is basalt roving. The high strength of the thread in combination with fragility imposes certain limitations on its placement in the material, and requires new approaches to the design of the reinforcing bar itself. The article investigates the strength characteristics of a composite reinforcing bar made of a basalt complex thread proposed by the authors. The features of the test procedure and the mechanical characteristics of the reinforcing material are described. The effectiveness of the applied test method developed in the process of testing reinforcing rods is shown. An increase in the tensile strength of a composite reinforcing bar based on basalt fiber is established in comparison with products from fiber and roving.
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