Наукові горизонти (May 2019)
EXPRESS EVALUATION OF THE RELATIVE COST OF METAL STRUCTURAL MATERIALS FOR THE SPECIFIED OPERATING CONDITIONS AND THE SPECIFIED RESOURCE
Abstract
The process of designing a new machine or design is a constant need to make decisions in the face of uncertainty: from the design idea, layout, and to the choice of materials and equipment. At the same time, the indicators of reliability and cost, which are refined for a long time at the stage of testing a prototype and under controlled operation, remain virtually unrecorded. It is too expensive and requires considerable time. How can these indicators be taken into account at the design stage, reducing time and costs? In addition, the service and operational characteristics of a metal structural material: chemical composition, short-term, cyclic and long-term strength, ductility, crack resistance - form a multidimensional vector, each of which components separately weakly correlates with the market price of the alloy, which does not directly allow us to estimate the cost of the structure and not allows a priori ranking of alloys according to a comprehensive assessment of value under specific conditions with given parameters of temperature-force load on a given resu a. For the first time such a statement of the problem was formed in our publications cited in the list of references. This research is their further development. The methodology for estimating the relative cost of modern metallic structural materials for given operating conditions (load, temperature, resource) and alloy properties (reduced coefficient of quotation, melting point, specific gravity) is given. On the basis of these estimates and the previously proposed universal generalized diagram of a prof. Grabara, for the first time, they managed to obtain comparative estimates of the cost of metal structures for a wide range of their operating conditions (stresses, temperatures and resource), referred to the unit of operation time. This methodology allows a significant reduction in the level of uncertainty, and can be applied already at the stage of preliminary design of the machine. The approach outlined in the paper opens up good prospects for a deeper feasibility study of engineering solutions at the stage of preliminary machine design. Examples of calculation.
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