Criteria of Minimum Materials Consumption for Bars with Rectangular Cross-section and Restrictions on Stability Or Limitations on the Value of the First Natural Frequency

Apparatus of mathematical programming is normally used in the most part of research works, dealing with structural optimization. However, the special properties of optimal systems have been identified in several studies. Besides, corresponding criteria, which have been formulated as well, can be used for assessments of proximity of optimal solutions to minimal material consumption. Particularly relevant criteria for bars with rectangular cross-section and restrictions on the stability or limitations on the value of the first natural frequency have been formulated. However, not all the features of some of the criteria have been observed. In addition it seems appropriate to identify relevant criteria for special cases set variable parameters. The distinctive paper contains additional property proximity criterion of optimal solutions to minimal consumption of materials for the bars with a rectangular cross-section and limitations on the value of the first natural frequency, modification of one of the previously proposed criteria and formulation of appropriate criterion for the case where one of the parameters of variable rectangular cross-section is constant along the length of the bar.