The selective method of calculation because of the profitability is successfully applied several centuries. However when calculating non-failure operation in case of fatigue failures (often sudden) when there is a considerable sedate communication of m=10-15 for the supermulti-cycle field of loading between durability (hardness, an endurance limit) and the operating tension, decrease in the minimum resource of details will make 10-100 and more times. It turns out because of an unaccounted main part of population. In our example of 104-50=9950 pieces of such details, i.e. their potential refusals. Therefore for this case a selective method – the intermediate stage of calculations.

Keywords: selection, fatigue resource, population of final volume, sedate communication

dependences of value distribution of hardness of an armature of the class A500C of different diameters are constructed. For determination of the minimum values the method of graphic transition from selective data to set is used. Calculation of the smallest values of hardness using the shift received in the analysis of set is carried out.

Keywords: selection, armature, population of final volume

The article deals with the analysis of the application of the method of NS. Strelets for the static calculation of construction structures. It is proposed on the basis of the probabilistic-statistical method NS. Streletsky instead of the normal laws for operating voltages and strength apply laws with a shift, in particular, the law of the Weibull with three parameters and the Fisher-Тippet. It is proposed to make the transition to the parameters of the totality of the finite volume that will allow to increase the accuracy of calculation of probability of failure-free operation and the proposed probabilistic safety, and also to optimize the probability of trouble-free operation of construction structures

Keywords: optimization, design, construction, steel, sample, weibull, fisher-tippet