There submitted the specification of deformed solid body boundary value problem in polar coordinate system. The problem is transformed to the special integral equation while the solution of this problem permits to define local stresses on the conjugation line nearby its concentration.

Keywords: stress concentrator, elastic body, local stress, boundary value problem, integral equation

The problem of stress concentration near step junction of sections in constructional elements and machine elements has been solved in this article by means of one singular integral equation. The formula for determination of stress concentration factor depending on fillet radius has been submitted.

Keywords: Step plate, singular integral equation, conjugation line, stress concentration factor

There submitted a HF and SHF field energy density measuring technique developed by authors in this work with application of semiconducting laser interferometer measuring an alteration of a glass plate optical thickness while the plate is placed in the sphere of HF or SHF heating. Operability of the technique is demonstrated by measurement of a microwave oven electromagnetic field energy density distribution

Keywords: laser interferometer, temperature measurement, HF and SHF field sensor

The stochastic model of an assessment of mechanical characteristics of strength on the basis of the analysis of function of reliability is offered. Communication of function of reliability with normative factor of safety factor is correlated. Recommendations to destination mechanical characteristics of strength on Gauss to a level and factors of a variation are given. Analytical and graphic dependence for optimum purpose of parameters of reliability of units of hardware on the lead strength researches is offered.

Keywords: Strength, reliability, factor of a stock, mechanical characteristics, the likelihood analysis

An accurate solution of problem for a plane horizontal cutout is proposed where stress concentration subject to geometrics of the cutout is considered. This solution makes possible to solve problems relating to optimum designing of structures and machinery with similar technological elements.

Keywords: cutout, conjugation, problem, equation, solution, stress.