FIELD: measurement technology, testing of building structures of beam type. SUBSTANCE: method establishing value of prestressing of fittings in loaded structure of beam type with transfer of prestressed effort on its butts consists in excitation of free vibrations in structure before and after stress, in measurement of corresponding fundamental frequencies of vibrations and in analytical determination of integral value of prestressing of fittings with due account of these frequencies of vibrations, summary area of reinforcement bars, their length, weight of structure and eccentricity of application of effort relative to neutral axis of section. Tested structure is loaded uniformly with distributed load, fundamental frequency of vibrations is measured under loaded state and value of prestressing of fittings is established. EFFECT: increased precision of establishment of value of prestressing of fittings with allowance for their compliance and with due account of first losses of prestressing related to compression and deformation of structure as whole.
