Larin O. Vibrations of the steam turbines driving wheels blading with deterministic and random mistuning of the shrouding parameters

The subject of investigation lays on oscillations of working wheel bladings with the determined and random mistuning of the parameters of the bandage joint. Aim of the work consists in the methods of the analysis and determination of regularity of influences on the determined and casual mistuning of the parameters of bandage link on shaping of turbomachines working wheels bladings oscillations. Research methods: fundamental rules of theory of elasticity, the theory of oscillations and probability theory. For the analysis of the SST and natural oscillations the finite element method, for AFC of systems researching with casual parameters was executed on the basis of methods of reducing the stochastic basis, the parametric probability analysis and Monte-Carlo. Theoretical worth of dissertational thesis consists in the offered method of calculation of probability rates of the steady forced harmonic motions of cyclically symmetric constructive elements of machines with taking into account a casual mistuning of their parameters. Practical value: developed parametric models of steam turbines blades; created software for calculations of probability rates of characteristics of the steady forced harmonic motions of systems with the casual and determined mistuning which allows to use existing program systems of the engineering analysis; numerical researches of the mistuned blading of 3 steps CLP of the steam turbine and mates recommendations about lowering the possible vibrations. Novelty: for the first time it is developed the method of solution of a problem of steady forced harmonic motions of cyclic mechanical systems with a casual mistuning which gives the chance to carry out researching on the basis of three-dimensional FE sector models; for the first time it is offered the methodology of construction parametric FE models of blades; new regularity of agency of small casual technological aberrations in parameters of the bandage joint on vibration performances of blade disk assemblies is determined. Heading extent: results and recommendations are involved to the process if designing a new and modernization an existing constructions of steam turbines blades in special design bureau OS "Turboatom" (Kharkiv). Use orb: the method and the software can be used in scientific and applied researches, at the designing the cyclical engineering constructions, which widespread in power, aviation, and transport techniques.