Theoretical And Experimental Research On Vibration-impact Characteristics Of Turbine Shrouded Blades

By using theoretical and experimental methods, the mechanism of vibro-impact and the effective factors of Steam Turbine Blades with Integral Shroud are studied.On the theoretical study, a nonlinear damping model has been used to establish integral dynamics equation for three-dimensional entity unit of the collision damping blade. With the help of 3D software Solidworks, the solid models of blade is built. With the aid of FEA software ALGOR, the dynamics and static characteristic of single blade are obtained, and also the Campbell map is drew. Influence of such dimensions as blade shroud clearance, exciting force amplitude and symmetry of shroud clearance structural, etc. The results of the analysis indicate that the collision structural is a good vibration reducing structural, the blade with collision conditions can suppress external force by doing-work. Smaller the gap, better the damping effects. The dynamic stress is not sensitive to the exciting force, which means that the peak stress changes little at a certain gap. Asymmetry gap has better damping effect than symmetry one.On the experimental study, the experiments on dynamics characteristics and blade vibration abatement mechanism of constant section ISB are researched by utilizing the rotor experiment table and a test system. The results of the experiments indicate that smaller the gap, better the damping effects. The dynamic stress is not sensitive to the exciting force; Asymmetry gap has better damping effect than symmetry one; All those results conform to the theoretical analysis results.Basing on the study results above mentioned and research results of other investigators, a preliminary quest of reliability design criteria of ISB is made.The research results provides a effective method to the design and reliability analysis of ISB. And has a important engineering application value to manufacture and model change of ISB.