Study on Optimization for Strength and Vibration Characteristics of Turbine Blade with Complex Damping

An optimization system for turbine blade structure was established by combining the threedimensional finite element analysis and the mathematical optimization algorithm.The structural optimization of the fir-tree root-rim of a turbine blade with integral shroud and tie wire was conducted.The maximum equivalent stresses of the root and rim were reduced by 13.45% and 12.26% respectively,and the strength performance of the blade was improved correspondingly.Besides,based on a full circle self-locked blade of last stage,the optimization of the blade's shroud was conducted.The optimal structure of shroud made the blade frequency of each order satisfy the requirements of vibration security and improve the vibration performance of the blade accordingly.The optimization method developed in this subject has significant value for engineering application and is expected to provide support for the design of blade to some extent.