Numerical Simulation of the Vibration Characteristics for the Blade with Zigzag Shroud

Based on the hysteretic spring friction model,the natural frequencies and modal characteristics of the single blade and a circle of blades were calculated under different rotating speeds,and the characteristics of the dry friction damping of the blade with zigzag shroud were analyzed.The influence of rotating speed on the blade with zigzag shroud was analyzed.Through analyzing the internal contacting status of the blade shrouds,the friction force and the relative sliding distance between the blade shrouds were obtained,thus the equivalent damping and the equivalent stiffness between the blade shrouds were calculated. The element of MATRIX 27 in finite element analysis software was introduced as a spring damping element to simulate the internal damping and stiffness in the contacting area between the blade shrouds,and to analyze the dynamic stress for the blade with the zigzag shroud.Results show that the damping effect is obviously for the dry friction between the blade's zigzag shrouds,and can efficiently control the system vibration.