Abstract
In steam-turbine manufactures, there are two main design groups; rotor (shaft) dynamics and blade dynamics groups who work independently. The former mainly calculate critical speed design of the shaft-bearing system. The latter design the off-resonance of blade vibrations at higher modes. However, we must consider the interaction between shaft vibration and blade vibration concerning the blade modes designated by nodal diameter k=0 and 1. This paper presents a theoretical analyses of coupled vibration between blade in-plane (nodal diameter k=1) vibration and shaft parallel motion from the viewpoints of stability and resonance. It also presents an experimental analysis using coupled resonance vibration data.
