Diagnostics of Turbine Blades, Based on Estimation of Frequency Response Function

The aim of the study is to propose a diagnostics method based on blade’s vibration model in frequency domain. Amplitude spectrum A(ω) and phase spectrum φ(ω) have been experimentally identified which define transfer function G(jω) = P(ω) + jQ(ω) and their real P(ω) and imaginary Q(ω) parts. Transfer function G(jω) and resulting frequency, amplitude, phase characteristics and real P(ω) and imaginary Q(ω) parts are parts of blade’s diagnostics model. Changes in those characteristics are directly related to changes in the technical condition of the blades. It has been noticed that small changes in the technical condition cause large changes in frequency characteristics, which proves their usefulness in the diagnosis process.

The Dynamic Behavior Research of Coupling Shafts in Tufted Carpet Looms

Firstly, based on the structure of tufted carpet looms (DHGN801D-400), the lumped parameter models were built, in which included the massless shafts, lumped masses, disk and elastic support. Secondly, according to various parts of the relationship between force and deformation, the transfer matrix of right and left ends were established, thus the universal transfer matrix of shaft units was determined by solving the various parts transfer matrix simultaneously. Thirdly, the dynamic behavior model of coupling shafts in tufted carpet looms was given, and different natural frequencies were acquired by simulating the model in Matlab. Lastly, the dynamic behavior model using transfer matrix was verified to be effective and feasible by experiment.