Influence of crack on vibration and acoustic radiation characteristics of three-dimensional elastic body of gear structure

The influence of crack on the radiation characteristics of the sound field of gear structure was discussed by analyzing the reference circle crack and root crack in gears. The models of three-dimensional elastic body corresponding to root crack and reference circle crack were established respectively, the dynamic analysis and modal analysis of the two kinds of models were achieved by use of ANSYS, and various parameters useful for analysis were acquired. Based on these with the help of MATLAB and the theory of thick circular plate, the acoustic characters of reference circle crack and root crack in gears were obtained and the distributions of sound pressure on the r=0.5 m sphere surface and axial sound pressure of cracked gear structure were achieved. Based on the analysis and comparison of the results, the influences of the location and depth of cracks on acoustic characteristics of gear structure were presented. These provide a theoretic foundation for gear fault diagnosis using the acoustic method in engineering.