WEI J P, ZHANG J Z, WEN Z H,et al.Study on natural frequency characteristics of coal based on the influence of bedding and coal rank[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(1):1-8.

doi:10.16186/j.cnki.1673-9787.2021070109

Received:2021/07/29

Revised:2022/02/28

Published:2023/01/25

Study on natural frequency characteristics of coal based on the influence of bedding and coal rank

WEI Jianping1,2,3, ZHANG Junzhao1, WEN Zhihui1,2,3, REN Yongjie1, ZHANG Libo1

1.School of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China；2.State Key Laboratory Cultivation Base for Gas Geology and Gas Control，Henan Polytechnic University，Jiaozuo  454000，Henan，China；3.Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization，Henan Polytechnic University，Jiaozuo  454000，Henan，China

Abstract:In order to exploring the dominant frequency for the permeability enhancement technology of coal resonance excited by vibration wave，with the aid of an independently built coal natural frequency test system，the three-dimensional natural frequencies of different-rank（high，medium and low）dried cubic coal samples were tested and analyzed according to the test principle of the hammering method.The results showed that the Hanning window was suitable for fast Fourier transform analysis on vibration signals，as it could accurately identify the frequency corresponding to the spectral peak and thus directly obtained the natural frequency of coal.The hammering force only affected the acceleration amplitude of vibration signals，barely affecting the natural frequency of coal.For the same coal sample，the natural frequency of the plane parallel to bedding was larger than that perpendicular to bedding，and the natural frequencies of two planes perpendicular to bedding were slightly different.Influenced by factors such as coal matrix and mineral content，different-rank coal samples were endowed with varying mechanical properties，which was the main reason for the differences in their natural frequencies.The research results were expected to provide theoretical basis for the application of the permeability enhancement technology of coal resonance excited by vibration wave.

Key words:coal body;bedding;coal rank;vibration signal;natural frequency

 基于层理和煤阶影响的煤体固有频率特征研究_魏建平.pdf