煤矸冲击液压支架尾梁的振−声响应特性研究

Vibration-acoustic response characteristics of hydraulic support tail beam under coal-gangue impact

  • 摘要: 煤矸识别是降低综放开采原煤含矸率的核心技术。受井下作业环境中粉尘浓度高、能见度低、作业空间狭小等影响,现有基于图像、多光谱及射线、声音、振动加速度等单一识别特征的方法难以实现煤矸精准识别。针对该问题,以振动与声音信号为联合识别特征,采用COMSOL Multiphysics多物理场仿真软件,构建了煤矸冲击液压支架尾梁的振动−声学耦合模型,研究不同煤矸形状与入射角下煤矸冲击尾梁的动力学行为和声压频谱特征,得出振动加速度与声压信号分布规律。结果表明:矸石冲击尾梁时产生的应力、振动加速度幅值和声压信号特征均大于煤;球体、正方体、圆柱体煤矸颗粒冲击尾梁时产生的最大von Mises应力、振动加速度幅值和声压主频依次减小;随着煤矸入射角增大,煤矸冲击尾梁时的接触力、振动加速度峰值、声压信号频谱质心均呈下降趋势,且矸石冲击时响应衰减速率高于煤。研究结果为构建基于振动−声压多特征信号融合的煤矸识别策略提供了理论依据。

     

    Abstract: Coal-gangue identification is a key technology for reducing the gangue content in raw coal during fully mechanized top-coal caving mining. Affected by the high dust concentration, low visibility, and limited operating space in underground working environments, existing identification methods based on a single feature such as images, multispectral and ray signals, sound, or vibration acceleration have difficulty achieving precise coal-gangue identification. To address this problem, vibration and sound signals were used as joint identification features, and a vibration-acoustic coupling model of coal-gangue impacting the tail beam of a hydraulic support was established using COMSOL Multiphysics software. The dynamic behavior and sound pressure frequency spectrum characteristics of coal-gangue impacting the tail beam under different gangue shapes and incidence angles were investigated, and the distribution patterns of vibration acceleration and sound pressure signals were obtained. The results showed that the stress, vibration acceleration amplitude, and sound pressure signal characteristics generated by gangue impacting the tail beam were all greater than those generated by coal. When spherical, cubic, and cylindrical coal-gangue particles impacted the tail beam, the maximum von Mises stress, vibration acceleration amplitude, and main frequency of the sound pressure decreased successively. As the incidence angle of coal-gangue particles increased, the contact force, peak vibration acceleration, and spectral centroid of the sound pressure signal during impact with the tail beam all decreased, and the response attenuation rate during gangue impact was higher than that during coal impact. These findings provide a theoretical basis for constructing a coal-gangue identification strategy based on the fusion of multi-feature vibration-sound pressure signals.

     

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