中南大学学报（自然科学版）2024，Vol.55Issue(9)：3469-3479,11.DOI:10.11817/j.issn.1672-7207.2024.09.020
动静荷载下煤岩体应力波传播与衰减特征
Stress wave propagation and attenuation of coal rock masses under static and dynamic loads
摘要
Abstract
Firstly,the split Hopkinson pressure bar(SHPB)experimental system was employed to conduct impact tests on coal rock samples of short length(50 mm)and long length(300 mm)at various strain rates and different propagation distances,with strain gauges attached to various positions on the long samples.Secondly,a self-developed dry-coupled ultrasonic testing system was utilized to conduct ultrasonic tests at multiple stress levels and frequencies.Finally,the energy loss patterns during stress wave propagation in coal rock,as well as the attenuation patterns of high-frequency and low-frequency waves,were revealed.The results show that the peak values of incident,reflected and transmitted stress waves in the impact tests increase with the increase of strain rate.However,as the wave frequency increases with the increase of strain rate,high-frequency waves are more prone to attenuation when microscopic structural planes is traversed,resulting in a linear decrease in the transmission coefficient with the increase of strain rate.The transmitted waves exhibit a rapid attenuation within 300 mm of propagation,with a decay rate of up to 30%,followed by an approximately exponential attenuation pattern with further distance.In contrast,due to their small vibration amplitude and high frequency,ultrasonic waves rapidly attenuate when the propagation distance reaches 75 mm,with subsequent attenuation gradually leveling off.High frequencies are more likely to interact with the microscopic structure of coal rock and be absorbed,leading to faster attenuation of high-frequency waves with propagation distance.A linear relationship exists between frequency and the attenuation of wave amplitude.关键词
应力波/超声波/煤岩体/波传播/冲击荷载/霍普金森压杆Key words
stress wave/ultrasonic wave/coal rock masses/wave propagation/impact loading/SHPB分类
矿业与冶金引用本文复制引用
金志豪,李远,栾亚伟,王春晓,周明..动静荷载下煤岩体应力波传播与衰减特征[J].中南大学学报（自然科学版）,2024,55(9):3469-3479,11.基金项目
国家重点研发计划项目(2022YFC2904102) （2022YFC2904102）
佛山市科技创新专项资金资助项目(BK21BE014)(Project(2022YFC2904102)supported by the National Key Research and Development Program of China （BK21BE014）
Project(BK21BE014)supported by the Foshan Science and Technology Innovation Special Fund Funding Project) （BK21BE014）
