不同加载模式下岩石声发射及其分形特征分析
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摘要
利用MTS815 Flex Test GT岩石力学试验设备和PCI-2 AE实时三维定位监测系统,对灰岩进行单轴压缩和巴西劈裂损伤破坏过程中声发射事件分形特征进行了研究。结果表明,不同的声发射特征可反映岩石在不同加载方式下的声发射内部活动特性和内部破裂过程;劈裂加载条件下的声发射分形维数普遍大于单轴加载条件,单轴加载条件下的声发射活动性强于劈裂加载条件,劈裂加载条件下岩石的破裂尺度较小,裂纹的扩展分布较均匀;不同加载条件下的破裂过程中,声发射分形维数整体上均呈现下降趋势,且在岩石试样破坏前下降到最低值,表明岩石失稳破坏是一个降维有序的过程。
The limestone samples are tested on MTS815 Flex Test GT rock mechanics test system under uniaxial compression condition and brazilian test condition,and the acoustic emission events are monitored by PCI-2 AE system during whole test process. The experimental results show that,( a) the characteristics of acoustic emission can reflect the internal activity characteristics and internal rupture process of rock under different loading modes;( b) the fractal dimension of acoustic emission under splitting loading is generally larger than that under uniaxial loading,which indicates that the acoustic emission activity under uniaxial loading is stronger than that under splitting loading,and under the condition of splitting loading,the fracture size of rock is smaller and the distribution of cracks is more uniform; and( c) the fractal dimension of acoustic emission shows a downward trend throughout the fracture process under different loading conditions,and it decreases to the lowest value before the rock specimen is destroyed,which indicates that the rock instability and failure is a process of dimensionality reduction.
The limestone samples are tested on MTS815 Flex Test GT rock mechanics test system under uniaxial compression condition and brazilian test condition,and the acoustic emission events are monitored by PCI-2 AE system during whole test process. The experimental results show that,( a) the characteristics of acoustic emission can reflect the internal activity characteristics and internal rupture process of rock under different loading modes;( b) the fractal dimension of acoustic emission under splitting loading is generally larger than that under uniaxial loading,which indicates that the acoustic emission activity under uniaxial loading is stronger than that under splitting loading,and under the condition of splitting loading,the fracture size of rock is smaller and the distribution of cracks is more uniform; and( c) the fractal dimension of acoustic emission shows a downward trend throughout the fracture process under different loading conditions,and it decreases to the lowest value before the rock specimen is destroyed,which indicates that the rock instability and failure is a process of dimensionality reduction.
引文
[1]秦四清.岩石声发射技术概论[M].成都:西南交通大学出版社,1993.
[2]LOCKNER D.The role of acoustic emission in the study of rock fracture[J].International Journal of Rock Mechanics and Mining Sciences&Geomechanics Abstracts,1993,30(7):883-899.
[3]MANDELBROT B B,AIZENMAN M.Fractals:form,chance and dimension[J].Physics Today,1979,32(5):65-66.
[4]MANDELBROT B B.The fractal geometry of nature[M].New York:W H freeman,1982.
[5]HIMURA N,SATO K,TAKAHASHI H.Fracture simulation of inhomogeneous materials and fractal characteristics of acoustic emissions and microcracks[J].Transactions of the Japan Society of Mechanical Engineers Part A,1994,573(60):1170-1175.
[6]BIANCOLINI M E,BRUTTI C,PAPARO G,et al.Fatigue cracks nucleation on steel,acoustic emission and fractal analysis[J].International Journal of Fatigue,2006,28(12):1820-1825.
[7]赵凯华.非线性物理导论[M].北京:北京大学非线性科学中心,1992.
[8]谢和平.分形-岩石力学导论[M].北京:科学出版社,1996.
[9]赵奎,王更峰,王晓军,等.岩石声发射Kaiser点信号频带能量分布和分形特征研究[J].岩土力学,2008,29(11):3082-3088.
[10]尹贤刚,李庶林,唐海燕,等.岩石破坏声发射平静期及其分形特征研究[J].岩石力学与工程学报,2009,28(S2):3383-3390.
[11]梁忠雨,高峰,蔺金太,等.单轴下岩石声发射参数的分形特征[J].力学与实践,2009,31(1):43-46.
[12]柴肇云,康天合,陈维毅,等.泥岩压剪破坏裂隙演化规律及其分形特征[J].岩石力学与工程学报,2011(S2):3844-3850.
[13]刘京红,姜耀东,祝捷,等.煤岩单轴压缩声发射试验分形特征分析[J].北京理工大学学报,2013,33(4):335-338.
[14]LO T,LEUNG H,LITVA J,et al.Fractal characterisation of seascattered signals and detection of sea-surface targets[J].IEE Proceedings F-Radar and Signal Processing,1993,140(4):243-250.
[2]LOCKNER D.The role of acoustic emission in the study of rock fracture[J].International Journal of Rock Mechanics and Mining Sciences&Geomechanics Abstracts,1993,30(7):883-899.
[3]MANDELBROT B B,AIZENMAN M.Fractals:form,chance and dimension[J].Physics Today,1979,32(5):65-66.
[4]MANDELBROT B B.The fractal geometry of nature[M].New York:W H freeman,1982.
[5]HIMURA N,SATO K,TAKAHASHI H.Fracture simulation of inhomogeneous materials and fractal characteristics of acoustic emissions and microcracks[J].Transactions of the Japan Society of Mechanical Engineers Part A,1994,573(60):1170-1175.
[6]BIANCOLINI M E,BRUTTI C,PAPARO G,et al.Fatigue cracks nucleation on steel,acoustic emission and fractal analysis[J].International Journal of Fatigue,2006,28(12):1820-1825.
[7]赵凯华.非线性物理导论[M].北京:北京大学非线性科学中心,1992.
[8]谢和平.分形-岩石力学导论[M].北京:科学出版社,1996.
[9]赵奎,王更峰,王晓军,等.岩石声发射Kaiser点信号频带能量分布和分形特征研究[J].岩土力学,2008,29(11):3082-3088.
[10]尹贤刚,李庶林,唐海燕,等.岩石破坏声发射平静期及其分形特征研究[J].岩石力学与工程学报,2009,28(S2):3383-3390.
[11]梁忠雨,高峰,蔺金太,等.单轴下岩石声发射参数的分形特征[J].力学与实践,2009,31(1):43-46.
[12]柴肇云,康天合,陈维毅,等.泥岩压剪破坏裂隙演化规律及其分形特征[J].岩石力学与工程学报,2011(S2):3844-3850.
[13]刘京红,姜耀东,祝捷,等.煤岩单轴压缩声发射试验分形特征分析[J].北京理工大学学报,2013,33(4):335-338.
[14]LO T,LEUNG H,LITVA J,et al.Fractal characterisation of seascattered signals and detection of sea-surface targets[J].IEE Proceedings F-Radar and Signal Processing,1993,140(4):243-250.