CAJ | 학술논문

通过MTS810材料测试系统及AE21C声发射检测仪对山东临沂花岗岩在20℃~800℃单轴压缩下的声发射特征进行试验研究,分别分析升温过程中花岗岩振铃计数率随时间的变化规律以及加载过程中花岗岩的声发射特征参量与应力–应变之间的关系.研究表明:升温及加载过程中,花岗岩声发射振铃计数率随着温度升高而增大,声发射活动也变得更频繁;其声发射参量在400℃~800℃高温后与高温下有较大差别,高温后的声发射参量明显低于高温下,岩样内部裂纹较少以致高温后花岗岩的强度等力学指标要优于高温下;各温度段高温下声发射振铃累计数都要高于高温后,尤其在800℃时,两者相差超过1倍;800℃前花岗岩岩样主要呈劈裂和剪切破坏为主的脆性破坏,未出现强烈的塑性破坏;高温使储存的能量显著增多并加速能量耗散,能量的耗散和弹性能的释放使岩石的强度减小,宏观裂纹增多并最终破坏.
통과MTS810재료측시계통급AE21C성발사검측의대산동림기화강암재20℃~800℃단축압축하적성발사특정진행시험연구,분별분석승온과정중화강암진령계수솔수시간적변화규률이급가재과정중화강암적성발사특정삼량여응력–응변지간적관계.연구표명:승온급가재과정중,화강암성발사진령계수솔수착온도승고이증대,성발사활동야변득경빈번;기성발사삼량재400℃~800℃고온후여고온하유교대차별,고온후적성발사삼량명현저우고온하,암양내부렬문교소이치고온후화강암적강도등역학지표요우우고온하;각온도단고온하성발사진령루계수도요고우고온후,우기재800℃시,량자상차초과1배;800℃전화강암암양주요정벽렬화전절파배위주적취성파배,미출현강렬적소성파배;고온사저존적능량현저증다병가속능량모산,능량적모산화탄성능적석방사암석적강도감소,굉관렬문증다병최종파배.
The laboratory tests are made for studying characteristics of acoustic emission(AE) of granite from Linyi in Shandong province at 20℃ to 800℃ using hydraulic-pressure servo testing system MTS810 and acoustic emission instrument AE21C. The relationship between ringdown count rate of granite and time as well as the relationship between AE parameters and stress-strain curves due to uniaxial compression loading are analyzed under different temperatures. Studies have shown that ringdown count rate rises and AE activity becomes more frequent with temperature increases both in the processes of heating and loading. AE parameters are quite different at and after the high temperature,of which AE parameters after high temperature are significantly lower than that at high temperature;and internal cracks are fewer resulting in that mechanical properties at high temperature are superior to that after high temperature. Ringdown cumulative count of granite at high temperature is higher than that after high temperature;especially at 800 ℃ when there is more than a doubled difference. The high temperature causes a significant increase in energy and accelerating the energy dissipation. The granite specimens showed brittle failure such as splitting and shear failure which did not appear strong ductile failure. The strength of the rock decreases and macroscopic cracks increase due to energy dissipation and elastic energy release which eventually cause deformation and failure of granite.