Experimental study on tensile mechanical characteristics of pre-impact damaged white sandstone
ZHU Chuanqi
TANG Lupei
WANG Lei
CHEN Lipeng
YANG Zhenyu
JIN Kang
XIAO Qiang
Abstract：To investigate the influence of pre-impact damage on the tensile mechanical charac-teristics of white sandstone,this study first prepared rock specimens with varying damage de-grees using a Split Hopkinson Pressure Bar(SHPB)impact experimental system by adjusting impact air pressure.Subsequently,CT scanning tests were conducted on pre-damaged speci-mens to observe crack distribution patterns,followed by static Brazilian splitting tests inte-grated with Digital Image Correlation(DIC)technology to monitor surface morphology evolu-tion.The experimental results show that with increasing impact air pressure,the white sand-stone exhibited phased growth patterns:crack density,connected crack volume,and 3D con-nectivity initially increase slowly then rapidly,while the proportion of connected cracks shows linear growth and 3D fractal dimension increases rapidly and then slowly.Progressive structur-al transformation from intact to fragmented states occurs with rising impact air pressure.Ten-sile loading induces frequent stress drop phenomena in damaged specimens,with occurrence frequency positively correlated to impact intensity.The Brazilian splitting failure characteris-tics of white sandstone demonstrate distinct variations under different blasting gas pressures,with higher pressure levels leading to more concentrated zones of high strain.The tensile strength decreases exponentially while peak strain increases exponentially with ascending im-pact air pressure.These findings provide theoretical and experimental foundations for disaster prevention in deep coal mine stability control.
Keywords：white sandstoneimpact loadingBrazilian splittingfracture networkstress drops
Publication Date：2025-03-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 372-384 )