循环载荷对红砂岩峰值强度影响的试验研究  

Test Research on Peak Intensity of Red Sandstone on Cyclic Loading

作　　者：郭隆仁 纪沛志 刘坤 秦楠[1] 王永岩[1] GUO Longren;JI Peizhi;LIU Kun;QIN Nan;WANG Yongyan(College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266100)

机构地区：[1]青岛科技大学机电工程学院,青岛266100

出　　处：《计算机与数字工程》2025年第3期882-888,906,共8页Computer & Digital Engineering

摘　　要：为研究循环载荷损伤对红砂岩峰值强度的影响,对红砂岩试件开展三种应力幅值下的循环加卸载破坏试验,取试件循环破坏前不同循环次数阶段进行单轴压缩试验得到其峰值强度,通过对其应变变化差值、平均动弹性模量、峰值破坏强度等参数的分析,研究试件在经历不同循环次数损伤后的强度变化规律,结合砂岩在低周期循环载荷下的疲劳方程,拟合得到三种不同应力幅值下进行试验的红砂岩损伤变量的表达式大致相似。结果表明:随着循环次数的增加,红砂岩试件峰值强度会呈现出先上升、后下降的规律,与应变变化差值呈负相关趋势;在被紧密压实后(20次)的砂岩试件进入应变硬化区,峰值强度最高可提升18.1%;在被压密的基础上继续进行循环载荷试验,试件会由于多次循环的疲劳损伤产生裂隙,动弹性模量产生波动,峰值强度也会因此有下降趋势。In order to study the influence of cyclic load damage on the peak strength of red sandstone,the red sandstone specimens are subjected to cyclic loading and unloading tests under three different stress amplitudes until failure.The peak strength of the specimen is obtained by uniaxial compression test at different cycles before cyclic failure.Through the analysis of the parameters such as the difference of strain change,the average dynamic elastic modulus of loading and unloading,and the peak failure strength of the specimen,the strength change law of the red sandstone specimen after different cycles of damage is studied.Combined with the fatigue equation of the sardstone under low-cycle loading,and the red sandstone specimens subjected to cyclic loading tests at three different stress amplitudes are obtained,and the expressions of the damage variables are roughly similar.The results show that with the increase of the number of cyclic loads,the peak strength of the red sandstone specimen will show an obvious law of first rising and then decreasing,which is negatively correlated with the difference in strain change,the sandstone specimen after being compacted(20 times)entering the strain hardening zone,the peak strength can be increased by up to 18.1%,if the cyclic load test is continued on the basis of being compacted,the specimen will have cracks due to fatigue damage of multiple cycles,the dynamic elastic modulus will fluctuate,and the peak strength will also tend to decline.

关 键 词：循环次数 低周期 等幅加载 红砂岩 峰值强度 

分 类 号：TU45[建筑科学—岩土工程]