摘要
通过对砂岩试件等荷载循环加卸载试验,探究了砂岩试件的变形特性及塑性滞回环演化特征。结果表明:加载终点与卸载终点应变值均随着循环数有所增加,每一次循环均产生了一定的塑性变形,后四次循环新产生的塑性变形远小于初始循环,且随着循环数增加变形呈逐渐减少的趋势,最终试件被逐步压实,呈现出应变硬化现象。依据滞回环位置指标,发现塑性滞回环随着循环数增加逐渐右移,滞回环面积大小与应变值相关,循环加卸载终点的应变值越大,滞回环面积则越大,滞回环面积随循环数增加逐渐增大。
Through constant and cyclic loading and unloading tests on sandstone specimens, the characteristics of deformation and the plastic loop evolution of sandstone specimens are explored.The results show that the strain values in the end point of loading and unloading are increased with the increase of cycle number, a certain plastic deformation occurred in each cycle, where the later four cycles is far less than the initial cycle, and the deformation decreases gradually with the increase of the cycle number.Finally, specimens are gradually compacted, showing a strain hardening phenomenon.On the basis of the hysteresis loop position index, the plastic loop shift to the right and the areas of hysteresis loops are increased with the increase of cycle number.The area of hysteresis loop is related to the strain values, the grater the strain values in the end point of loading and unloading, the greater the area of hysteresis loop.
出处
《科学技术与工程》
北大核心
2017年第20期139-143,共5页
Science Technology and Engineering
基金
安徽省自然科学基金(1608085QE122)
河南省高等学校深部矿井建设重点学科开放实验室开放基金(2015KF-05)
中国博士后基金一等项目(2016M590558)
矿山地下工程教育部工程研究中心开放基金(2015KF04)资助
关键词
循环荷载
应变硬化
塑性滞回环
位置指标
cyclic loading
strain hardening
plastic hysteresis loop
location index
