非连续循环荷载作用下岩盐力学特性试验研究

发布时间：2018-01-05 11:17

本文关键词：非连续循环荷载作用下岩盐力学特性试验研究　出处：《岩土力学》2017年05期 　论文类型：期刊论文

【摘要】：运用多功能试验机首次开展岩盐非连续疲劳试验,研究了时间间隔作用下的岩盐的力学特性(包括变形和弹性常数)的演化规律。试验结果显示:(1)与常规疲劳情况不同,间隔疲劳过程中时间间隔后的循环产生的轴向残余应变总大于时间间隔前的残余应变,且径向和体积残余应变呈现出与轴向相同的规律。(2)时间间隔后的循环内弹性模量总体大于时间间隔前的循环内弹性模量,但泊松比随时间间隔变化不明显,时间间隔前、后均呈相似的上升趋势。(3)间隔疲劳过程中的时间间隔对塑性变形的积累有加速效应,时间间隔越长,疲劳过程中残余应变积累越快,岩盐疲劳寿命越短。(4)循环过程中无应力静置时间间隔的出现,为岩盐内部结构的整体调整提供了时空条件,有利于晶粒在残余应力作用下归位并产生新的滑移面,后续加载时晶粒回到原应力峰值对应位置将耗散更少能量,宏观上表现为塑性变形的加速积累,岩盐更容易发生疲劳破坏,疲劳寿命降低。
[Abstract]:The use of multi function test machine for the first time to carry out salt non continuous fatigue test, the study on the mechanical properties of rock salt under the action of the time interval (including the deformation and elastic constants) evolution. Test results showed that: (1) different from the conventional fatigue, the axial residual strain after the interval cycle generation interval of the fatigue process is always greater than that of the residual strain time interval before, and the residual strain and radial and axial volume showed the same rule. (2) the time interval after the cycle of the elastic modulus is greater than the time interval before the cycle but the elastic modulus, Poisson's ratio with time interval does not change significantly, time interval, and showed a similar upward trend. (3) the interval during fatigue time interval accumulation has accelerating effect on plastic deformation, the time interval is long, fatigue residual strain accumulated during the faster, the shorter fatigue life of rock salt. (4) cycle There in the process of stress free standing time interval, provided the conditions for the whole time to adjust the internal structure of rock salt, grain in residual stress and produce a new homing slip surface, subsequent loading grain back to the original position corresponding to the peak stress will be less energy dissipation, exhibited accelerated accumulation of plastic deformation of rock salt, more prone to fatigue failure, fatigue life decreases.

【作者单位】：重庆大学煤矿灾害动力学与控制国家重点试验室;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金项目(No.51604044,No.41672292,No.51574048) 中央高校基本科研业务费专项资金资助(No.106112016CDJZR245518)~~
【分类号】：TU452
【正文快照】： 2.中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071)2016年是“十三五”规划的开局之年,在能源方面,必须按照党中央、国务院的决策部署,从根本上解决影响我国能源科学发展的长期性、深层次问题。能源规划中重点提到应“加强石油替代和储备应急能力

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