单轴循环加卸载岩石非均匀变形演化特征

Properties of non-uniform deformation evolution of rock under uniaxial cyclic loading and unloading

  • 摘要: 为了研究循环加卸载下岩石材料的力学响应机制,开展了花岗岩试件单轴循环加卸载非均匀变形演化试验研究。采用CCD相机对试验过程中试件的变形图像进行采集,基于数字散斑相关方法分析了循环加卸载过程中试件的非均匀变形、局部化影响特征参数演化规律。研究发现:随着循环次数的增加,非均匀变形现象越来越明显;非均匀变形统计指标Sw随着加载应力的增大而增大,随着循环次数的增加而加剧;当试件出现局部化现象后,后续循环随着应力的增大及循环次数的增加,其挤压位移和局部化带影响宽度皆有所增大。

     

    Abstract: In order to study the mechanic responding mechanism of rock materials under cyclic loading and unloading, uniaxial cyclic loading and unloading tests were carried out to investigate the non-uniform deformation evolution processes of granite specimens. The deformation images of specimens during the tests were collected by CCD camera and based on the digital speckle correlation method,the non-uniform deformation,the evolution laws of the characteris- tic parameters of the localization during cyclic loading and unloading were analyzed. The research results show that: With the increase of cycle numbers,the non-uniform deformation is more and more obvious. The statistical index Sw of non-uniform deformation increases with the increase of loading stress,and increases with the increase of cycle num- bers. After the localization of a specimen appears,the extrusion displacement and the influence width of the localization band all increase with the increase of stress and cycle numbers in the subsequent cycles.

     

/

返回文章
返回