【摘要】 利用实时全息干涉法、高分辨率数字摄像机与计算机图像处理系统相链接的三位一体化测量系统,连续动态观测了单轴受压砂岩、花岗岩和压剪受荷砂岩试样裂纹扩展与变形破坏过程;基于动态干涉条纹的定量分析,描述了岩石微裂纹孕育起裂、扩展与闭合的动态交替演化过程,计算了岩石裂纹扩展速度与蠕变扩展速率和裂纹面的扩展变形量与蠕变变形量,实现了岩石内部I型、I–II复合型、I–II–III复合型裂纹力学性状动态演变的有效判识。更多还原

【Abstract】 An integrated measuring system of real-time holographic interferometry layout linked charge coupled device(CCD) camera and computer graph process is experimentally used to continuously test and record the dynamic process of cracks growth and closure emerged in the whole stages of rock deformation and fracture on sand and granite specimens under unaxial compression and compressive-shear loading,respectively.The active interference fringe patterns captured from the holograms can reappear the development behaviour of rock cracks.Based on the fringes′ quantitative analysis and its calculation,the initiation and propagation of rock cracks as well as its growth and closure in different loading states are directly shown.And the spreading velocity and reformative quantity of rock cracks resulted from cracks growth or closure are given.In addition,the velocity of cracks creep extension and the quantity of cracks creep deformation are obtained.The movement of active fringes in space and time expounds the distribution of rock deformation field.Consequentlyt,he mechanical types of rock cracks can be distinguished effectively.Mode I crack perhaps keeps unchangeable or progressively transforms into mixed mode I–II or I–II–III crack under the different loading conditions,and crack modes are also varied with the evoluation and interaction of rock cracks,and the local deformation and inhomogeneous distributions of stress field become more intense in turn,which induces cracks growth and closure once again or secondary crack propagation.Actually the process of rock deformation and failure is the process of types alternation of rock crack in mechanics.更多还原