复杂结构接触面摩擦滑移力学过程的可视化分析方法

Quantitative characterization and visualization of the three-dimensional (3D) stress fields evolution in complex rock mass interfaces under frictional sliding is of great significance to reveal the mechanism of geological disasters such as fracturing fluid injection induced earthquake, stick-slip motion induced earthquake and deep fault slip induced strong rock burst. However, under frictional sliding, the invisible complex structures and mechanical processes in the natural rock mass interfaces constitute a complex problem of “black box”, which makes it hard for present study to quantitatively visualize the complex mechanical processes of frictional sliding in these interfaces, especially to characterize the distribution and evolution of the real contact zones and full-field stress that are critical to reveal the mechanism of frictional sliding. Therefore, in this study, by combining the techniques such as 3D shape measurement, 3D printing, image processing, digital photoelasticity, phase shifting and phase unwrapping, a new method to fabricate the transparent physical models of complex rock mass interfaces will be developed, a new shear loading device meeting the measurement of the real contact zones and full-field stress in complex interfaces will be designed, and the quantitative extraction methods of real contact zones and full-field stress in complex interface will be developed. Based on the evolution of the measured stress fields and real contact zones, a visualized analysis model for the mechanical processes of fractional sliding in complex interfaces will be developed that will provide a new idea for the research of frictional sliding mechanism.

定量表征与直观显示摩擦滑移过程中复杂岩体结构接触面内三维应力场的分布与演化，对揭示压裂液注入诱发地震、粘滑运动诱发地震、深部断层滑移诱发的强冲击矿压等灾害的机理具有重要意义。然而，天然接触岩体摩擦滑移时不可见的接触面结构和力学过程，构成了一个复杂的“黑箱”问题，使得当前研究难以定量可视化地表征复杂接触面摩擦滑移的力学过程，特别是精确表征对摩擦滑移机理分析至关重要的真实接触区域和全场应力的分布和演化。因此，本研究拟借助三维形貌测量、3D打印、图像处理、数字光弹性、相移和相位解包裹等技术，发展一种新的复杂岩体接触面透明物理模型制备方法，设计能够兼顾整个复杂接触面内真实接触区域和全场应力分布测量的剪切加载装置，发展复杂接触面内真实接触区域和全场应力的定量提取方法，建立复杂结构接触面摩擦滑移力学过程的可视化分析力学模型，为摩擦滑移破坏机理的分析提供新的思路和方法。

定量表征与直观显示摩擦滑移过程中复杂岩体结构接触面内三维应力场的分布与演化，对揭示压裂液注入诱发地震、粘滑运动诱发地震、深部断层滑移诱发的强冲击矿压等灾害的机理具有重要意义。然而，天然接触岩体摩擦滑移时不可见的接触面结构和力学过程，构成了一个复杂的“黑箱”问题，使得当前研究难以定量可视化地表征复杂接触面摩擦滑移的力学过程，特别是精确表征对摩擦滑移机理分析至关重要的真实接触区域和全场应力的分布和演化。因此，本研究通过CT、激光扫描等三维结构测量技术，获取了天然岩体模型接触面形貌数据，建立了直观显示复杂接触面结构的数字模型；结合以应力双折射透明树脂材料为打印原材料的3D打印技术，实现了与天然岩体接触面复杂结构一致的三维透明物理模型的制备，建立了接触面复杂结构的物理表征方法。研制了能够兼顾全场应力和真实接触区域测量的剪切加载装置，该装置通过可透光的石英材料对模型进行加载，保证了接触面法向的透光性，侧向施加剪切载荷，实现了接触面的剪切滑移加载, 基于接触面法向可透光的剪切加载装置，研究了透射光强与接触区域分布的对应关系，建立了真实接触区域光强阈值的判定方法，实现了真实接触区域分布的定量可视化。结合光弹性、DIC和云纹法，发展了一种表征3D打印复杂结构模型中全场应力和应变的方法，模型采用一种高度透明的无色材料打印，测试模型表面的散斑和光栅采用半透明的洋红色材料打印，两种打印材料均具有暂时双折射效应，满足光弹性应力测量的要求。本项目研究成果为建立复杂结构接触面摩擦滑移力学过程的可视化分析模型揭示摩擦滑移破坏机理提供新的思路和方法。