层状千枚岩三点弯曲试验的断裂破坏分析

Fracture Failure Analysis of Layered Phylite by Three-point Bending Test

为研究层状千枚岩的断裂破坏规律,通过加工0°、15°、30°、45°、60°、75°、90°共7种不同层理倾角的中心直切槽半圆盘试样,开展室内三点弯曲试验,分析了不同层理倾角Ⅰ型断裂韧度及断裂破坏模式,并基于声发射系统,分析了不同层理倾角层状千枚岩断裂破坏过程的声发射响应特性。结果表明:层理倾角由0°~90°的变化过程中,Ⅰ型断裂韧度逐渐增大,峰值载荷及峰值位移也呈增大趋势;层理倾角为0°时,发生张拉破坏,为15°~45°时,剪切破坏占主导,为60°~90°时,张拉破坏占主导;不同层理倾角层状千枚岩断裂破坏过程声发射响应,在临近破坏荷载时,瞬时振铃信号均明显比较活跃。

To study the fracture failure law of layered phyllite,a three-point bending test is carried out to analyze the mode Ⅰ fracture toughness and fracture failure mode of different bedding inclination angles by processing the central straight cut groove half disk samples with 7 different bedding inclination angles of 0°,15°,30°,45°,60°,75and 9o.Based on the acoustic emission system,the acoustic emission response characteristics of layered phyllite fracture process with different bedding angles are analyzed.The results show that:during the change of bedding inclination angle from 0°to 90°,the type Ⅰ fracture toughness gradually increases,and the peak load and peak displacement also show an increasing trend;when the bedding inclination angle is O°,tensile failure occurs;when the bedding inclination angle is between 15 and 45,shear failure dominates;when the bedding inclination angle is between 60°and 9o,tensile failure dominates;the acoustic emission response of layered phyllite with different bedding inclination angles during fracture process is obviously active when the failure load is near.