张开型节理角度和长度对类岩石材料动力学特性的影响

Effects of dip angle and length of open joints on dynamic properties of materials like rock

  • 摘要: 为探究冲击荷载作用下张开型节理对类岩石材料动态力学特性的影响,基于分离式霍普金森压杆实验装置(SHPB),研究完整试件和含不同角度和长度节理的水泥砂浆试件在动荷载下的应力波传播特征、峰值承载力、破坏形态,分析讨论了基于能量理论的损伤规律。结果表明:试件会形成一组沿轴向与节理面贯通的张拉裂纹面和一组几乎平行于试件端面的裂纹面;节理长度由5 mm增大到30 mm时,应力波的反射作用越明显,试件的峰值承载力越小,破坏产生的裂纹面越小,因而损伤也越小。当节理角度从0°增至90°时,应力波的反射作用越小,损伤越小;峰值承载力随节理角度增大先减小后增大,当节理角度为60°时,峰值承载力最小,当节理角度为90°时,峰值承载力最大。

     

    Abstract: In order to investigate the influence of tensioned joints on the dynamic mechanical properties of rock-like materials under impact loading, investigated the stress wave propagation characteristics, peak bearing capacity, damage pattern and damage law based on energy theory under dynamic loading for intact specimens and cement mortar specimens containing joints of different angles and lengths with the help of a split Hopkinson compression bar device.The results show that the specimens will be damaged by forming a set of tensile cracking surfaces along the axial direction through the joint surface and a set of cracking surfaces almost parallel to the end face of the specimen.Under the experimental loading rate, when the joint length increases from 5 mm to 30 mm, the more obvious the reflection effect on the wave, the smaller the peak bearing capacity of the specimen, and the smaller the damage.When the joint angle increases from 0° to 90°, the smaller the reflection effect on the stress wave, and the smaller the damage value of the specimen.The peak bearing capacity of the specimen decreases with the increase of the joint angle and then increases.When the joint angle is 60°, the peak bearing capacity of the specimen reaches the minimum, and when the joint angle is 90°, the peak bearing capacity of the specimen reaches the maximum.

     

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