Geomechanics and Engineering

Volume 22, Number 2, 2020, pages 187-196

DOI: 10.12989/gae.2020.22.2.187

Waveform characterization and energy dissipation of stress wave in sandstone based on modified SHPB tests

Yun Cheng , Zhanping Song , Jiefang Jin , Tong Wang , Tengtian Yang

Abstract

The changeable stress environment directly affect the propagation law of a stress wave. Stress wave propagation tests in sandstone with different axial stresses were carried using a modified split Hopkinson Pressure bar (SHPB) assuming the sandstone has a uniform pore distribution. Then the waveform and stress wave energy dissipation were analyzed. The results show that the stress wave exhibits the double peak phenomenon. With increasing axial stress, the intensity difference decreases exponentially and experiences first a dramatic decrease and then gentle development. The demarcation stress is σ/σc=30%, indicating that the closer to the incident end, the faster the intensity difference attenuates. Under the same axial stress, the intensity difference decreases linearly with propagation distance and its attenuation intensity factor displays a quadratic function with axial stress. With increasing propagation distance, the time difference decays linearly and its delay coefficient reflects the damage degree. The stress wave energy attenuates exponentially with propagation distance, and the relations between attenuation rate, attenuation coefficient and axial stress can be represented by the quadratic function.

Key Words

sandstone; axial stress; stress wave; waveform characterization

Address

PDF Viewer

Preview is limited to the first 3 pages. Sign in to access the full PDF.

Loading…