摘要
能量变化是材料各参数变化的本质特征。通过颗粒流模拟岩石单轴压缩试验,从细观力学角度分析能量转化、裂纹扩展及损伤演化规律。颗粒流利用细观颗粒的运动克服了宏观力学理论不易实现试件多裂纹破坏形态的缺点,以此研究能量变化更加合理。应力-应变各阶段能量与微裂纹及损伤存在着相互对应的发展关系。通过3种工况论证了宏-细观力学参数对应关系,采用最小二乘法拟合得出微裂纹与轴向应变呈幂次函数关系。采用割线模量定义损伤变量,取模量加速下降处(对应裂纹加速扩展)为损伤门槛,对应损伤阈值为0.158。3种工况下微裂纹数量与损伤呈线性发展关系,为损伤演化的深入研究提供参考。
Energy transmission is an essential feature of material. Uniaxial compression test is performed by particle flow code to study crack propagation, energy transmission and damage evolution. It's revealed to be more reasonable to research the energy through PFC, which overcomes the defect of macro mechanical theory and makes it possible to achieve multiple cracks failure form of specimen. In the compression process there is a one to one correspondence between cracks, energy and damage evolution. The relationship between macro-and micromechanical parameters is analyzed under three working conditions. It is concluded by least square fitting that microcracks are in power function with axial strain. Damage variable is defined with secant modulus. The accelerated decline of elastic modulus is taken as damage threshold which equals to 0.158. It has been proved that there is a linear regression relationship between damage and microcracks, so as to provide reference for further research on damage evolution.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第S1期94-100,共7页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51439008)
国家自然科学基金青年科学基金(No.41302239)
湖北省道路桥梁与结构工程重点实验室开放基金(No.DQJJ201313)
关键词
单轴压缩
颗粒流程序
能量转化
裂纹扩展
损伤演化
uniaxial compression
particle flow code
energy transformation
crack propagation
damage evolution
