摘要
为探究冲击荷载条件下煤岩组合工程体的动力学响应特征,通过室内试验测得单一煤、岩的基本力学参数,为煤、岩体HJC模型材料参数的选取提供依据。在材料模型有效性验证的基础上,采用LS-DYNA显式动力学软件研究了不同冲击荷载、冲击方向及加载角度条件下煤岩组合体动态劈裂过程中的应力波传播规律、变形破坏过程及破坏特征。结果表明:(1)在不同冲击方向作用下,R-C与C-R组合体的应力波波形基本相同,但应力幅值略有差异,对比发现入射波幅值基本相等,但R-C组合体的反射波幅值偏大,透射波应力幅值偏小,随着冲击荷载的增大,差异性逐渐减小;(2)在不同冲击荷载作用下,煤岩组合体在劈裂过程中以煤体部分破坏为主,且组合体中煤体部分总是在交界面远处先产生宏观裂隙,而岩体部分则多在交界面近处先起裂破坏;(3)当冲击荷载较小时,C-R与R-C组合体的破坏形态基本相同,以拉伸、剪切破坏为主,随着冲击荷载的增大,组合体的破坏程度加剧,破坏形态的差异性也更明显;(4)提出了一种以单元损伤失效数量为评价指标的方法来定量分析组合体的破碎程度,从数据的变化规律发现,组合体在加载角度为45°时破坏最剧烈。
In order to investigate the dynamic mechanical characteristics of coal-rock composite engineering body under impact load,the basic mechanical parameters of pure coal and pure rock were obtained by laboratory tests for determining the parameters of HJC model.Based on the validity verification of the material model,LS-DYNA was employed to study the stress wave propagation features,failure process and failure characteristics of coal-rock combination bodies in dynamic splitting process considering the effects of impact loads,impact directions and loading angles.The results showed that:(1)the stress wave shapes of R-C and C-R samples are almost the same for different impact directions,but the stress amplitudes are slightly different.The comparison results showed that the incident wave amplitudes are similar,but for R-C samples,the amplitude of reflected wave is larger while that is smaller of transmitted wave.The difference gradually decreases with the increasing impact loads.(2)Under the action of different impact loads,the coal part is mainly damaged in the process of splitting,and the cracks generally appear in the coal part far from the interface,while the rock part commonly is damaged at the near side of the interface.(3)The failure modes of C-R and R-C samples are similar and mainly tensile and shear when the impact load is relatively low.The damage degree of the combination body is aggravated with increasing load,and the difference of failure modes becomes more obvious.(4)A method using the number of failure elements as an evaluation index is proposed to quantitatively analyze the breakage degree of the combination bodies.According to the numerical simulation results,the combination body damaged most seriously for the loading angle of 45°.
作者
马泗洲
刘科伟
郭腾飞
黄晓辉
周占星
MA Sizhou;LIU Kewei;GUO Tengfei;HUANG Xiaohui;ZHOU Zhanxing(School of Resources and Safety Engineering,Central South University,Changsha 410083,Hunan,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2022年第5期126-138,共13页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(51974360)。
关键词
煤岩组合体
动态劈裂
HJC模型
破坏特征
破坏过程
coal-rock combination body
dynamic splitting
HJC model
failure characteristics
failure process
