摘要
天然岩石普遍存在孔洞缺陷,为探究含孔洞岩样在冲击荷载作用下的力学特性和能量演化机理,先采用有限元软件ANSYS/LS-DYNA与Holmquist-Johnson-Cook(HJC)本构模型,对含不同尺寸的圆形和方形开孔岩样进行动态压缩模拟研究。接着,分析了孔洞形状与孔洞面积对岩样的强度和变形特征的影响,并考察了不同类型开孔岩样的裂纹发展与破坏特征。最后,阐释了不同类型岩样在冲击破坏过程中的能量转化机制。结果表明:含孔洞岩样的峰值应力和弹性模量均低于完整岩样,且随孔洞面积的增大分别呈指数和线性函数衰减;在冲击荷载下,含孔洞岩样的开裂时间早于完整岩样,岩样的破碎程度与孔洞面积呈正相关,且在同样孔洞面积下方形孔洞岩样力学性能劣化比圆形孔洞岩样更剧烈;随着孔洞面积的增大,岩样的透射能逐渐减小,耗散能逐渐增大,圆形和方形孔洞岩样的能耗密度均呈线性增长趋势。孔洞对岩样的劣化作用明显,且方形孔洞劣化强于圆形孔洞,能量演化规律与破坏模式密切相关。研究成果可为动态载荷下岩体工程建设及防灾减灾等提供有价值的参考。
Natural rocks commonly contain void defects.To investigate the mechanical response and energy evolution mechanisms of perfortated rocks under impact load,dynamic compression simulations were first conducted using the finite element software ANSYS/LS-DYNA and the Holmquist-Johnson-Cook(HJC)constitutive model.Numerical models featured rock samples containing circular and square holes of varying sizes.Then,the influence of hole geometry(shape and area)on the sample strength,deformation characteristics and crack development pattens were analyzed.Finally,the energy conversion mechanisms during the impact-induced failure for various types of rock samples were elucidated.The results show that the peak stress and elastic modulus of perforated samples are consistently lower than those of intact samples,exhibiting exponential and linear decreases respectively with increasing hole area.Under impact load,the perforated samples initiate cracking earlier than the intact sample.Sample fragmentation degree correlates positively with hole area.Square hole induce significantly stronger deterioration in mechanical properties than circular hole of equivalent area.Transmitted energy decreases gradually while the dissipated energy increases progressively with larger hole area.Energy consumption density increase linearly for the samples with both hole shapes.Hole-induced deterioration is pronounced,with square hole exhibiting stronger effects than circular hole.Energy evolution is closely linked to the damage patterns of samples.These results provide valuable references for rock engineering construction and disaster prevention/mitigation under dynamic loading conditions.
作者
孙少帅
王志亮
汪书敏
SUN Shaoshuai;WANG Zhiiang;WANG Shumin(School of Civil Engineering,Hefei University of Technology,Hefei,Anhui 230009,China)
出处
《水文地质工程地质》
北大核心
2025年第5期150-159,共10页
Hydrogeology & Engineering Geology
基金
国家自然科学基金项目(12272119,U1965101)。
关键词
穿孔岩石
孔洞几何
冲击荷载
动力响应
能量演化
perforated rock
hole geometry
impact load
dynamic response
energy evolution
作者简介
第一作者:孙少帅(2000-),男,硕士研究生,主要从事岩石动态损伤机理研究。E-mail:1523658302@qq.com;通讯作者:王志亮(1969-),男,博士,教授,博导,研究方向为岩石动力学。E-mail:cvewzL@hfut.edu.cn。
