| 377 | 2 | 227 |
| 下载次数 | 被引频次 | 阅读次数 |
为了探究动静组合加载条件下岩样长径比对其强度及破坏形态的影响，先基于岩石动力学理论，阐释了SHPB试验中应力波传播的基本规律。随后，采用ANSYS/LS-DYNA有限元软件，对6组不同长径比试样开展了动静组合加载数值模拟，深入分析其应力-应变响应与破坏形态的演化规律。研究结果表明：动静组合加载下试样应力-应变曲线大致分线弹性阶段、破坏阶段与峰后阶段；长径比越大，破坏阶段的“上凹”现象越显著；当长径比n>0.8时，应力-应变曲线峰后阶段出现回弹。围压相同时，不同轴压下试样峰值应力总体上随长径比的增大而增大。轴压在20 MPa条件下，当围压低于一定阈值时，大长径比试样峰值应力会更高；而当围压大于该阈值，峰值应力与长径比关系不甚明显；围压的增加会抑制长径比对峰值应力的影响。在不同动静组合加载条件下，试样均以剪切破坏为主，端面边缘易出现碎块脱落，侧面可观测到剪切裂纹；随着长径比的增大，试样破坏程度逐渐降低，其侧面剪切裂纹数量也趋于减少。
Abstract：To investigate the effect of aspect ratio on the strength and failure mode of rock sample under the combined dynamic and static loading conditions, the basic law of the stress wave propagation in split-Hopkinson pressure bar(SHPB) test was initially elucidated based on the rock dynamics theory. Subsequently, the ANSYS/LS-DYNA finite element numerical simulations were conducted on six groups of rock samples with different aspect ratios under the combined static and dynamic loading. The evolution laws of stress-strain responses and failure patterns were further analyzed. The results show that the stress-strain curves of the rock samples under the combined static and dynamic loading can be roughly divided into linear elastic stage, failure stage and post-peak stage. As the aspect ratio n increases, the concave phenomenon at the failure stage becomes more obvious, and the stress-strain curve rebounds at the post-peak stage once the aspect ratio n exceeds 0.8. When confining pressure is constant, the peak stresses of rock samples under different axial compression generally increase with the increase of the aspect ratio. When the axial compression is set as 20 MPa, a threshold of the confining pressure exists, where the peak stress of larger aspect ratio of rock sample is higher as the confining pressure is below it. However, it hardly varies with the aspect ratio when the confining pressure is over this threshold. An increase in the confining pressure can suppress the effect of the aspect ratio on the peak stress. Under the combined different static and dynamic loading, the rock samples mainly exhibit shear failure, with fragments falling off at the edge of the end faces and shear cracks observed on the sides. As the aspect ratio increases, the failure degree of rock samples gradually decreases and the number of lateral shear cracks tends to decrease.
[1] 戴俊.岩石动力学特性与爆破理论(第2版)[M].北京：冶金工业出版社，2014.DAI Jun.Dynamic behaviors and blasting theory of rock(The Second Edition)[M].Beijing:Metallurgical Indu-stry Press,2014.
[2] 巫绪涛，相福斌，张瑞乾，等.尺寸效应对岩石动态力学行为的影响研究[J].合肥工业大学学报，2021,44(10):1379-1384.WU Xutao,XIANG Fubin,ZHANG Ruiqian,et al.Study on the influence of size effect on dynamic mechanical behavior of rock[J].Journal of Hefei University of Technology,2021,44(10):1379-7384.
[3] 平琦，张号，苏海鹏.不同长度石灰岩动态压缩力学性质试验研究[J].岩石力学与工程学报，2018,37(S2):3891-3897.PING Qi,ZHANG Hao,SU Haipeng.Study on dynamic compression mechanical properties of limestone with different lengths[J].Chinese Journal of Rock Mechanics and Engineering,2018,37(S2):3891-3897.
[4] 郭鹏飞，李志康，彭岩岩，等.基于SHPB试验的多尺寸大理岩动态力学性能研究[J].金属矿山，2022,51(5):86-94.GUO Pengfei,LI Zhikang,PENG Yanyan,et al.Study on dynamic mechanical properties of multi-size marble based on SHPB test[J].Metal Mine,2022,51(5):86-94.
[5] 洪亮.冲击荷载下岩石强度及破碎能耗特征的尺寸效应研究[D].长沙：中南大学，2008.HONG Liang.Size effect on strength and energy dissipa-tion in fracture of rock under impact loads[D].Chang-sha:Central South University,2008.
[6] 洪亮，李夕兵，马春德，等.岩石动态强度及其应变率灵敏性的尺寸效应研究[J].岩石力学与工程学报，2008,27(3):526-533.HONG Liang,LI Xibing,MA Chunde,et al.Study on size effect of rock dynamic strength and strain rate sensitivity[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(3):526-533.
[7] 高富强，杨军，刘永茜，等.岩石准静态和动态冲击试验及尺寸效应研究[J].煤炭科学技术，2009,37(4):19-22,68.GAO Fuqiang,YANG Jun,LIU Yongqian,et al.Research on rock parastatic and dynamic impact test and size effect[J].Coal Science and Technology,2009,37(4):19-22,68.
[8] HU ZY,XU LX,QIAN YJ,et al.Numerical simulation of size effect of defective rock under compression condition[J].Scientific Reports,2023,13(1):420-428.
[9] 解北京，栾铮，陈冬新，等.不同长径比煤样动力学特征及本构模型[J].矿业科学学报，2023,8(2):190-201.XIE Beijing,LUAN Zheng,CHEN Dongxin,et al.Dynamic characteristics and constitutive model of coal samples with different length diameter ratio[J].Journal of Mining Science and Technology,2023,8(2):190-201.
[10] XU ZY,WU YX,LIU X,et al.Energy dissipation and stress equilibrium behavior of granite under dynamic impact[J].Applied Sciences,2022,12(12):6107-6107.
[11] 张号，平琦，苏海鹏.不同长径比石灰岩动态压缩SHPB试验研究[J].煤炭科学技术，2018,46(8):38-43.ZHANG Hao,PING Qi,SU Haipeng.Study on dynamic compression SHPB test of limestone with different length diameter ratios[J].Coal Science and Technology,2018,46(8):38-43.
[12] 李地元，肖鹏，谢涛，等.动静态压缩下岩石试样的长径比效应研究[J].实验力学，2018,33(1):93-100.LI Diyuan,XIAO Peng,XIE Tao,et al.On the effect of length to diameter ratio of rock specimen subjected to dynamic and static compression[J].Journal of Experimental Mechanics,2018,33(1):93-100.
[13] ZHAO ZH,YANG GS,LI GQ,et al.Effects of the length-diameter ratio on the dissipation energy in the process of rock deformation and failure[J].Energy Reports,2022,8(2):13369-13375.
[14] 王磊，袁秋鹏，谢广祥，等.冲击载荷下煤样能量耗散与破碎分形的长径比效应[J].煤炭学报，2022,47(4):1534-1546.WANG Lei,YUAN Qiupeng,XIE Guangxiang,et al.Length diameter ratio effect of energy dissipation and fractals of coal samples under impact loading[J].Journal of China Coal Society,2022,47(4):1534-1546.
[15] 张盛，王峥，张旭龙，等.不同尺寸砂岩动态力学性质和应力平衡性的试验研究[J].爆炸与冲击，2022,42(10):22-38.ZHANG Sheng,WANG Zheng,ZHANG Xulong,et al.Rock dynamic mechanical properties and dynamic stress balance of sandstone specimens with different sizes[J].Explosion and Shock Waves,2022,42(10):22-38.
[16] GONZáLEZ-FERNáNDEZ M A,ESTéVEZ-VENTOSA X,GA-RCíA-BASTANTE F,et al.Study of size effects on the peak and residual strength of intact and artificially fissured granite samples[A].Rock and Fracture Mechanics in Rock Engineering and Mining IOP Conference Series:Earth and Environmental Science[C].Helsinki:IOP Publishing Ltd,2022.
[17] 孙卓越，吴拥政，孙久政，等.三维动静加载下煤样动态变形模量长径比效应[J].采矿与岩层控制工程学报，2022,4(4):043021.SUN Zhuoyue,WU Yongzheng,SUN Jiuzheng,et al.Length-to-diameter ratio effect of dynamic deformation modulus of coal samples under three-dimensional dynamic and static loading[J].Journal of Mining and Strata Co-ntrol Engineering,2022,4(4):043021.
[18] 潘博，汪旭光，郭连军，等.组合静载条件下SHPB试件长径比优选研究[J].爆破，2022,39(3):1-9.PAN Bo,WANG Xuguang,GUO Lianjun,et al.Optimization of slenderness ratio of SHPB specimens under combined static load[J].Blasting,2022,39(3):1-9.
[19] 李夕兵，李地元，郭雷，等.动力扰动下深部高应力矿柱力学响应研究[J].岩石力学与工程学报，2007,26(5):922-928.LI Xibing,LI Diyuan,GUO Lei,et al.Study on mechanical response of highly-stressed pillars in deep mining under dynamic disturbance[J].Chinese Journal of Rock Mechanics and Engineer-ing,2007,26(5):922-928.
[20] 杨辉.单轴冲击荷载下花岗岩力学特性与数值模拟研究[D].合肥：合肥工业大学，2020.
[21] 聂铮玥.三种典型岩石材料的RHT模型参数研究[D].长沙：国防科技大学，2021.
[22] 邱薛，刘晓辉，胡安奎，等.煤岩动态RHT本构模型数值模拟研究[J/OL].煤炭学报，https://doi.org/10.13225/j.cnki.jccs.2023.0540,2023-12-27.QIU Xue,LIU Xiaohui,HU Ankui,et al.Research on numerical simulation of coal dynamic RHT constitutive model[J].Journal of China Coal Society,https://doi.org/10.13225/j.cnki.jccs.2023.0540,2023-12-27.
[23] 李洪超.岩石RHT模型理论及主要参数确定方法研究[D].北京：中国矿业大学(北京),2016.
基本信息:
DOI：10.13532/j.jmsce.cn10-1638/td.2024.04.012
中图分类号:TU45
引用信息:
[1]王诗杰,王志亮,封陈晨,等.动静组合加载下长径比对岩样峰值应力与破坏形态影响研究[J].采矿与岩层控制工程学报,2024,6(04):130-140.DOI:10.13532/j.jmsce.cn10-1638/td.2024.04.012.
基金信息:
国家自然科学基金资助项目(12272119,U1965101)