基于拉格朗日反分析法的砂岩动态力学特性  

Experiment on dynamic mechanical properties of sandstone based on Lagrangian inverse analysis method

作　　者：张子健 陈骏[1] 朱锐 余浩然 李冉鑫 张渊通 ZHANG Zijian;CHEN Jun;ZHU Rui;YU Haoran;LI Ranxin;ZHANG Yuantong(School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing,100083,China;School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)力学与土木工程学院,北京100083 [2]北京科技大学土木与资源工程学院,北京100083

出　　处：《爆炸与冲击》2025年第3期24-36,共13页Explosion and Shock Waves

基　　金：国家自然科学基金(51934001);国家重点研发计划(2021YFB3401501)。

摘　　要：为深入研究深部地层中砂岩在冲击荷载作用下的动态力学特性,建立了一种改进的霍普金森压杆实验系统,对灰砂岩长杆试件开展了不同加载速率的动态压缩实验,并结合高速数字图像相关技术(DIC)监测试件表面位移场和应变场的演化过程,探讨了灰砂岩在近场冲击加载下的拉伸破坏的规律。从DIC分析得到的位移场中提取出不同质点位移时程曲线,进行了拉格朗日反分析算法计算,获得了灰砂岩材料的全场应力-应变规律。结果表明:灰砂岩长杆试件以拉伸破坏为主,且出现了近加载端破碎、远离加载端层裂的现象;灰砂岩长杆试件的动态抗压强度因子随应变率增大而增大,有明显的应变率效应;随着加载速率升高,各测点应力峰值与应变峰值均呈增大趋势;在同一加载速率下,灰砂岩长杆的应力-应变曲线呈现出近端测点曲线包络远端测点曲线的现象。To investigate the dynamic mechanical properties of sandstone in deep strata under impact loads,an improved Hopkinson pressure bar experimental system was established.The traditional Hopkinson pressure bar’s transmission rod was replaced with a long rod specimen made of gray sandstone to better simulate deep geological conditions.Point spalling treatment was applied to the specimen,and strain gauges were meticulously affixed at critical measurement points.Dynamic compression experiments were meticulously conducted on the gray sandstone long rod specimen at various loading rates(9.57,14.78,19.32 and 27.60 m/s).Utilizing high-speed digital image correlation(DIC)technology,the evolution of displacement and strain fields on the surface of the specimen throughout each test was closely monitored.This advanced technique enabled a detailed exploration of how the gray sandstone responded to near-field impact loading,particularly focusing on its tensile failure characteristics.Employing the Lagrangian inverse analysis method,displacement-time curves for different mass points derived from the DIC analysis of displacement fields were extracted.These curves provided critical data to compute the stressstrain behavior of the gray sandstone material under dynamic loading conditions.The study reveals several key findings:the gray sandstone long rod specimen predominantly exhibits tensile failure,with distinct patterns of fragmentation near the loading end and layer cracking away from it.Moreover,the dynamic compressive strength factor of the gray sandstone long rod specimen shows a notable increase with higher strain rates,indicating a significant strain rate effect.Correspondingly,both stress and strain peaks observe an upward trend at various measurement points with increasing loading rates.Remarkably,under identical loading rates,stress-strain curves of the gray sandstone long rod specimen exhibit a unique phenomenon where curves from measurement points closer to the loading end envelop those from points farther away.This ob

关 键 词：动态力学特性 数字图像相关法 拉格朗日反分析 砂岩 动态强度增强因子 

分 类 号：O347.3[理学—固体力学]