北京大学学报（自然科学版）2025，Vol.61Issue(5)：839-852,14.DOI:10.13209/j.0479-8023.2025.078
不同加载速率下青砂岩抗拉特征及能量耗散规律研究
Tensile Properties and Energy Consumption Law in Green Sandstone under Different Loading Rates
摘要
Abstract
In order to investigate the tensile characteristics and energy dissipation laws of green sandstone under different loading rates,the macro-micro mechanical response relationship of green sandstone was established by combining indoor experiments and micro parameter calibration.The mechanical properties,fracture characteristics,crack propagation,and energy dissipation laws of green sandstone under different loading rates were studied using the particle flow code.The results are as follows.1)With the loading rate of 0.1 m/s as the boundary point,the maximum radial stress-strain of green sandstone exhibits a sequentially slow and rapid increasing trend,and the microelements formed after fracture accelerate to fracture again in accordance with the Brazilian splitting method.2)When the loading rate is less than 0.1 m/s,the tensile cracks in the green sandstone show the trend of slight fluctuations,and no shear cracks appear.When the loading rate is more than 0.1 m/s,tensile cracks increase rapidly and shear cracks begin to appear,but the number is relatively small.The propagation direction of crack is perpendicular or at a certain angle to the loading direction,and relatively less in the horizontal direction.There is a negative correlation between crack propagation time and loading rate.When the loading rate is 0.1～1 m/s,the propagation time of crack tends to be stable,with a range of 1.757-0.951 μs.3)When the loading rate is less than 0.1 m/s,except for significant fluctuations in kinetic energy,the dissipated energy basically shows a trend of small fluctuations.However,when the loading rate is more than 0.1 m/s,the dissipated energy increases rapidly.The energy loss(kinetic energy)accounts for the main part,while the energy used for crack propagation(damping energy and friction energy)is more than the energy used for crack generation(bond failure energy).This study not only reveals the characteristics of rock fracture and energy dissipation at the microscopic level,but also provides reference for the rational selection of loading methods in rock-crushing processes.关键词
青砂岩/加载速率/巴西劈裂/抗拉特征/颗粒流模拟/裂纹扩展/能量耗散/能量利用效率Key words
green sandstone/loading rate/Brazilian splitting/tensile properties/particle flow code/crack propa-gation/energy consumption/utilization efficiency of energy引用本文复制引用
赵环帅,潘永泰,乔鑫,王星宇,岳帆凯,黄嘉诚,李凯宁,马壮,郭彩玲..不同加载速率下青砂岩抗拉特征及能量耗散规律研究[J].北京大学学报（自然科学版）,2025,61(5):839-852,14.基金项目
国家自然科学基金(52074308)资助 （52074308）
