| 王智德,李杰,武海港,司莹莹,熊文,吝曼卿,刘奇.不同高应变率冲击荷载作用下混凝土试样的能量耗散分析[J].计算力学学报,2023,40(4):621~627 |
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| 不同高应变率冲击荷载作用下混凝土试样的能量耗散分析 |
| Energy dissipation analysis of concrete samples under impact loads of different high strain rates |
| 投稿时间：2021-12-26 修订日期：2022-03-29 |
| DOI：10.7511/jslx20211226001 |
| 中文关键词: 霍普金森试验 平均破碎尺寸 入射能 材料吸收能 平均应变率 |
| 英文关键词:Hopkinson's experiment average crushing size incident energy material absorption energy average strain rate |
| 基金项目:国家自然科学基金(51374163;52174085);武汉市城乡建设委员会科技计划项目(武城建[2017]12号-201740;武城建[2019]68号-201941);磷资源开发利用教育部工程研究中心开放基金(LKF202004)资助项目. |
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| 中文摘要: |
| 针对混凝土材料在冲击荷载作用下能量耗散和破碎程度关联性难确定的问题,采用分离式霍普金森压杆(SHPB)完成了混凝土试块冲击试验,通过对冲击后碎块的筛分试验和应力波传播过程中应变的测试,得到了试块的能量耗散规律和破碎特征。结果表明,(1) 入射应力波的加载时间约为380 μs,入射能、反射能和吸收能随冲击气压的增大而增大;同一气压下,反射能最早达到平衡; (2) 平均应变率越大,入射能和吸收能也越大;当平均应变率为300/s左右时,能量利用率为最低值; (3) 随着入射能的增加,吸收能的增长率越来越大,当入射能达到2100 J时,吸收能近乎线性增长; (4) 随冲击气压增大,试样由拉裂破坏逐渐转移为压碎破坏,且随着材料吸收能的增大,平均破碎尺寸越来越小。当吸收能大于700 J时,吸收能对试样的平均破碎尺寸减小的影响较小。 |
| 英文摘要: |
| Facing the problem that the correlation between the energy dissipation of concrete material under shock load and its degree of fragmentation is difficult to determine,a concrete block impact test was completed based on the split Hopkinson pressure bar (SHPB),and through screening the fragments after impact and testing the strain during stress wave propagation,the rule of the energy dissipation and characteristics of the block is found.The results show that:(1) The loading time of incident stress wave is about 380 μs,and the incident energy,reflected energy and absorbed energy increase with the impact pressure; at the same impact pressure,the reflected energy is the first to reach equilibrium. (2) The higher the average strain rate is,the higher the incident energy and absorbed energy are.When the average strain rate is about 300/s,the energy utilization rate is the lowest. (3) With the increase of incident energy,failure of the rate of increase of the absorbed energy becomes larger and larger.The absorbed energy increases almost linearly as the incident energy reaches 2100 J. (4) With the increase of the impact pressure,failure of the specimen gradually changes from tensile to crushing,and with the increase of absorbed energy,the average crushing size becomes smaller and smaller.When the absorbed energy is greater than 700 J,the absorbed energy has little influence on the reduction of the average crushing size of the sample. |
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