采矿与安全工程学报 ›› 2013, Vol. 30 ›› Issue (3): 401-407.

• 论文 • 上一篇    下一篇

岩石试件SHPB劈裂拉伸试验中能量耗散分析

  

  1. 安徽理工大学矿山地下工程教育部工程研究中心,煤矿安全高效开采省部共建教育部重点实验室,安徽 淮南 232001
  • 出版日期:2013-05-15 发布日期:2013-05-15
  • 作者简介:平琦(1975-),男,安徽省淮南市人,讲师,博士,从事岩石动力学和爆破理论与技术方面的研究。 通信作者:马芹永 E-mail:qyma@aust.edu.cn Tel:0554-6668045
  • 基金资助:

    安徽高校省级自然科学研究重点项目(KJ2013A085);住房和城乡建设部科学技术项目(2012-K4-2);安徽省建设行业科学技术计划项目(2012YF-20)

Energy dissipation analysis of stone specimens in SHPB tensile test

  • Online:2013-05-15 Published:2013-05-15

摘要: 利用直径50 mm变截面分离式Hopkinson压杆(SHPB)试验装置,对厚径比0.5的煤矿砂岩巴西圆盘试件进行对径加载,采取改变驱动气压的方法实施不同加载速率的动态劈裂拉伸试验。研究了砂岩试件动态劈裂拉伸破坏过程中的能量构成和耗散特征;尝试从能量角度出发,对砂岩试件动态劈裂拉伸破坏形态、平均应变率效应和动态拉伸应力强度进行能耗分析;发现试件吸收能量绝大部分耗散于岩石的损伤演化和变形破坏,可以较好地反映砂岩试件在冲击载荷作用下的抗拉性能变化。结果表明:砂岩试件拉伸应力强度与吸收能量随平均应变率增加近似对数关系增加,表现出显著的应变率相关性。研究成果可为岩石类脆性材料动态拉伸力学性能研究提供参考。

关键词: 岩石力学, 巴西圆盘, 分离式Hopkinson压杆(SHPB), 能量耗散, 应变率效应

Abstract: Variable cross-section split Hopkinson pressure bar (SHPB) with a diameter of 50 mm is adopted to implement radial loading to the mine sandstone Brazilian disc, which has a thickness-diameter ratio of 0.5. Dynamic tensile tests at various loading rates are obtained by altering impact loading pressures. Through investigating energy composition and dissipation characteristics of sandstone specimens during the dynamic tensile failure process, this paper tries to analyze the failure forms, average strain rate effect and dynamic tensile strength from energy dissipation perspective. It is found that energy absorbed by specimen mostly dissipates in the damage evolution and deformation failure process, which corresponds well to the tensile performance of sandstone under dynamic loads. The results showed that tensile strength and absorbed energy increase logarithmically with the average strain rate, a remarkable strain rate correlation. The results can provide some reference for dynamic tensile performance research of rocklike brittle materials.

Key words: rock mechanics, Brazilian disc, split Hopkinson pressure bar(SHPB), energy dissipation, strain rate effect