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冰川冻土 ›› 2003, Vol. 25 ›› Issue (4): 461-464.

• 寒区工程技术 • 上一篇    下一篇

冰煤断裂韧度的测试研究

张小鹏, 邢怀念, 黄诚, 刘维波, 李仑   

  1. 大连理工大学, 工程力学系, 辽宁, 大连, 116023
  • 收稿日期:2002-10-11 修回日期:2003-01-11 出版日期:2003-08-25 发布日期:2012-04-26
  • 作者简介:张小鹏(1955- ),男,辽宁大连人,副教授,1982年毕业于大连工学院,现主要从事实验力学方向研究.E-mail:liuwb@student.dlut.edu.cn
  • 基金资助:
    国家自然科学基金项目(50278010)资助

Experimental Study of the Fracture Toughness of Frozen Coal

ZHANG Xiao-peng, XING Huai-nian, HUANG Cheng, LIU Wei-bo, LI Lun   

  1. Department of Engineering Mechanics, Dalian University of Technology, Dalian Liaoning 116023, China
  • Received:2002-10-11 Revised:2003-01-11 Online:2003-08-25 Published:2012-04-26

摘要: 通过对冰煤在-30℃低温状态下的断裂韧度KIC的测试试验, 得出了在不同预制裂纹长度条件下冻结煤体的断裂韧度变化情况. 试验中制备了三点弯曲试样并制作了低温环境下的三点弯曲实验装置, 对冰煤的试样制备、试验装置、 KIC计算公式以及裂纹尖端塑性区的大小等断裂力学问题进行探讨, 并且对试样尺寸的有效性进行了验证. 结果表明, 断裂韧度KIC与裂纹深度a/W的变化方向相反, a/W越大, KIC越小, 此时裂纹越易开裂.

关键词: 冰煤, 断裂韧度, 裂纹深度

Abstract: Coal is always frozen into block with water in transportation for the purpose of being fixed up and not burned. As a sort of multiple components and a granule aggregation in dispersed state, frozen coal behaves similar to frozen soil. On the basis of its unique ice-cementation effect and the existent of non-frozen water that varies with dynamical balance state between the frameworks of mineral granule, the mechanical behaviour of frozen coal is more complex than usual incompact medium, dependent on load, vibration period and temperature. In order to make it easy to unpack frozen coal, people prefabricate some cracks on it before transportation. In this thesis, experimental study of fracture toughness of frozen coal at low temperature is presented. Three-point bending tests are conducted on frozen coal so as to determine its fracture toughness KIC under various crack length. Sample dimension must meet three essential conditions: plane strain condition, linear elasticity condition and ligament size condition. After the tests, KIC was calculated from the test data, which should be taken take into account with the three essential conditions to validate the validity of the test. The test results show that the value of KIC of frozen coal decreases with shortening the crack length. Thus the crack should be prefabricated deep customarily. But due to vibration action from the carriage, the crack may be getting deeper. So under vibration action, the depth of crack should be prefabricated equal to the reality. Sample preparing, test equipment construction, calculation formula of KIC, of plastic area in crack peak, phenomena of inactivation and development of crack are also discussed.

Key words: frozen coal, fracture toughness, crack lengty

中图分类号: 

  • P642.1