从微孔洞起始的热冲击裂纹的数值研究——Ⅱ:能量释放率分析

贺鹏飞; 李京剑; Yuan C; Stern R; Clegg W J

从微孔洞起始的热冲击裂纹的数值研究——Ⅱ:能量释放率分析

1.
上海交通大学金属基复合材料国家重点实验室,上海200030;同济大学固体力学教育部重点实验室,上海200092;
2.
深圳市宝发实业有限公司, 深圳 ;
3.
Department of Materials Science and Metallurgy, University of Cambridge Pembroke Street, Cambridge CB2 3QZ, UK

基金项目: 国家自然科学基金项目(19972048)和教育部回国人员基金资助项目

详细信息

作者简介:
贺鹏飞(1962),男,博士,教授,博士生导师,主要从事复合材料力学等方面的研究。

中图分类号: TB301
计量
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- 被引次数: 0
出版历程
- 收稿日期: 2001-03-02
- 修回日期: 2001-05-25
- 刊出日期: 2002-10-15

INITIATION OF CRACK FROM THE PORES IN POROUS CERAMICSUNDER THERMAL SHOCK ——Ⅱ:ENERGY RELEASE RATE

1.
Key Laboratory of MMC of China, Shanghai Jiaotong University, Shanghai 200030, China;
2.
Key Laboratory of Solid Mechanics of Ministry of Education, Tongji University, Shanghai 200092, China;
3.
Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ,UK

摘要

摘要: 利用商业的有限元软件ABAQUS,分析了具有微孔洞结构氧化铝陶瓷材料在受到热冲击作用下,从处于材料表面上的开口微孔洞以及临近材料表面的闭口微孔洞的底部起始的裂纹扩展。结果表明:对于从开口微孔洞和闭口微孔洞底部起始的裂纹,其能量释放率随冷却时间的变化规律类似,即随冷却时间t由零开始增加,能量释放率也由零开始快速增大,在冷却时间大约为t=0.1 s时,达到其最大值,随后开始降低。另外对于从开口微孔洞底部起始的裂纹,结果发现裂纹的能量释放率随裂纹长度的增加、微孔洞半径的增加而增加,而对于从闭口微孔洞底部起始的裂纹,其能量释放率随裂纹长度的增加、微孔洞半径的增加、以及微孔洞与材料受热冲击面距离的增加而增加。以开口微孔洞底部起始的裂纹为例,研究了裂纹与临近微孔洞之间的作用,发现临近微孔洞的存在可以明显减小裂纹的能量释放率。这些结果对于从材料的微结构角度设计材料的抗热冲击性能有参考价值。
- 裂纹 /
- 热冲击 /
- 能量释放率 /
- 微孔洞
Abstract: Thermal shock cracks can be initiated at the surface of ceramics materials when the surface was loaded by suddenly cooling. In the present paper, with the commercial finite element method (FEM) package ABAQUS, the initiation of crack for porous ceramics under suddenly cooling was investigated. Two cases, cracks initiating from the pores on the surface and the pores in the neighborhood of the surface of the porous ceramics were studied. For the case of crack initiating from the pores on the surface, it is found that the energy release rate will increase with increasing of the depth of the crack and the radius of the pores. For the case of crack initiating from the pores near the surface, the energy release rate will increase when the crack depth, the pore radius and the distance between the pore and the surface increase.
- cracks /
- thermal shock /
- energy release rate /
- micro-pores