|
|
| |
|
|
| 本文已被：浏览 219次 下载 482次 |
码上扫一扫！ |
|
|
| 气孔对铝合金焊接接头超长疲劳寿命的影响 |
|
何超, 崔仕明, 刘永杰, 王清远
|
|
四川大学能源工程安全与灾害力学教育部重点实验室, 成都 610065
|
|
| 摘要: |
| 采用超声疲劳试验方法对铝合金5052-H32焊接接头进行疲劳试验,研究其在超长寿命区间(107~109周次)的疲劳强度及失效机理.结果表明,相同疲劳寿命下焊接接头疲劳强度较母材下降了73.3%,在超高周疲劳区间仍然会发生疲劳破坏;断口观察发现焊接缺陷(气孔)是诱发疲劳裂纹萌生的主要原因.为揭示焊接缺陷对焊接接头疲劳裂纹萌生及扩展的影响,采用有限元技术分析了气孔对应力集中系数和裂纹尖端应力强度因子的影响.最后讨论了焊接缺陷对疲劳寿命的影响机制及裂纹扩展特性. |
| 关键词: 焊接接头 铝合金 超高周疲劳 气孔 应力强度因子 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目(10772125;10372064) |
|
| Effect of pore on super long fatigue life of aluminium alloywelded joint |
|
HE Chao, CUI Shiming, LIU Yongjie, WANG Qingyuan
|
|
Key Laboratory of Energy Engineering Safety and Disaster Mechanics, Ministry of Education, Sichuan University, Chengdu 610065, China
|
| Abstract: |
| In order to investigate the fatigue behavior and failure mechanism in super long life regime, ultrasonic fatigue tests were performed on 5052 aluminium alloy welded joint. The results show that the fatigue strength of welded joint descended about 73.3% as compared to the base metal with the same fatigue life. Fatigue failure occurred in the very high cycle fatigue regime. Fatigue crack initiated from the welding defects(pores) from the observation of SEM. To clarify the effect of pores on thecrack initiation and propagation of welded joint, finite element method was used to calculate the stress concentration and stress intensity factor around the pores. Finally, the characteristics of fatigue crack initiation and propagation with welding defects were discussed. |
| Key words: welded joint aluminium alloy super high cycle fatigue pore stress intensity factor |
|
