摘要
以不同尺寸孔洞缺陷的2024铝合金搅拌摩擦焊接头为研究对象,在对接头进行分区建模基础之上,通过试验和有限元数值模拟研究了接头孔洞大小对接头服役裂纹扩展的影响规律。研究表明,接头在准静态服役条件下,力学性能随孔洞减小而不断提高;孔洞直径减小至0.1 mm时,接头力学性能与无缺陷接头相同,断裂于热影响区;而当孔洞直径大于0.1 mm时,接头均断裂于含有孔洞缺陷的焊核区。在交变载荷服役条件下,接头疲劳力学性能随孔洞减小而不断提高,随孔洞增大对载荷的敏感性逐渐降低;断裂的瞬间断口会有温升现象且均断裂于有孔洞缺陷的焊核区。
Based on the partition modeling of the FSW joint with holes for 2024 aluminum alloy, the influence of the joint hole size on crack propagation was studied by experiments and finite element simulation. The results show that the mechanical properties of the joint increase with the decrease of the hole size under quasi-static service conditions. When the hole diameter is less than 0.1 mm the mechanical properties of the joint are basically the same as those without the defect and the fracture occurs in the heat affected zone. The weld nugget zone(WNZ) with hole defect fractures when the diameter of the hole is larger than 0.1 mm. The fatigue properties of the joint increase with the decrease of the hole size under the condition of fatigue load, and the sensitivity to the load decreases gradually with the increase of the hole size; there will be a temperature rise in the fracture and the fracture always takes place in the WNZ with the hole defect.
引文
[1] Borrisutthekul R, MiyashitaY et al. Science&Technology of Advanced Materials[J], 2005, 6(2):199
[2] Picketta A K, Pyttel T, PayenF et al. International Journal of Impact Engineering[J], 2004, 30:853
[3] Ma Guodong(马国栋). Thesis for Master(硕士论文)[D].Beijing:Beijing Jiao Tong University, 2016
[4] Chen Zhiying(陈志英). Thesis for Doctorate(博士论文)[D].Shanghai:Shanghai Jiao Tong University, 2009
[5] Unger D J. Journal of Elasticity[J], 2014, 117(2):139
[6] Griffith A A. Philosophical Transactions of the Royal Society A Mathematical Physical&Engineering Sciences[J], 1921,A221:163
[7] Irwin G R. Journal of Applied Mechanics[J], 1957, 24:361
[8] Song Zhanxun(宋占勋),Fang Shaoxuan(方少轩),Xie Jilong(谢基龙). Journal of Mechanical Engineering(机械工程学报)[J],2013(2):87
[9] Fan Junling(樊俊铃),Guo Xinglin(郭杏林). Journal of Mechanical Engineering(机械工程学报)[J],2015(10):33
[10] Raymond S D, Wild P M, Bayley C J. Journal of Materials Processing Technology[J], 2004, 147(1):28
[11] Panda S K, Kumar D R, Kumar H et al. Journal of Materials Processing Technology[J], 2007, 183(2):321
[12] Liu H, Maeda M, Fujii H et al. Journal of Materials Processing Technology[J], 2003,22(1):41
[13] Garware M, Kridli G T, Mallick P K. Journal of Materials Engineering and Performance[J], 2010, 19(8):1161
[14] Jolu T L, Morgeneyer T F, Denquin A et al. International Journal of Fatigue[J], 2015,70:463
[15] Zhong Jifa(钟继发). Thesis for Master(硕士论文)[D].Changsha:Central South University, 2014
[16] Gao Yunzhen(高云震).Fracture Toughness of Aluminum Alloy(铝合金的断裂韧性)[M]. Beijing:Metallurgical Industry Press, 1980