铝合金耳片连接件结构参数对其断裂特性影响的有限元法模拟

Finite Element Simulation of the Effect of Structure Parameters of Aluminium Alloy Lug Attachment on Its Fracture Characteristic

建立了7000系列铝合金含孔边穿透裂纹斜耳片连接件的三维有限元模型,模拟研究了单边裂纹与双边裂纹两种损伤模式下耳片外内径比值、斜切角、裂纹长度等结构参数对裂纹尖端I型应力强度因子KI值的影响规律。结果表明:在相同等效裂纹无量纲长度下,单边裂纹与双边裂纹两种损伤模式的裂尖KI值随裂纹扩展或斜切角增加的变化规律基本一致;外内径比值大于2的耳片有利于进行损伤容限设计及检查;在相同的裂纹长度下,斜切角15°至25°左右的耳片裂纹扩展速率比直耳片的有明显下降。

The 3-D finite element model for 7000 series aluminium alloy lug attachment with through cracks was established to study the effects of the lug＇s structure parameters such as ratio of outer radius to inside radius, bevel angle and crack length under two types of damage model of single-edge crack and double-edge crack, on I-type stress intensity factor K1 by simulation. The results show that in the same equivalent crack dimensionless length the effects of crack growth and bevel angle on K1 in the two types of damage model were basically accordant. Lugs with R2/R1 〉2 benefited the damage tolerance design and examination. For the lug with 15°-25° bevel angles, the value K1 was obviously less than the straight lug＇s at the same crack length.