超塑成形/扩散连接焊缝失效断裂仿真方法

Simulation Method for Bonding Seam Failure of Superplastic Forming and Diffusion-Bonded Structures

针对采用超塑成形/扩散连接工艺加工的3层瓦伦空心结构钛合金空心风扇叶片的焊缝强度通常低于材料本体强度且受零部件几何特征影响显著的特点,提出采用带失效的固连连接方式.通过剪切失效和拉伸失效模拟焊缝物理特性的建模和仿真分析方法,以及与空心风扇叶片相同加工工艺、相同结构形式的空心平板试验件的靶板冲击试验,首先建立焊缝失效模型,标定了焊缝强度,然后将数值仿真结果与试验数据相比较,验证该方法的有效性.结果表明,所提出的超塑成形/扩散连接结构仿真分析方法能够为航空发动机3层瓦伦空心结构零部件瞬态动力学分析提供参考.

In view of the fact that weld strength is usually lower than the material strength, and geometric characteristics of parts is affected by the significant features when using the superplastic forming and diffu- sion-bonded process to build the hollow warren thin wall structures, and based on the study of the deform- ation of diffusion bonding components and failure mechanism of bonding seam, this paper proposed a novel method in which thick shell elements were used to model diffusion bonded components. Moreover, the tied contact with failure mode was used to model bonding seam physical properties, and its strength parameters were related to geometric characteristics. The impact tests of hollow warren thin wall structures based on superplastic forming were performed, and numerical simulation results were compared with the test data. The results show that the method proposed in this paper can be used for dynamic analysis of model bonded hollow warren structures.