Abstract：
Some typical defects like delamination, fiber fracture, non-uniform resin distribution and springback are inevitable as titanium-based thermoplastic FMLs are formed by general stamping process at elevated temperature due to the significant differences of various constituent materials in mechanical and thermal properties as well as deformation mechanism. Thus, a novel ultrasonic impact sizing/shaping process method was proposed in the present work, in which a stepped horn and impact tools with a cylindrical tip end was designed by means of vibration modal and harmonic response analysis, and the corresponding experiment setup was established to verify the process mentioned above. Moreover, ultrasonic impact tests were carried out for titanium-based FMLs stacked by titanium sheet, thermoplastic resin film and carbon fiber reinforced fabric to reveal their sizing/shaping mechanism and the effect of key process parameters such as ultrasonic amplitude, scanning speed of impact tool and its tip end diameter on the surface and interface characteristics of titanium-based FMLs. The research results show that the ultrasonic impact scheme with the ultrasonic amplitude of 12 μm, the scanning speed of impact tool within 2 mm/s ∼ 3 mm/s, the tip end diameter of impact tool within Ø4mm∼Ø6mm are proper for the ultrasonic impact sizing/shaping process of titanium-based FMLs.
摘要：
一些典型的缺陷，如分层，纤维断裂,不均匀的树脂分布和回弹是不可避免的，因为钛基热塑性塑料FML是通过一般冲压工艺在高温下形成的，由于各种组成材料在机械和热性能以及变形机理上的显着差异。因此，在目前的工作中，提出了一种新颖的超声冲击施胶/成形工艺方法，通过振动模态和谐响应分析，设计了具有圆柱形尖端的阶梯式喇叭和冲击工具，并建立了相应的实验装置来验证上述过程。此外，对钛片堆叠的钛基FMLs进行了超声冲击试验，热塑性树脂膜和碳纤维增强织物，揭示其上浆/成型机理和超声振幅等关键工艺参数的影响，冲击工具的扫描速度及其尖端直径在钛基FML表面和界面上的特征。研究结果表明,超声振幅为12μm的超声冲击方案,冲击工具的扫描速度在2mm/s~3mm/s内，冲击工具的尖端直径在Ø4mm〜Ø6mm范围内适用于钛基FML的超声冲击尺寸/成形过程。
