Simultaneous dynamic processing strategies of hybrid wire arc additive-milling subtractive manufacturing based on stability region simulation and stiffeners assistance

Abstract

Abstract Hybrid wire arc additive-milling subtractive manufacturing (HWMM) represents an innovative digital direct manufacturing approach for crafting intricate and low-volume structural components by using the two processes alternately. In order to solve the question that the chatter easily occurs and results in the instability of the milling due to the dynamic deposition of the HWMM, a modelling of HWMM was developed by the finite element modal analysis in this paper. Then, a stability region dynamic lobe diagram was drawn according to the dynamic model of robotic milling system "rigid tool-flexible workpiece", which can predict the optimal parameters. Within this parameter optimization range, milling tests demonstrated an absence of chatter. Furthermore, the prediction results of randomly selected parameters within the stable region are in good agreement with the experimental data. Notably, the milling vibration mean and Ra values for the externally chattered sample were 10.5 times and 4.1 times higher, respectively, than those of the stable milling sample devoid of chatter in the same region. In addressing the challenge of diminishing optimization window width with increasing deposition height, and to enhance stability, the impact of stiffeners on natural frequency was investigated. The study revealed that the T-shaped and J-shaped stiffeners induced the most substantial increase in natural frequency, presenting a promising avenue for expanding the process window. A simultaneous dynamic milling strategy of HWMM is proposed based on the stability region simulation and stiffeners assistance, which can determine quickly, and broaden the milling window, and improve the accuracy and efficiency.