Study on the influence of tool rake angle on stress wave effect in high-speed cutting

Stress waves generated during high-speed machining play a decisive role in chip formation, cutting forces, and surface integrity, yet their behavior remains poorly understood. This study clarifies how tool rake angle governs the genesis and propagation of those waves. A photoelastic imaging system captured the produced transient stress patterns while milling a transparent workpiece with tools of negative, zero, and positive rake. Complementary time-resolved numerical simulations reconstructed the evolving elastic field under identical kinematic conditions. The two approaches yield consistent conclusions: the rake angle reshapes the spatial envelope and alters the relative strength of compressive, tensile, and shear pulses. A negative rake concentrates compressive–shear activity near the cutting edge, supporting a stable primary shear zone; a neutral rake produces the most intricate superposition of wave modes, giving rise to fluctuating loads; and a positive rake channels energy preferentially along the feed direction while amplifying tensile release immediately below the rake face. These qualitative trends demonstrate that rake angle acts as an effective design lever for steering stress-wave directionality and damping characteristics without recourse to complex tool coatings or materials. By establishing a direct link between macro-scale geometry and micro-second elastic phenomena, this work provides an experimental–computational foundation for stress-wave-informed optimization of cutting tools, aiming to improve chip control, vibration suppression, and surface quality.