To reveal the fundamental causes of this precision degradation, this study systematically investigates the vibration mechanisms and energy transfer characteristics of impact rods under thermo-mechanical (multiphysics) coupling. Based on Timoshenko beam theory, a dynamic model of the robotic arm incorporating temperature gradients was established. Constitutive equations and a finite element model under unsteady temperature fields were derived to analyze the influence of thermo-mechanical coupling on vibration behaviors. Additionally, the structural sound intensity method and a novel concept of "contribution degree" were introduced to quantitatively analyze vibration energy transfer and distribution patterns. Simulation results indicate that the robotic arm's first natural frequency is 39.13 Hz, with a dominant lateral bending mode, constituting the core factor affecting end-effector positioning accuracy. Structural sound intensity is primarily dominated by the thermal field, gradually shifting to mechanical excitation dominance as time progresses. The introduction of damping significantly reduces resonance peaks and suppresses high-frequency vibration energy transfer. Under a 1000 N impact excitation, the vibration response exhibits a two-stage characteristic, with vibration energy demonstrating pronounced spatiotemporal attenuation effects during propagation along the arm structure. These findings provide a critical theoretical foundation for subsequent active vibration suppression and precision control strategies.
LI et al. (Tue,) studied this question.