Dynamic Modeling and Analysis of Rigid-Flexible Coupled Unfolding Mechanisms Under Transient Actuation

Transient mechanisms are increasingly applied in fields such as high-speed aircraft, super high-speed trains, and underwater robots. However, in high-speed motion, large inertial forces are inevitably generated, which can easily lead to elastic deformations in some flexible components of high-speed mechanisms, thereby affecting the performance of the mechanical system. To address this issue, this paper focuses on a transient unfolding mechanism driven by a high-speed actuator with flexible leading-edge rods. A rigid-flexible coupling dynamic model of the transient unfolding mechanism is established using the Absolute Nodal Coordinate Formulation (ANCF), and the theoretical model is validated by comparison with simulation models. The impact of flexible rods on the mechanism’s motion characteristics is studied, analyzing the effects of different deployment times, mechanism parameters, and rod materials on the mechanism’s dynamic properties. Based on this, four classical impact signals are chosen as input conditions to analyze the transient response characteristics of the mechanism under different input conditions. The dynamic characteristics of the transient mechanism are explained from an energy transfer perspective. Finally, a prototype of the transient unfolding mechanism is developed, and transient deployment tests are conducted. The test results verify the accuracy of the rigid-flexible coupling model established in this paper. The research findings provide valuable insights and guidance for the study and application of transient mechanisms.