Study on the stability of space sleeve stretching arm in the transition stage on non-continuous rigid surfaces based on scale optimization of elastic micro-convex bodies

To address the challenges of extension/retraction distance, stiffness, and accuracy in space telescope sleeve-type stretching arms, a wheel-type variable-diameter internal drive device has been employed as a replacement for the existing driving mechanism. However, during the research process, it was discovered that when the elastic body comes into contact with a non-continuous rigid surface, there is a transitional instability phenomenon caused by elastic friction contact and elastic collision. To tackle this issue, the analysis begins by utilizing fractal theory and Hertz contact theory to optimize the scale of micro-convex bodies. This analysis considers the deformation of the substrate and the micro-convex bodies after their interaction with the elastic body surface. Additionally, the model incorporates the effects of elastic rolling friction and collision time, establishing a normal contact stiffness model for the contact surface during the inter-stage transition. Subsequently, finite element analysis and experimental prototypes are employed to verify and analyze the findings. The results indicate that the scale variation and deformation of elastic micro-convex bodies after interaction have a significant influence on the normal contact stiffness of the contact surface. Therefore, optimizing the scale and spatial arrangement of elastic micro-convex bodies can effectively enhance mechanical properties and ensure stability during the transition on non-continuous rigid surfaces.