挂索机构几何形状对火箭网系回收动力学的影响

A two-dimensional signed distance field (SDF)-based contact detection method for flexible cables and axially stretched rigid bodies is proposed, for frictional contact dynamics analysis between cable-suspended mechanism and arresting cable in rocket recovery cable system. It can be used to analyze the effect of geometric shape of cable-suspended mechanism on recovery dynamics. Benefiting from the geometric characteristics of axially stretched rigid bodies, the contact detection problem between flexible cables and rigid bodies with complex geometries is transformed into a two-dimensional problem. By utilizing SDF to precisely characterize cross-sectional shapes, combined with offline generation of high-precision SDF and normal fields, and an online bicubic interpolation-based contact parameter calculation method, accurate and efficient frictional contact dynamics computation is achieved. The proposed method is validated through contact dynamics simulations and experiment of a cable and a rigid cylinder. Regarding the arresting cable's hook-entry process during rocket capture, a multibody dynamics model is established and simulations for different cross-sectional shapes are conducted. Results show that the cross-sectional geometries of the cable-suspended mechanism significantly influence localized frictional contact details between the mechanism and the arresting cable, particularly at the cable contact initiation instant, where large-radius filleted cross-sections effectively mitigate impact dynamics compared to sharp-edged configurations.