Abstract: In response to the current demand for lightweight spacecraft sunshield,a flexible flat membrane sunshield was designed based on the mass and the effective area ratio on the premise that the effective area of the membrane sunshield remains unchanged.In order to improve the edge stress of the membrane while avoiding the reduction of the effective circle area,the edge of the membrane sunshield was optimized for arc design.The results show that when the thin-membrane sunshield is a regular hexagon,the symmetry of the structure can be ensured,and the minimum mass corresponding to the percentage of unit effective area can be obtained.The stress distribution model of the membrane sunshield was established with the stress superposition method,and the theoretical calculation value of the membrane edge stress was obtained.The influence of the increase of arc edge arch height on the membrane edge stress and the effective circle area ratio was explored.When the two function curves intersect at a point,the optimal arch height of the membrane arc edge can be selected.According to the designed parameters of the thin membrane sunshield,a test prototype of the thin membrane sunshield was built and the tensile experiment was performed.The edge tension of the membrane is high,which proves that the arc edge design plays an important role in improving the stress and stiffness of the membrane.

Key words: membrane, sunshield, stress, arc edge optimization, effective membrane area