Research On Global Stability Of Skeleton-membrane Radome Structure

Due to the strategic needs of the strong military dream and the national defense needs of the modern warfare,the radome for protecting the radar antenna is increasingly prosperous in China.The skeleton membrane structure radome has a huge development potential as an emerging structural form.At present,design methods of this radome has not been fully grasped in China.Only the skeleton is considered in the analysis for bearing load.There is a problem of conservative design.The electromagnetic design is generally emphasized and the structural design is neglected,which should be improved.Based on the above background,the skeleton-membrane structure radome with a diameter of 5.9 meters and 3/4 interception is taken as the research object in this paper.The static loading test research was carried out,and a refined finite element model considering the skin effect was established to simulate the structural behavior accurately.The mechanism of the diaphragm effect was explored.The specific content of the paper includes the following aspects:(1)The static loading test of the structure was carried out.A self-designed multi-stage distribution beam loading system was applied.Therefore,simultaneous multi-stage loading was realized on multi-point of the structure.Three load casescompletely covering skins,partially covering skins and framework-were considered respectively.The force characteristics and structural performance of the structural system were fully understood.The test results show that due to the lateral bracing of the stressed skin on the aluminum alloy members,the prematurely elastic instability of the members around the weak axis is avoided.The global stability bearing capacity of the structure is significantly improved.When a small amount of stressed skin is destroyed,the global stability bearing capacity is still much higher than that for framework case.The phenomenon that the skeleton and the membrane structure work together was revealed.The test provides a test model for numerical simulation and provides the basis for the design of the radome in the same field.(2)A numerical simulation method considering the diaphragm effect was proposed.Based on the finite element analysis software ANSYS,the refined finite element model of the skeleton-membrane structure radome was established.The unit meshing and reasonable parameters were discussed.Finally,the numerical simulation and experimental results were compared to confirm the reliability of the simulation method.(3)The mechanism analysis of the diaphragm effect was carried out.A simplified mechanical model of the diaphragm effect of membranes was proposed.The effects of different structural forms and different load types on the structural stability bearing capacity were analyzed.The typical five-triangular dome structure and double-triangular element structure of the radome were selected for the whole process stability analysis.The instability difference and effect of membranes were summarized,and the influencing factors related to geometric parameters were discussed.The skin effect increases the stability of the bearing capacity between 1.2 and 3.6.The effects of wind load and live load on the overall stability were analyzed.The differences in the structural performance of the diaphragm effect under different load types were compared.