基于刚度的环形天线索网参数匹配设计方法

Parameter Matching Design Method for Ring Truss Antenna Based on Stiffness Requirement

正向测试型面与反向测试型面相加平均是大型柔性天线型面测试中常用的消除重力变形的方法。部分环形天线索网由于构型的原因,使得主副索网在垂向刚度不一致,这可能导致反射面在两种状态下重力变形相差较大,使上述方法失去作用。通过单段绳索端点垂向刚度推导出环形索网天线主副索网对应节点的垂向刚度比值公式,式中主副索网对应节点垂向刚度比值与主副索网材料模量、绳索截面尺寸成正比,与主副索网焦距的平方成反比,且各节点刚度比趋于一致。利用该结论,通过改变索网中主副索网绳索截面参数比值可实现环形天线索网主副网节点垂向刚度相等的设计目的。使用ANSYS软件模型对上述方法进行了验证,结果表明该方法正确可行。

Average the sum of the surface errors of cup-up and cup-down is a usual way to eliminate the effect of reflec-tor gravity when a antenna surface error is evaluated. But it may doesnl work when the stiffness of the front net and the rear net are not equal in gravity direction due to the ring truss antenna^s asymmetrical shape.The article derived the stiffness ratio formulation of the front net cables to the rear net cables from the stiffness property of a cable changing with angle. According to the formulation, the ratio is in direct proportion to the material module or the area of the cross section of cable and is in re-verse proportion to the focus of net.The ratios in the whole networks are almost same.Base on the conclusion,the front net and the rear net of a asymmetrical networks could be designed with equal stiffness by changing the ratio of the cross section areas of the front net cables to the rear net cables＇. Models made by ANSYS were used to verify the validity of the method.The result showed that the method was feasibility.