基于随机振动仿真分析的阵列天线结构改进

Structural Improvement of Array Antenna Based on Random Vibration Simulation Analysis

某型阵列天线属于机载设备,在做完随机振动试验后,第2个天线单元的一个辐射板被振裂。为了快速找到断裂原因,改进天线结构,利用有限元仿真软件ANSYS Workbench进行随机振动仿真分析。分析结果表明:原天线单元辐射板根部圆角太小,产生较大应力集中,最大3σ应力为102.74 MPa,超过材料疲劳极限应力87 MPa;改进后的天线结构,最大3σ应力降低24.2%,其数值为77.85 MPa,小于疲劳极限应力,满足设计要求。最终,改进后的天线结构顺利通过振动试验,有效验证了仿真分析与结构改进的合理性。

A array antenna belongs to airborne equipment. A radiation plate of the second antenna element was cracked after random vibration test. In order to find out the fracture cause quickly and improve the antenna structure,the finite element software ANSYS Workbench was used to carry out random vibration simulation analysis. The analysis results show that the root fillet of the original antenna element is too small, resulting in stress concentration.The maximum 3σ stress is 102.74 MPa which is more than the fatigue ultimate stress 87 MPa of aluminum alloy. The maximum 3σ stress of the improved antenna structure is 77.85 MPa, reduced by 24.2%, which is less than the fatigue ultimate stress. So it meets the design requirements. Finally, the improved antenna structure has passed the vibration test smoothly, which effectively verifies the rationality of the simulation analysis and structural improvement.