圆形太阳翼模态仿真与试验研究

利用有限元软件SAMCEF实现了圆形太阳翼模态仿真分析，探究了翼面预紧力、约束方式和悬吊弹簧重力卸载系统对太阳翼模态的影响。结果显示，翼面预紧力对太阳翼模态影响较大；支撑车约束方式微小影响太阳翼第一阶模态；有支撑车相比无支撑车，太阳翼第一阶模态频率差值可达32.89%，因此地面试验不能使用支撑车；含悬吊弹簧重力卸载系统可有效减轻重力作用对模态的影响；此外，当弹簧刚度小于7 N/m时，其对太阳翼模态的影响小于0.59‰。随后，采用工作模态法和双点激振方式，经预试验优化地面试验方案；采用正弦扫频方法进行模态测试，获得了圆形太阳翼的前四阶模态振型和固有频率。最后，通过有限元模型修正，使模态仿真结果误差保持在4.16%以内，符合测试相关标准的要求。

Modal Simulation and Experimental Research on Circular Solar Arrays

The modal simulation analysis of circular solar arrays is implemented by using the finite element software SAMCEF. The influences of the wing preload, constraints and suspension spring gravity unloading system on the modes of the circular solar arrays are studied. The results show that the wing preload affects the mode of the solar arrays greatly; the constraints of the support structure slightly affects the first order mode of the solar arrays; the difference between the first order modal frequencies of the solar arrays with and without support structure can reach 32.89%, so the support structure cannot be applied in the ground test; the suspension spring gravity unloading system can effectively reduce the effect of gravity on the mode; in addition, when the spring stiffness is less than 7 N/m, its effect on the mode of the solar arrays is less than 0.59‰. Subsequently, the operational modal analysis techniques and two point excitation method are employed during the test. The testing program is optimized through the pilot tests. The first four vibration modes and natural frequencies of the circular solar arrays are measured by using the sine sweep technique. Finally, through the finite element model modification technique, the error of the modal simulation results is kept within 4.16%, which meets the requirements of relevant test standards.