Abstract: 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.

Key words: Circular solar arrays, Modal simulation, Modal experiment, Model modification