Abstract: Researches on the dynamic and control for the flexible spacecraft usually use the modal of the flexible appendages.In order to achieve precision attitude of the spacecraft,the vibration of the flexible appendages need to be suppressed.This problem can be solved effectively with piezoelectric sensor/actuator.The finite element modeling of the solar array with piezoelectric sensor/actuator was presented.The mathematical model was based on the first order shear deformation (FSDT).The dynamic models included the mechanical-electrical coupling effect and axial load in the 3-D beam elements.The shear locking problem was solved by assuming a shear strain field.The results of the modal analysis show that the dynamic characteristics changes with the different distribution of piezoelectric sensor/actuator.The axial load in the tripod of the solar array can increase the swaying frequency largely.The piezoelectric actuators applied voltages can enhance the structural damp of the solar array.

Key words: Solar array, Shear locking, Piezoelectric actuators, Modal analysis, Finite element