Optimized strain energy actuated structures

Abstract

A process for designing spacecraft structural elements ( ) that increases spacecraft structure intrinsic damping to relax stiffness design constraints that are necessary for precision pointing requirements. The process includes specifically designing the spacecraft structural elements ( ) to have a stiffness that is intrinsically not suitable to meet mission pointing performance requirements in order to reduce weight and volume. To overcome this deficiency, the structural elements ( ) are equipped with strain energy control elements ( ) that sense strain in the structural elements ( ) from on-board and external disturbances, and provide actuation of the structural elements ( ) to counteract the sensed strain. The strain energy control elements ( ) can be any suitable control element that senses strain and actuates the structural element ( ), such as piezoelectric electric or electrostrictive control elements. By reducing the stiffness requirements of the structural elements ( ), the control elements ( ) can more readily provide a desired actuation for damping purposes in order to meet pointing performance requirements, and thus the weight and volume of the structural elements ( ) can be reduced over those known in the art. Relaxing the stiffness requirements of the structural elements ( ) allows the structural element ( ) to be made of materials having higher strength properties, instead of higher stiffness properties, thus allowing the structural element ( ) to meet the strength requirements to survive launch and deployment loads.