Transverse curvature characterization of rectangular bistable CFRP laminates with a satellite capturing continuum robotic application

The geometry of a bistable unsymmetric cross-ply carbon fiber reinforced polymer (CFRP) laminate impacts the observed stable configuration curvature. Continuum robotic systems can leverage the multi-stable nature of bistable CFRPs to contort to resemble continuous-bodied appendages observed in nature. The compliance of continuum robots facilitates grasping and manipulating objects such as non-cooperative, tumbling targets encountered in an on-orbit servicing operation. This work investigates large-scale bistable CFRP rectangular laminates previously unexplored in the literature to demonstrate the feasibility of scaling the laminates to meet the needs of potential applications. A numerical parametric study explored the relationship between aspect ratio, thickness, and stable configuration curvature. Non-dimensional parameters enabled the creation of a bifurcation diagram to characterize the stable shapes and bistability. Polynomial regression and machine learning delivered curvature prediction tools. Experiments using an air-bearing zero gravity spacecraft simulator evaluated the feasibility of incorporating rectangular bistable CFRP laminates in an on-orbit servicing continuum robotic system. The initial system resembled a crab claw to grasp target boxes, and the orientation and size of the target significantly contributed to the capture success rate. Future investigations of bistable CFRPs, especially from an application perspective, can benefit from predictive tools like ML to quantify the bistable characteristics.