Numerical Studies of the Mechanics of Additively Manufactured Tape Springs for Space Applications

The tape spring may be classified as a thin-walled structure made of polymer, metal, or composite material of carefully designed thickness, length, curvature, and stiffness. It is used in space vehicles to deploy stowed solar panels after reaching orbit. The structure is characterized based on the longitudinal and transverse curvatures after deformations. This is key to the successful stowage of the tape spring at ground level and later its deployment after the space vehicle reaches destined orbit. The present research explored into the M-θ relationship of 3D-printed Onyx tape springs using the finite element analysis (FEA). The bending moment and displacement behaviour of the tape springs were predicted by analyzing important parameters, such as layer thickness and radius of curvature. The experimental M-θ relationship was obtained using the three-point bending tests using a custom-designed and fabricated fixture to capture critical data such as maximum bending moments and deflections. The challenges encountered in the 3D-printing of Onyx tape spring on the Markforged® machine included obtaining uniform thickness, material, and strength distribution throughout the tape spring.