Highly Compressible Origami Bellows for Harsh Environments

Highly Compressible Origami Bellows for Harsh Environments Jared J. Butler Department of Mechanical Engineering, BYU Master of Science The use of origami-based bellows is of interest in fields where traditional metal bellows are incapable of meeting compression, mass, or flexibility constraints. Metal bellows are often used in space applications but frequently complicate spacecraft design. Origami-based bellows capable of meeting design constraints while adequately shielding sensitive spacecraft parts may be advantageous to space mechanism design. The design and testing of a highly compressible origami bellows for harsh environments is described. Several origami patterns were evaluated and the Kresling fold pattern was designed to meet constraints and selected for use in the bellows design. Origami bellows were prototyped in five different materials and tested in fatigue, thermal cycling, ablation, and radiation. Tested bellows show good fatigue life exceeding 100,000 cycles for some materials and resilience to potential harsh environmental conditions such as thermal cycling, abrasion, and high radiation. The bellows can be designed to fit within a given inner and outer diameter and stroke length depending on the design requirements. The origami bellows shows promise for space application and as an adequate replacement for current metal bellows due to its high compressibility and low mass. The design, testing, and fabrication of an origami-based bellows for microgravity drilling is presented. The benefits of origami created an opportunity for application on NASA’s Asteroid Redirect Mission (ARM) to protect sensitive parts from debris. Origami-based bellows were designed to fit spacial limitations and meet needed compression ratios. Designs have demonstrated high mass reductions, improved stroke length, greatly decreased stowed volume, improved flexibility, and reduced reaction forces in comparison with traditional metal bellows. Material and design testing demonstrated that a nylon-reinforced polyvinyl fluoride based bellows with an aramid fiber stitched seam is well suited for debris containment in space conditions. Various epoxies were able to maintain an adequate bond with polyvinyl fluoride below expected environmental temperature for bellows mounting to the ARM drill. Asymmetric compression of the bellows can occur at extreme low temperatures and is preventable by balancing stiffness within the structure.