Vibration Damping of Coiled Structures Through Frictional Slip

Citation

Wen, Alexander Huai-Cheng (2024) Vibration Damping of Coiled Structures Through Frictional Slip. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/gvps-8x65. https://resolver.caltech.edu/CaltechTHESIS:12132023-225911259

Abstract

Vibration management is important for the survivability of structures. The response of a structure under vibration is dependent upon interaction between the excitation environment and the properties of the structure. If the input excitation cannot be adjusted, then the structure must be engineered to survive. One approach to engineering structures to reduce vibration response is through damping, which is achieved by adding damping devices or materials to covert kinetic energy into heat, where removing energy from the system reduces the amplitude of response. There are a variety of existing vibration damping concepts and techniques, however, conventional methods of these approaches are subject to limitations such as compromising stiffness for increased damping and performance that is excitation profile dependent.

This research proposes a novel, passive vibration damping concept which is motivated by recent deployable structures for space that use coiling as a packaging architecture. The proposed concept, referred to as "wound roll damping", is a friction-based damping scheme for coiled structures, where the structure is wound around a mandrel with tension that allows interlayer slip during vibration. The friction between slipping layers provides an energy dissipation mechanism, which reduces the overall level of response. The concept was developed with the challenges of mitigating spacecraft launch vibration and the limitations of conventional damping techniques in mind.

Understanding of the working principle and performance of this damping concept is achieved using a combination of experiments, analysis, and FEA. A method for determining the locations of slip within a wound roll under vibration is presented. This consists of modeling the interlayer friction forces, using analytical expressions for the stress fields that arise during tension winding of wound rolls, and comparing these values against loading estimates obtained from analysis and FEA. The locations of slip for wound rolls supported by a cantilevered mandrel with bending vibration modes are towards the root of the wound roll structure, near the inner layers.

Experimental studies that demonstrate the performance and properties of this damping concept are presented in this work. A wound roll test sample is subjected to a range of excitation profiles including: sine sweep, sine dwell, random, and shock with varying levels of sample winding tension and excitation amplitude. Using these experiments, this concept is demonstrated to not be subject to the limitations of conventional damping schemes. This scheme is observed to be capable of significantly increasing the overall stiffness while providing elevated damping levels, with a performance that is tunable with winding tension, independent of excitation profile, and scales with excitation amplitude. The locations of slip are observed to be consistent with predictions from FEA and analysis.

Two approaches to simulate and model the wound roll damper are developed to both better understand the physical mechanism of this concept and provide analysis tools. The first method is an FEA model, consisting of the base vibration of concentric shells and solids that have frictional contact interactions. The second method is a 2-DoF reduced order model that simulates the frictional contact between two mass-spring-damper systems. Both methods are demonstrated to have good correlation with experimental measurements.

A majority of this work demonstrates the performance of this concept, using both experiments and simulation at lab scales. This work also presents simulation studies that demonstrate the viability of this concept at realistic scales. Using simulations scaled to recent coilable space structures, both implemented and proposed, the wound roll damping concept is demonstrated to provide significant stiffness and damping.

Thesis Files