Session: 12-29-02: Mechanics of Soft Materials

Paper Number: 145051

145051 - Dynamic Response of Soft Artificial Fabric Muscle Actuators for Launch and Recovery Systems 

Automation in undersea and surface vehicles presents challenges for their launch, recovery, positioning and control (LRP&C). Traditional rigid handling and actuator systems are often volume constrained and can limit payloads capacities and operational effectiveness. These systems have excellent potential for use in launch, recovery, positioning, and control of undersea and surface vehicles and interface platforms. The rising demands for rapid deployment and stowage of scalable and adaptable systems intensifies the requirement for high-capacity and compact actuation technologies. On-demand inflatable and compactable soft actuators provide unique solutions with robustness needed to operate in extreme underwater environments. This research investigated soft fabric muscles (ASFMs), also known as McKibben muscles. The ASFMs are constructed of High-Performance Fibers (HPFs) surrounding an inflatable bladder structure.  Inflatable and on-demand deployable/compactable actuator technologies coupled with state-of-the-art HPF materials and soft robotics can provide transformational and disruptive LRP&C solutions with the enhanced robustness necessary for autonomous missions in extreme underwater environments. Inflatable structures provide a fail-safe mechanism in the form of elastic wrinkling where, upon restoration from overloading, inflatable structures fully recover.

Previous work performed by the Naval Undersea Warfare Center Division Newport with ASFMs for LRP&C investigated the linear actuation behaviors of ASFMs, including the actuation length and the force-pressure relationships. The HPFs investigated consisted of both glass and aramid braid materials, incorporated into a range of actuator diameters and lengths. The performance is characterized through both computational mechanics and physical experiments on air inflated ASFMs. The computational models supported the fluid/structure interactions by using an Equation of State (EOS) that governed the thermomechanical behaviors of the internal air during volumetric expansion and axial contraction of the ASFMs. ASFMs operating in deep-water hydrostatic and hydrodynamic environments present new focus areas not previously considered for artificial soft muscles.  This previous and current research combines multiple disciplines in the areas of inflatable structures, soft robotics, hydraulics and pneumatics, HPFs, thermodynamics and nonlinear materials.

This research studies the performance of ASFMs in order to advance the technology base for next-generation soft actuators used in LRP&C operations. Experimental tests were performed on circular braided ASFMs constructed of different high performance fiber materials, such as fiberglass and aramid, having a range of 2.0-inch to 10.0-inch nominal diameter.  A Finite Element Analysis (FEA) model is created to capture the performance of the ASFMs. A correlation study evaluates the performance of the FEA model with respect to analytical and test results. These results uniquely identify the behavior of ASFMs for use in LPR&C operations.

Presenting Author: Michael Smith Naval Undersea Warfare Center Division Newport

Presenting Author Biography: Mechanical Engineer with B.S. in Mechanical Engineering from Rensselaer Polytechnic Institute (2017) and M.S in Mechanical Engineering from University of Rhode Island (2019). Michael began working for the NUWCDIVNPT Mechanics of Advanced Structures and Materials team following his graduation in 2019. His research focuses on the characterization and design of novel materials and structures, including but not limited to: high-performance fabrics, inflatable structures, composite materials, biomimetic materials, cold spray coatings, and thermal insulation materials.

Authors:

Michael Smith Naval Undersea Warfare Center Division Newport
Kaelyn Gamel Naval Undersea Warfare Center Division Newport
Allison Redington Naval Undersea Warfare Center Division Newport
Eric Warner Naval Undersea Warfare Center Division Newport
Paul Cavallaro Naval Undersea Warfare Center Division Newport