SMMG Seminar | Dr. Shane Johnson from UM-SJTU Jl

Time: 11:00AM-12:00AM

Date: September 19th, 2024

Venue: E1 Room 134, HKUST(GZ)

Coreless Fiber Winding (CFW) is an innovative manufacturing method that employs continuous fibers to rapidly produce complex lattice structures with high strength-to-weight ratios, making it indispensable for industries requiring lightweight and durable components. However, challenges persist in ensuring layer consistency, which is crucial for maintaining flexural stiffness and the second moment of area in composite beams. To mitigate these issues, Finite Element Modeling (FEM) has been employed to predict and address stiffness reductions caused by non-ideal beam configurations. Through optimized winding sequences, the negative effects of layer inconsistency on stiffness can be minimized, thereby enhancing both the time efficiency and structural performance of CFW-manufactured components. Building on the capabilities of CFW, a case study on a semi-custom arm brace demonstrates its effectiveness in producing lightweight, strong, and breathable orthoses. The continuous fiber-reinforced composite lattice structure, fabricated using CFW, achieved reductions in weight and thickness by 44% and 60%, respectively, while maintaining stiffness comparable to 3D-printed alternatives. Validated through nonlinear FEM and experimental testing, this study underscores the potential of integrating CFW into orthotic device manufacturing, offering patients improved comfort and performance through superior fitting and material efficiency. Further exploration of cost-effective custom manufacturing for arm orthoses utilizes Statistical Shape Modeling (SSM) and Principal Component Analysis (PCA) to develop a semi-custom approach. This method employs 12 molds with adjustable thermoplastic connectors to accommodate the entire adult population, offering a scalable solution. Fully customized solutions are enabled through the application of reconfigurable manufacturing molds. These molds, facilitated by SMART (Surface Mold Actuated Reconfigurable Tooling) systems, adapt to significant variability in product surfaces by combining SSM with optimization techniques. This approach ensures precise shape emulation with reduced complexity. Finally, a 2D-3D nested reconfigurable manufacturing system is introduced to manage high and low variation regions, leveraging SSM across multiple dimensions. This system enhances adaptability to size and shape variations while maintaining manageable complexity, providing a scalable solution for custom manufacturing. By continuously managing the interface between ad-hoc and standard regions, this technology enables the production of large, highly variable components in reduced timeframes. This innovation holds significant potential across industries such as medical orthotics and aerospace, where advanced custom manufacturing is critical.

Dr. Shane Johnson is a Tenured Associate Professor at the University of Michigan and Shanghai Jiao Tong University Joint Institute in Shanghai, China. He has multidisciplinary expertise in areas such as analytical, computational, and experimental mechanics, structural analysis, and materials engineering. He specializes in mechanism and machine optimization, compliant mechanism design, new testing techniques, mechanics of composite materials, and finite element analysis. His work has been recognized through multiple NSFC grants.