Session: 03-08-01: Computational Modeling and Simulation for Advanced Manufacturing

Paper Number: 110952

110952 - Structural Simulation, Structural Optimization, and Winding Sequence Optimization Strategies for the Design and Fabrication of Coreless Filament Wound Composite Lattices 

Coreless Filament Winding (CFW) has great potential in the fabrication of composite lattice structures due to its extremely high fabrication speed. In addition, the fiber orientation can be locally controlled since the fiber is wound around some pins instead of a mandrel during CFW. Therefore, it can fabricate structures with complex geometries and high structural efficiency.

Winding with continuous fiber roving is preferable which guarantees the load-bearing capacity and the fabrication speed without cutting and restarting during the winding process. Since the fiber is wound around pins whose diameter cannot be infinitesimally small, each structural element may have four possible beam configurations, which depend on the in-plane local coordinates of the start and/or end of the beam. In this case, layer inconsistency, a condition that a structural element with multiple layers has different beam configurations, may inevitably occur in the fabricated structure. It will decrease the second moment of area of the structural element and may lead to reduced flexural stiffness of the structure. However, the effect of layer inconsistency on the structural performance, which depends on the practical winding sequence, is generally lacking in the literature.

In this study, a detailed Finite Element Model (FEM) which characterizes the practical beam configurations was developed to explore the influence of layer inconsistency on the flexural stiffness of the structure. To improve the structural-efficiency and the fabrication time-efficiency, a structural optimization and a winding sequence optimization were developed for the design and fabrication of CFW structures. The structural optimization minimizes the total fiber-length and considers the feasibility to wind with continuous roving. After obtaining the optimized material distribution, the sequence optimization was implemented to design the winding sequence by minimizing the stiffness reduction effect due to layer inconsistency. Lattice structures were fabricated by using a manual CFW process based on the obtained winding sequences and applied to a compression test. The force versus displacement relationship were compared to the result of the detailed FEM.

The result shows that the detailed FEM provides a reliable prediction of the structural stiffness (average error≤5.4%). Different winding sequences provide different levels of layer inconsistency, resulting in different stiffness reduction percentages. Although the layer inconsistency may inevitably reduce the structural stiffness, the developed sequence optimization decreases the stiffness reduction due to layer inconsistency from 51.3% to 13.7%. In short,  the developed structural and sequence design strategies provide instructions for the CFW process, which improve the fabrication time-efficiency and the structural-efficiency. This promotes the application of CFW in the high-speed fabrication in various engineering applications, e.g., aerospace, automobile, and architecture structures, which require high structural performance.

Presenting Author: Yaru Mo UM-SJTU Joint Institute, Shanghai Jiao Tong University

Presenting Author Biography: Yaru Mo is a PhD student from UM-SJTU Joint Institute, Shanghai Jiao Tong University who is doing research in composite lattice, design and fabrication of rehabilitation devices.

Authors:

Yaru Mo UM-SJTU Joint Institute, Shanghai Jiao Tong University
Siwei Ye UM-SJTU Joint Institute, Shanghai Jiao Tong University
Shane Johnson UM-SJTU Joint Institute, Shanghai Jiao Tong University