Abstract Structural Battery Composites (SBC) are a new class of multifunctional materials that simultaneously provide structural load-bearing capabilities as well as electrochemical energy storage. By combining these functionalities, the weight and volume of energy storage systems can be reduced. In this work, a multiphysics, multi-objective topology optimization framework is used to design the Structural Battery Electrolyte (SBE) of the SBC. The objectives considered are the minimization of compliance and maximization of effective ionic conductivity. The multi-objective formulation is implemented using the Normalized-Normal Constraint method. This framework uses the finite element method to evaluate the structural and thermal responses and ResNet, a reduced order model, to find the effective ionic conductivity. The sensitivities of all physics are determined analytically using the adjoint sensitivity method. Previous studies have implemented topology optimization for designing SBE; however, these methodologies do not guarantee a bi-continuous design. Bi-continuous domains of the SBE are necessary for efficient ion transport. In this study, a virtual temperature constraint is used in conjunction with the topology optimization framework to prevent electrolyte islands from forming in the design domain. By doing so, bi-continuous behavior of the SBE microstructure can be enforced. Several numerical studies are conducted to demonstrate the capabilities of this framework.
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Virtual element method (VEM)-based topology optimization: an integrated framework
We present a virtual element method (VEM)-based topology optimization framework using polyhedral elements, which allows for convenient handling of non-Cartesian design domains in three dimensions. We take full advantage of the VEM properties by creating a unified approach in which the VEM is employed in both the structural and the optimization phases. In the structural problem, the VEM is adopted to solve the three-dimensional elasticity equation. Compared to the finite element method, the VEM does not require numerical integration (when linear elements are used) and is less sensitive to degenerated elements (e.g., ones with skinny faces or small edges). In the optimization problem, we introduce a continuous approximation of material densities using the VEM basis functions. When compared to the standard element-wise constant approximation, the continuous approximation enriches the geometrical representation of structural topologies. Through two numerical examples with exact solutions, we verify the convergence and accuracy of both the VEM approximations of the displacement and material density fields. We also present several design examples involving non-Cartesian domains, demonstrating the main features of the proposed VEM-based topology optimization framework. The source code for a MATLAB implementation of the proposed work, named PolyTop3D, is available in the (electronic) Supplementary Material accompanying this publication.
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- Award ID(s):
- 1663244
- PAR ID:
- 10170741
- Date Published:
- Journal Name:
- Structural and Multidisciplinary Optimization
- ISSN:
- 1615-147X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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