KY Space Grant REU-24-024: Optimal Design and Uncertainty Quantification of Lattice Structures for NASA Landing Systems

ABSTRACT Project Title: Optimal Design and Uncertainty Quantification of Lattice Structures for Lightweight Landing Systems Project Dates: 05/01/2024-01/31/2025 The primary objective of this Research Experience for Undergraduates (REU) project is to advance the design and manufacturing of robust and lightweight lattice structures intended to provide effective protection against impact loads during spacecraft landings. Lattice structures demonstrate considerable promise in enhancing the efficiency of landing systems for space missions due to their distinctive mechanical properties, lightweight characteristics, and adaptability. While NASA has undertaken significant research efforts in developing and testing lightweight lattice structures, there is still a critical knowledge gap regarding the optimization of these structures concerning the microscopic features and the effects of manufacturing imperfections on the behaviors of lattice structures during landing. To tackle these challenges, the central strategy of this project involves the development and validation of a comprehensive computational framework. This framework leverages the Finite Element method, the Limit Analysis method, and the Monte Carlo method to model and analyze the complex behaviors of lattice structures. The specific lattice structure under primary investigation is the stretching-dominated octet-truss lattice. The project unfolds in two key phases. The initial phase centers on the optimal design of lightweight lattice structures with a particular emphasis on superior mechanical performance under various compression loads. The design variables encompass parameters such as the number of unit cells, surface orientations, and aspect ratios. The second phase delves into the quantification of uncertainties arising from geometric and material variations. This includes an examination of factors such as cross-sectional areas of structural components and yield strengths of the base material. The objective is to assess how these uncertainties impact the mechanical performance of the lattice structure, encompassing aspects of stiffness and strength. By addressing these critical issues, it is expected that this project will significantly expedite the design and fabrication processes associated with lightweight lattice structures tailored for future space applications.