Session: 03-04-02: Emerging Materials Technology

Paper Number: 137752

137752 - Reinforced I-Beam Lattices With Enhanced Strength and Energy Absorption 

Beam lattices are a subset of architected materials where the structure is comprised of a network of beam-like struts or rods arranged in a specific geometry or pattern. By optimizing this lattice topology, superior mechanical properties that cannot be found in nature can be achieved, such as high stiffness/strength-weight ratio and excellent energy absorption. However, current beam lattices tend to prioritize either high stiffness and strength (e.g., stretching-dominated) or enhanced energy absorption (e.g., bending-dominated), finding it difficult to excel in both domains simultaneously. For bending-dominated beam lattices, previous studies have shown the potential of using tapered or hollow beams to improve the mechanical properties of the lattices. As one of the most widely used beam structures, I-beam structures have been widely used in various engineering fields and demonstrated great bending resistance and improved failure strength. Therefore, the mechanical properties of beam lattices are likely to be enhanced by replacing the beams in circular cross-sections to I-beams.

This work presents a new class of body-centered cubic (BCC) beam lattices with enhanced stiffness, strength, and energy absorption. The lattices are made of I-shape beams with reinforcements. The previous study from the authors showed much-improved stiffness and strength when using I-beam BCC lattices. Based on this study, joint failure was identified as the major failure mode. Hence, the joint reinforcements in the I-beam BCC lattices will be designed to further improve the energy absorption capability. Multiscale modeling will be performed to investigate the improved stiffness and strength. The unit cell model of the lattices will be created in commercial finite element (FE) code Abaqus and the analysis will be carried out using the Abaqus micromechanics plug-in, where the boundary and loading conditions can be automatically applied. Additionally, three-dimensional (3D) FE simulations will be carried out to investigate the collapse behaviors of the lattices. The 3D FE models will be created using shell elements to reduce the computational costs. We will fabricate the reinforced I-beam lattices using laser metal deposition (LMD) process. To showcase the improved mechanical properties, we will also fabricate the lattices with conventional circular cross-sectional beams. Quasi-static compression tests will be performed to validate the computational models and experimentally demonstrate the enhanced strength and energy absorption of the proposed lattices. Based on the previous study, we expect that the proposed new lattices will enhance at least 100% in stiffness, 50% in yield strength, and 200% in energy absorption, comparing to conventional BCC beam lattices.

Presenting Author: Xin Liu University of Texas at Arlington

Presenting Author Biography: Dr. Xin Liu is an Assistant Professor in the Mechanical and Aerospace (MAE) Department at the University of Texas at Arlington. He is also a member of the Institute for Predictive Performance Methodologies (IPPM) at the UTA Research Institute. Dr. Liu obtained his PhD in 2020 and Master of Engineering in 2016 from Purdue University in Aeronautical and Astronautical Engineering. His expertise is in data-driven multiscale modeling of composite materials and structures. He has authored/co-authored 40+ journal papers and refereed conference papers. He also developed 4 computer codes for multiscale modeling of composites. He received the American Society for Composites (ASC) Ph.D. Research Scholarship Award in 2018 and Purdue University Koerner Scholarship in 2017.