Design, mechanical properties, and optimization of BCC lattice structures with taper struts. (1st September 2022)

• Record Type: Journal Article
• Authors: Zhao, Miao; Zhang, David Z.; Li, Zhonghua; Zhang, Tao; Zhou, Hailun; Ren, Zhihao
• Is Part Of: Composite structures. Volume 295(2022)
• Publication Date: 2022-09-01
• Subjects: Lattice structure -- Mechanical properties -- Topology optimization -- Additive manufacturing; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2022.115830
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: The fractures of lattice structures are mainly near the nodes during loading due to the stress concentration, resulting in low mechanical properties. In this study, a novel parametric approach was proposed for modelling Body-Centered Cubic (BCC) lattice structures with taper struts to reduce the stress concentration at nodes and improve the mechanical properties. The mechanical properties and deformation behavior of lattice structures with different taper struts were investigated through finite element analysis and uniaxial compression tests. The simulation results demonstrate that tapered struts significantly reduced the anisotropy of BCC lattice structures and increased the elastic modulus by up to 67%, while the shear modulus was only improved for a slight tapering by less than 2.92%. In addition, the fracture occurred due to the combination of high plastic strain and tensile stress, and the fracture site of BCC lattice structures changed from the node region to the center of strut due to the tapering of the strut cross-sections, which corresponded to the experimental results. Finally, an optimization strategy was developed to simultaneously optimize the distribution of volume fraction and strut geometry of BCC lattice structures, demonstrating the effectiveness of the proposed design and optimization method for lightweight applications.