Mathey Elizabeth, Heimbrook Amanda, Carpenter R D, Kelly Cambre N, Gall Ken
Department of Mechanical Engineering, University of CO Denver, Denver, CO, USA.
Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA.
Comput Methods Biomech Biomed Engin. 2025 Jul;28(9):1477-1488. doi: 10.1080/10255842.2024.2326929. Epub 2024 Mar 12.
There is a significant need for models that can capture the mechanical behavior of complex porous lattice architectures produced by 3D printing. The free boundary effect is an experimentally observed behavior of lattice architectures including the gyroid triply periodic minimal surface where the number of unit cell repeats has been shown to influence the mechanical performance of the lattice. The purpose of this study is to use finite element modeling to investigate how architecture porosity, unit cell size, and sample size dictate mechanical behavior. Samples with varying porosity and increasing number of unit cells (relative to sample size) were modeled under an axial compressive load to determine the effective modulus. The finite element model captured the free boundary effect and captured experimental trends in the structure's modulus. The findings of this study show that samples with higher porosity are more susceptible to the impact of the free boundary effect and in some samples, the modulus can be 20% smaller in samples with smaller numbers of unit cell repeats within a given sample boundary. The outcomes from this study provide a deeper understanding of the gyroid structure and the implications of design choices including porosity, unit cell size, and overall sample size.
迫切需要能够捕捉3D打印所制造的复杂多孔晶格结构力学行为的模型。自由边界效应是在包括类螺旋面三重周期极小曲面在内的晶格结构中通过实验观察到的一种行为，其中已表明单位晶胞重复次数会影响晶格的力学性能。本研究的目的是使用有限元建模来研究结构孔隙率、单位晶胞尺寸和样本尺寸如何决定力学行为。在轴向压缩载荷下对具有不同孔隙率和增加的单位晶胞数量（相对于样本尺寸）的样本进行建模，以确定有效模量。有限元模型捕捉到了自由边界效应，并捕捉到了结构模量的实验趋势。本研究结果表明，孔隙率较高的样本更容易受到自由边界效应的影响，并且在某些样本中，在给定样本边界内单位晶胞重复次数较少的样本中，模量可能会小20%。本研究结果有助于更深入地理解类螺旋面结构以及包括孔隙率、单位晶胞尺寸和整体样本尺寸在内的设计选择的影响。
