Data for the paper: Mesostructural modification of selected metamaterials manufactured via Laser Powder Bed Fusion from Ti-6Al-4V alloy to improve mechanical properties

This study investigates the mesostructural modification of two metamaterial architectures---Kelvin Cell and Octet Truss---fabricated using LPBF of Ti-6Al-4V titanium alloy. The modifications involved rounding at the unit cell nodes to enhance the metamaterials' effective strength without substantially altering relative density. The paper presents the results of non-linear finite element analysis performed on representative volume elements of the modified structures subjected to uniaxial tensile loading. The simulations utilised material properties of Ti-6Al-4V, typical in manufacturing biomedical implants via LPBF. Each geometry was parametrised across three fillet radii and four relative density levels. The numerical results demonstrated a strong dependence of effective mechanical properties---strength, elastic modulus, and critical strain---on the geometry of the nodal junctions. For the Kelvin Cell structure, these properties improved consistently with increasing fillet radius across the studied range, with negligible impact on relative density. In contrast, for the Octet Truss configuration, optimal rounding enhanced mechanical properties; however, excessive modification reduced effective strength and marked an increase in relative density. Emphasis was placed on critical regions of equivalent and normal stress concentrations and the locations of maximum plastic strain in mesostructures. Two distinct failure mechanisms were analysed concerning the stress and strain distributions.

本研究针对采用激光粉末床熔融（LPBF）工艺制备Ti-6Al-4V钛合金的两种超材料（metamaterial）构型——开尔文胞元（Kelvin Cell）与八面体桁架胞元（Octet Truss）的细观结构改性展开探究。本次改性通过对单胞节点处进行圆角处理，在基本不改变相对密度的前提下提升超材料的有效强度。本文报告了针对改性后结构的代表性体积单元（representative volume element）开展单轴拉伸载荷下非线性有限元分析（non-linear finite element analysis）的结果。模拟过程采用了通过LPBF制备生物医用植入物时常用的Ti-6Al-4V材料性能参数。每种几何构型均设置三种圆角半径与四种相对密度水平进行参数化研究。数值结果表明，有效力学性能——包括强度、弹性模量与临界应变——强烈依赖于节点连接处的几何特征。对于开尔文胞元结构，在本次研究的参数范围内，其力学性能随圆角半径增大持续提升，且对相对密度的影响可忽略不计。与之相反，对于八面体桁架胞元构型，适度圆角可优化其力学性能，但过度改性会降低有效强度，并显著提升相对密度。研究重点聚焦于细观结构中等效与法向应力集中的关键区域，以及最大塑性应变出现的位置。本文针对应力与应变分布分析了两种截然不同的失效机制。