多材料積層製造於三重週期最小曲面結構之不同邵氏硬度、漸變邵氏硬度與互穿相設計在壓縮機械性質上之研究

Abstract

自然界不斷啟發我們探索並開發仿生材料設計，以滿足工程應用的需求。許多天然結構展現出卓越的特性。三重週期最小曲面（Triply Periodic Minimal Surfaces, TPMS）是一種在蝴蝶翅膀中發現的天然結構，具有相互連通的多孔架構以及可透過數學精確控制的幾何特徵。TPMS結構在設計多孔材料時，能同時達成輕量化與擁有優異機械性能。 在本研究中，多材料TPMS結構被成功設計並製造，並透過壓縮實驗與顆粒模擬法進行研究。系統性地探討了結構的機械性質，包括應力–應變行為、致密化應變、楊氏模數、比能量吸收（SEA）以及應力分佈，並將實驗結果與現有文獻進行比較。本研究探討了三種設計：TPMS-片層（TPMS-Sheet）、TPMS-漸變（TPMS-Graded）以及TPMS-互穿相複合材料（TPMS-IPC）。在TPMS-片層結構中，Gyroid比Primitive在楊氏模數與比能量吸收（SEA）方面展現出更優異的機械性質。使用邵氏硬度範圍為 30 至 95 的材料時，材料硬度的提升會導致更高的應力反應，並影響所有相關的機械性質。實驗與模擬結果一致顯示，層狀塌陷通常從結構的頂部或底部開始，且模擬預測的機械性值普遍高於實驗結果。在TPMS-漸變設計中，其機械行為與漸變相對密度的設計相似，兩種設計在力學表現上有相似特性。Gyroid-Graded與Diamond-Graded結構具有相近的楊氏模數，分別為34.1MPa和34.6MPa，而Primitive-Graded則表現最弱。塌陷現象一律從最柔軟的上層結構開始。對於 TPMS-IPC 結構，其應力–應變曲線通常表現為短暫的彈性區，隨後進入延伸的平臺區。模擬的應力分佈符合實驗中強化材的裂紋生長位置，型變分佈也符合實驗結果，Primitive-IPC從頂部和底部開始、Gyroid-IPC和Diamond-IPC從底部開始發生型變。 這些研究結果能夠優化 TPMS 的設計，尤其在漸變與多材料的應用中提升機械性能，以應用於多種工程領域。

Natural materials constantly inspire us to explore and exploit the materials design space for engineering applications. Numerous extraordinary properties are found in natural materials. Triply Periodic Minimal Surfaces (TPMS) are natural structures discovered in butterfly wings, characterized by interconnected porous architectures and mathematically controllable geometric features. The TPMS structures offer a lightweight and great mechanical performance solution for creating porous material. In this study, multi-material TPMS structures were designed, fabricated, and evaluated through both compression experiments and particle-based simulations. The mechanical properties of the structures—including stress–strain behavior, densification point, Young’s modulus, specific energy absorption (SEA), and stress distribution—were systematically investigated and compared with existing literature. Three designs were explored: TPMS-Sheet, TPMS-graded, and interpenetrating phase composites (TPMS-IPC). For TPMS-Sheet structures, the gyroid topology demonstrated superior mechanical performance in terms of Young’s modulus and SEA compared to primitive, particularly using materials with Shore hardness values ranging from 30 to 95. Increasing material hardness resulted in higher stress responses and influenced all related mechanical parameters. Both experimental and simulation results consistently showed that layer collapse typically initiates from the top or bottom of the structure, with simulations generally predicting higher mechanical property values. In TPMS-graded designs, mechanical behavior was found to be comparable to that based on graded relative density, supporting their alignment in structural performance. Gyroid- and Diamond-Graded structures displayed similar Young’s modulus values, which are 34.1 and 34.6 MPa, whereas Primitive-Graded was the weakest. Collapse consistently began in the softest (top) layer. For TPMS-IPC structures, stress–strain curves typically featured a short elastic region followed by an extended plateau. The stress distribution in the simulation corresponds to the initial position where cracks appear in the reinforcement in the experiment. The deformation distribution also corresponds to the experiment. The Primitive-IPC starts to deform from the top and bottom of the structure; the Gyroid-IPC and Diamond-IPC start to deform from the bottom of the structure. These findings provide valuable insights into optimizing TPMS-based designs for enhanced mechanical performance in graded and multi-material applications.