利用仿生設計具高性能之創新結構材料

Design Structural Materials with Superior Mechanical Performance by Bio-inspiration

林湘迪(Xiang-Di Lin)

指導教授 ： 張書瑋

國立臺灣大學/工學院/土木工程學研究所/碩士(2019年)

https://doi.org/10.6342/NTU201902474

摘要

近年來，生物結構成為材料設計的靈感來源，透過模仿生物建構結構的方式及特徵，可望設計出高性能之創新結構材料。生物材料通常由硬而脆的礦物質與軟而韌的蛋白質形成複合材料，不同尺度下的強化、韌化機制，使其性能更勝人造材料，故本研究主要探討複合材料之微結構對力學性質的影響。
本研究專注在兼具強度、韌性之結構性生物材料研究，使用二維三角晶格彈簧的顆粒模型，預測複合材料的行為及破壞模式。此模型可以正確計算出材料的機械性質和再現韌性機制，本研究分別對骨骼及楓香進行仿生結構的設計，骨骼中的骨單位為同心圓排列的結構，本研究透過改變仿骨骼結構的設計參數，不僅探討圓形的微結構，還分析軸長比、拓樸間的距離與同時存在著不同大小微結構的影響，找到具高強度與高韌性的仿骨骼結構，並釐清高韌性的破壞機制，藉此提供仿生材料的設計方向。
楓香（Liquidambar formosana）具有楓葉狀葉子和類似毛刺的果實，其結構內有許多孔洞，在壓縮下能支撐整個結構。本研究藉由楓香框架腔室結構的啟發，提出了五個仿楓香果實結構的模型，並且設計出輕量化高韌性仿楓香果實結構的孔洞複合材料，結果顯示韌性可達 6 至 12 倍。

關鍵字

模擬 ； 機械性質 ； 仿生材料 ； 複合材料 ； 骨骼 ； 楓香

並列摘要

In recent years, biological structures have risen as a source of inspiration for the material design. There is great potential in designing high-performance structural materials by mimicking the construction and properties of biological structures. Biomaterials are usually made of composite materials using hard and brittle minerals, along with soft and tough proteins. Due to this composition, the strengthening and toughening mechanisms of biomaterials are superior to artificial materials. Thus, the objective of this study is to discuss the effect of microstructures within composite materials in terms of mechanical properties.
This study focuses on the strength and toughness of structural biological materials. In this study, we present a 2-D lattice spring model to predict the performance of composite materials, and their failure modes. The model is able to precisely estimate the material performance and reproduce the toughening mechanisms. In this study, bone inspired structure and Liquidambar formosana inspired structure were designed separately; the osteon in bone is concentrically arranged. In addition, by changing the design parameters of the bone inspired structure, both the circular microstructure and the ratio of axial and length were analyzed. Furthermore, the influence of the distance between the topography and different sizes of microstructures were analyzed. We have found one particular bone inspired structure which possesses high strength and high toughness. Last but not least, we clarified the toughness and damage mechanism, thereby providing the design direction of the biomimetic material.
Liquidambar formosana has maple-like leaves and burr-like infructescences. The buckyball-like framework inside is composed of large holes (cells), which supports the whole structure under compression. In this study, five models were proposed to test the strength based on the inspiration of cellular structures of Liquidambar formosana. The Fibonacci composite materials were designed and exhibited six to twelve-fold improvement in toughness.

並列關鍵字

Simulation ； Mechanical Property ； Bio-inspired Materials ； Composites Material ； Bone ； Liquidambar formosana

參考文獻

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[5] Zhao, N. (2014). “Bioinspired materials: From low to high dimensional structure, ” Adv. Mater, 26, 6994–7017.