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| 3D打印珍珠贝壳仿生梁断裂性能研究与理论分析 |
| Fracture Performance and Theoretical Analysis of 3D-Printed Nacre-Inspired Beams |
| 投稿时间：2026-02-03 修订日期：2026-04-14 |
| DOI： |
| 中文关键词: 3D打印混凝土 贝壳珍珠层结构 断裂性能 试验研究 |
| 英文关键词: 3D-printed concrete bio-inspired nacre interface fracture performance experimental study |
| 基金项目:安徽省高校省级自然科学研究重大项目（2024AH040037）；安徽建筑大学科研储备库培育项目（2025XMK07）； |
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| 中文摘要: |
| 3D打印混凝土常面临层间粘结弱与脆性断裂问题。受珍珠母“砖-浆”结构启发,本研究提出一种仿生层合设计,通过刚性3D打印混凝土薄层与柔性聚脲夹层交替排列,以提升打印梁的断裂性能。本文制备了四组梁试件,采用不同打印路径与夹层设计组合(平行与交叉打印、有无聚脲),开展三点弯曲与劈裂抗拉试验,并基于双K断裂准则与断裂功方法分析荷载-裂缝口张开位移响应。为量化聚脲体系的贡献,引入聚脲改性因子,采用内聚力模型将与聚脲层的抗拉强度、延性、厚度及界面断裂能相关联。结果表明，交叉打印可使断裂能提升约18.5 %，而引入聚脲夹层后断裂能进一步翻倍；仿生交叉打印聚脲梁的断裂能达154.4 J/m2，较传统平行打印梁提升约167.7 %，初始抗裂性与失稳断裂韧性增幅达40 %–50 %，劈裂抗拉强度亦显著提高。实验与模型分析表明，“砖-浆”结构与聚脲改性界面的协同作用能通过多尺度能量耗散有效抑制裂纹失稳扩展，为仿生3D打印混凝土梁的断裂性能设计提供了实验依据与机理支撑。 |
| 英文摘要: |
| 3D-printed concrete often suffers from weak interlayer bonding and brittle fracture. Inspired by the "brick-and-mortar" structure of nacre, this study proposes a bio-inspired laminated design in which rigid 3D-printed concrete lamellae are alternated with flexible polyurea interlayers to improve the fracture performance of printed beams. Four groups of beams were fabricated with different combinations of printing path and interlayer design (parallel vs. cross printing, with and without polyurea). Three-point bending and splitting tensile tests were carried out, and the load-CMOD responses were analysed using the double-K fracture criterion and the work-of-fracture method. To quantify the contribution of the polyurea system, an energy-based modification factor kPU = G f,tot / G f,conc was introduced and linked, via a cohesive traction–separation model, to the tensile strength, ductility, thickness, and interfacial fracture energy of the polyurea layer. The results show that changing the printing path from parallel to cross alone increases the fracture energy by about 18.5 %, while the introduction of polyurea interlayers approximately doubles it. The bio-inspired cross-printed beams with polyurea achieve the highest fracture energy of 154.4 J/m2, representing an increase of about 167.7 % compared with conventional parallel-printed beams without polyurea. The initial cracking resistance and unstable fracture toughness are improved by 40 %–50 %, and the splitting tensile strength is also significantly enhanced. Both experimental and modeling analyses demonstrate that the synergistic action of the "brick-and-mortar" printing architecture and the polyurea-modified interfaces effectively inhibits unstable crack propagation through multi-scale energy dissipation, providing experimental evidence and mechanistic support for the fracture-oriented design of bio-inspired 3D-printed concrete beams. |
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