摘要:
本研究提出将负泊松比结构与超高韧性水泥基复合材料(ultra-high toughness cementitious composites, UHTCC)结合以提升防爆墙的抗爆性能，并通过爆炸试验与数值模拟相结合的方法，研究分析负泊松比靶板的抗爆性能，证明UHTCC负泊松比靶板的抗爆性能优越性。首先，利用混凝土3D打印技术实现负泊松比结构建造，并通过靶板接触爆炸试验结果验证有限元模型的可靠性。在此基础上，利用该有限元模型模拟分析了靶板材料、结构、胞元内凹角及实心层厚度占比等因素对接触爆炸下结构破坏形态与能量消耗的影响。结果表明：(1)具有高韧性的UHTCC靶板抗爆性能显著优于混凝土靶板；(2)三种结构中，负泊松比结构板吸能能力最强，实心板更能保持结构的完整性；(3)当负泊松比胞元内凹角为61°时抗爆性能最优，过小或过大均降低结构抗爆性；(4)负泊松比结构厚度占靶板总厚度过大时抗爆性能弱，结构破坏严重，可上下层同时或仅背爆面增加实心层厚度，在有效削弱爆炸冲击波、吸收能量的同时，提高结构完整性。研究验证了负泊松比UHTCC板抗爆性能优越性，并为基于负泊松比结构的防爆墙设计提供了理论依据。
Abstract:
In this study, it is proposed to combine the negative Poisson's ratio structure with ultra-high toughness cementitious composites (UHTCC) to improve the explosion resistance of the blast wall. And through a combination of the explosion experiment and numerical simulation, the anti-explosive property of the negative Poisson's ratio slab has been studied, in order to prove the superiority of the anti-explosive properties of the negative Poisson's ratio UHTCC slab. Firstly, the negative Poisson's ratio structure was constructed by using concrete 3D printing technology, and the finite element model is verified by the results of the contact explosion test. On this basis, the finite element model is used to simulate and analyze the effects of different materials of slabs, different structures of slabs, different cell concave angles and different solid layer thickness ratios on the structural damage patterns and the ability of energy absorption under contact explosion. The results show that: (1) Due to the high toughness, explosion resistance of UHTCC slabs is significantly better than the concrete slabs.The UHTCC slabs all remained intact and the concrete target slabs were all penetrated. (2) Negative Poisson's ratio slab has the best ability to absorb energy during three kinds of structures, while the solid slab is more able to maintain the structural integrity. (3) When the negative Poisson's ratio of the cell concave angle is 61° , the structure has optimal explosion resistance, and smaller and larger angle both reduce the explosion resistance of structure. (4) When the thickness of the negative Poisson's ratio structure is too large as a proportion of the total thickness, the slab is severely damaged. Increasing the solid layer thickness of the backburst surface of the slab or increasing the solid layer thickness of the explosion-facing surface and the backburst surface at the same time is conducive to weakening of the blast shock wave and improving structural integrity. This study confirmed the superiority of the explosion resistance of negative Poisson's ratio UHTCC slab, and provides a theoretical basis for the design of blast walls based on negative Poisson's ratio structure.
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