Analysis of explosion resistance of the blast wall with negative Poisson's ratio Structure

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.