Novel Trenchless Local Rehabilitation Structure with Negative Poisson's Ratio for Pipelines: Experimental and Simulation Study

Abstract

Trenchless local rehabilitation technology is a commonly used repair technology for underground buried pipelines. However, existing methods have disadvantages such as slow restoration and poor adaptability. This paper proposes a trenchless local rehabilitation technology for buried pipelines based on circular auxetic tubes with rectangular perforations (CATRP) according to the working principle of vascular stents. The tensile mechanical response of CATRP is investigated using a combination of quasi-static tensile testing and finite element simulation, and the effects of geometric design parameters were considered. The results show that the designed auxetic tube has a significant auxetic effect. The auxetic effect increases with the increase of the length of the rectangular hole and the size of the boundary part, and increases with the decrease of the width of the rectangular hole, the thickness of the ligament, the outer diameter of the tube as well as the number of the cell distribution along the circumferential direction. In addition, the optimized tube achieves a peak stress of 1.53 MPa, which is about 41% lower, and the absolute value of Poisson's ratio (AVPR) reaches 0.81, which is about 47% higher, compared to the initially designed tube. The results of the study can provide a new reference and significant guidance for applying auxetic structures in local trenchless rehabilitation.

Keywords: Auxetic tube, Negative Poisson's ratio, 3D printing, finite element simulation, Deformation mechanism