Abstract
Polyethylene pipes reinforced by winding steel wires (PSP) have been widely used in many fields such as chemical engineering, pulp conveying, water supply, etc. The combined loads of inner pressure and bending sometimes leads to the failure of PSP, and for engineering projects it is still not proposed that the failure criterion of PSP subject to combined loads. In this paper, full-size finite element models (FEM) of PSP under inner pressure and bending were established to investigate the engineering failure criterion. In the FEM the steel wires and HDPE matrix were modeled separately. The freedom degrees of steel wires and HDPE were coupled together as the interface between these two constituents were considered intact. The investigation contains two parts: firstly, a FEM was established in reference to the details of an existing experiment, including the pipe specimen and relative boundary condition. The validation of the FEM was carried out and the simulation result agreed well with test result indeed. Subsequently, the model was optimized to undertake four-point bending under inner pressure, to analyze the failure behavior of PSP under this kind of condition, with three factors such as varied ratio of diameters to thickness, inner pressure and volume ratio of steel wires. In the end, the curvature of failed PSP was considered as the failure criterion, and the relationship of curvature and the three factors were discussed. This paper is useful for the safety of PSP subject to inner pressure and bending load.