Short-Term Mechanical Analysis of Polyethylene Pipe Reinforced by Winding Steel Wires Using Steel Wire Spiral Structural Model

Polyethylene pipe reinforced by winding steel wires (PSP) is a new type of polymer–matrix composite pipe that is widely used in petroleum, chemical engineering, and water supply, etc. PSP is composed of a high-density polyethylene (HDPE) core pipe, an outer cover layer (HDPE), and a steel wire skeleton sandwiched in the middle. The steel wire skeleton is formed by crossly winding steel wires integrated with HDPE matrix by cohesive resin. In traditional models, components of PSP are considered linear elastic and the steel wire skeleton is assumed to be an orthotropic composite layer based on classical laminated plate theory. Although satisfactory results can be achieved, traditional models neglect the material nonlinearity of the steel wires and HDPE matrix, which is an important consideration to failure analysis. In this study, a new finite element model was constructed based on the actual steel wire spiral structure of PSP. The steel wires and the HDPE matrix were modeled separately and were represented by solid elements. The steel wires were not in contact with each other, and the interaction between the steel wires and the HDPE matrix was characterized by tie constraint. Experimental result of short-term burst pressure of PSP was used to validate the nonlinear model. The calculation results of the nonlinear model agreed well with the experimental result. The effects of the nonlinear material property of components on the calculation results were investigated, and the short-term mechanical responses of PSP were analyzed through the nonlinear model.