Analysis On Ultimate Strength Of The Plastic Pipe Reinforced By Cross Helically Winding Steel Wires (PSP)

PSP is a new kind of composite pipe and it is composed of two pure polyethylene layers and several composite layers reinforced by steel wires. The inner linner and external coating are both made up of high density polyethylene and formed by heat extrusion. While a high-strength steel wire mesh skeleton is sandwiched between the liner and an outer polyethylene coating. The matrix can not only carry part of external force but also have excellent corrosion resistance. While steel wire skeleton will sustain most of internal pressure loading. Compared with other composite pipe, PSP has high manufacture efficiency and strong interfacial adhesion and has been developed rapidly in China recently.Analysis on ultimate strength of PSP has been did through four approach(mathematical, finite element, testing and engineering formula). Defect due to uncertainties during manufacturing and service procedure was researched and the effect of defect on mechanical properties was put forward. Finally dynamic response numerical simulation of PSP under ramming impact loading is put forward. The main work is as follows:Based on the structure of PSP, multi-plane stress model is put forward. The reinforced layer is simplified as a kind of cross-isotropic material. Using MATLAB language, the mechanical characteristics of each layers was gotten under pure internal pressure and compared with the results by abaqus finite element software.Using force balance method, the engineering formula was derived to predict burst pressure. Compared with the results of mathematic, finite element and burst test, it is found that the formula is full of high accuracy. Using FORM design approach, design reliable factors of burst pressure was gotten in different working conditions.Make different defects analysis of PSP to research influence of lacking of steel wires, interface separation and structural damage of outer PE layer to ultimate strength.A three dimensional model was established to simulate the dynamic response of buried pipe under tamping impact load. Analysis the impact energy, embedment depth and horizontal distance between rammer and pipe etc to find their impact on buried PSP.