The Strength Analysis Of Plastic Pipe Reinforced By Cross-winding Steel Strands Tape

Thermoplastic plastic pipe reinforced by cross-winding steel strands tape(s-RTP) is anew type plastic-matrix steel strands composite pipe. S-RTP is composed of two layers ofthermoplastic high density polyethylene(HDPE) matrix and a high strength steel strandstape, which is sandwiched in the middle of the inner and outer HDPE layers. Steel strandstape is made from high strength steel strands and molten HDPE. The steel strands tape isover wrapped on the surface of the HDPE liner pipe, under a negative and a positive angle,respectively. An outer cover layer is extruded over the structure. Hosing steel strands as theenhanced material, which made s-RTP has better flexibility than others steel skeletonreinforced plastic pipe. Because of steel strands tape is made from high strength steelstrands and molten HDPE, which made the production process simplified, the uniformity ofsteel strands in s-RTP improved, the production efficiency enhanced. So, s-RTP could beutilized widely in various fields.At present, research on s-RTP, mostly stayed on production, installation, manufacturing.The study of the strength analysis of s-RTP stayed in experimental and theoretical research.In order to promot the development, improve the performance and ensure the securityoperation of s-RTP. It is necessary to do a series of experimental and theoretical studies.In this study, a method of modeling the mechanical behavior of s-RTP under internalpressure was put forward,using the finite element software ANSYS, established themechanics model of s-RTP, and made the strength analysis, parameter analysis and defectanalysis. The main work was shown, as below:(1) Analysis the structure characteristics of s-RTP, established the parameteritis model,chose the appropriateKinematic hardening model of steel strands and HDPE and determinethe relevant physical parameters by specific tensile experiment, then, analysis the meshingmethod, boundary constraints and loading test scheme. Satisfactory agreement betweennumerical and experimental burst pressure value, showed that the model set out in presentarticle could accuratelyforecast the burst pressure value of s-RTP. So, the model establishedin this paper was appropriate, it was convincible to explore the other related conclusions. (2) Analysis the numerical load-displacement vector sum contour plot of s-RTP andsteel strands, analyze the numerical load-displacement vector sum contour plot of steelstrands in Z direction, when s-RTP was subjected to the burst pressure loading.At the sametime, the numerical load-plastic strain curve under internal pressure of the node in theinnermost of the section located in the mid-section in Z direction was analysis, got theelastic deformation limiting pressure of s-RTP.(3) Ansysis the influence of different parameters (the Elasticity Modulus of steelstrands, the number of steel strands, the layers of composite layer, the thickness of innerHDPE and outer HDPE) to the burst pressure and elastic deformation limiting pressure ofs-RTP, determine the main influence.(4) Make the defect analysis of s-RTP, analysis the influence of the monolayer anddouble-layer lacking of steel strands to the strength of s-RTP, got the variation tendency ofthe burst pressure and elastic deformation limiting pressure with the vary of monolayer anddouble-layer lacking of steel strands.