Sun, He, Zhang
Lifetime Analysis # 2004 Milan
Steel mesh reinforced plastic pipe is an innovative type of pressure pipe which is composed of plastics with a steel mesh encased. Due to the big differences in respective mechanical properties of the two materials, the stresses sustained by them also differ greatly when the pipe is subject to load. The methods available so far to determine the maximum operating pressure of such pipes are rather time-consuming and complicated as with those methods a great number of PDB or MRP tests have to be conducted on all sizes of pipes. This paper develops a new method for pressure design of steel mesh reinforced plastic pipe. Theoretical analysis demonstrates that when the pipe is subject to allowable load, the two materials have the same deformation (strain), so the ratio of the stresses sustained by the two materials can be determined according to Hooke’s law. Thus the maximum pressure rating of the pipe can be expressed as the weighted summation of the strength of plastic and that of steel mesh, which can be obtained by using traditional pressure rating calculation formula. Results of calculations and PDB tests carried out on Dn50mm pipe samples show that this method is more conservative in terms of safety. This method can also be extended to be used for pressure design of other structurally similar composite pipes.