A Numerical Investigation into the Behaviour of Cracks in uPVC Pipes under Pressure

Studies show that pressure has a major impact on the rate of leakage from leak openings in pipes, and that the leakage exponents in a real network can be substantially larger than the theoretical orifice exponent of 0.5. The most important reason for this behaviour is that leak areas are not fixed, but increase with increasing pressure. In this study, Finite Element Analysis was used to study the relationship between pressure and leak area in different pipes with longitudinal and circumferential cracks. It was found that both longitudinal and circumferential crack areas increase linearly with pressure. The slope of this linear relationship depends on various parameters, including the loading state, pipe dimensions and pipe material properties. The impact of the different parameters on the pressure-area slope was investigated, and an attempt will be made to find an expression to express the pressure-area slope as a function of the parameters. If such a relationship can be established, it will be possible to predict the behaviour of different types of leak openings in different pipes and pipe materials.