A numerical investigation into the behaviour of cracks in uPVC pipes under pressure
A numerical investigation into the behaviour of cracks in uPVC pipes under pressure
复制标题
uPVC管材在压力下裂纹行为的数值研究
DOI：
10.1061/41024(340)65
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发表时间：
2009
期刊：
影响因子：
5.1
通讯作者：
J. V. Zyl
中科院分区：
文献类型：
--
作者：
A. Cassa;J. V. Zyl
研究表明，水压对管道泄漏口泄漏率的影响是量化泄漏的主要因素。研究表明，网络中的泄漏指数与理论的孔板指数0.5有很大的不同。这意味着泄漏比以前认为的对压力更敏感，并且对压力和失水管理具有重要意义。虽然压力对圆孔泄漏指数的影响不显著，但对于纵向和周向裂纹，压力对其泄漏行为有较大影响。对于纵向裂纹，管道材料的纵向应力对泄漏指数的影响可以忽略不计，而对于周向裂纹，则相反。对于周向裂纹，在不存在纵向应力的情况下，对于小裂纹，管道泄漏指数保持在0.5附近，随着裂纹长度的增加，泄漏指数下降到0.5以下。利用有限元分析，该项目旨在找到管道变量和泄漏开口行为之间的关系。本研究的重点是纵向和周向裂纹及其在一定条件下的行为。它将集中于预测裂缝与管道各种变量的关系，并找到一个数值关系来预测裂缝的行为，然后从裂缝中发生的泄漏。一旦建立了这种关系，就可以用给定的一组参数来预测管道的行为和可能的泄漏。
Studies show that the effect of water pressure on the rate of leakage from leak openings in pipes is a major factor in quantifying leakage. Research shows how the leakage exponents in networks can differ substantially from the theoretical orifice exponent of 0.5. This means that leakage is more sensitive to pressure than previously believed and has significant implications for pressure and water loss management. Although the effect of pressure on the leakage exponent for circular holes is not significant, for the longitudinal and circumferential cracks pressure plays a large role in their leakage behaviour. For longitudinal cracks the longitudinal stresses in the pipe material have negligible effect on the leakage exponent, but the opposite is true for circumferential cracks. For the circumferential cracks it was found that in the absence of the longitudinal stresses the leakage exponent in the pipe remains close to 0.5 for small cracks and drops below 0.5 as the length of the crack increases. Using Finite Element Analysis the project aims to find a relationship between the variables of a pipe and the behaviour of the leak opening. This study focuses on longitudinal and circumferential cracks and their behaviour under certain conditions. It will concentrate on predicting the relationship of the crack versus the various variables of the pipe and find a numerical relationship to predict the behaviour of the crack, and then the leakage that will occur from the crack. Once this relationship is established it will be possible to predict the behaviour and possible leakage from a pipe with a given set of parameters.