Abstract Plastic/viscoelastic pipes, such as polyvinyl chloride (PVC), polyethylene (PE) and high-density polyethylene (HDPE), have been increasingly used in water piping systems, which has stimulated the study of viscoelastic hydrodynamics in these pipe systems. An in-depth understanding of the pipe-wall viscoelasticity features is beneficial and necessary to the effective application and management of plastic pipes such as leak detection in urban water supply systems. This paper presents a frequency response function (FRF)-based transient wave analysis method (TWAM) for the identification of viscoelastic pipe properties as well as the detection of leaks in water filled plastic pipes. To this end, an analytical FRF expression is firstly derived for the interaction of transients with pipe-wall elasticity and leaks in plastic pipes, which is thereafter used for the identification of viscoelastic parameters and potential leaks in plastic pipes. Laboratory experiments are performed to validate the proposed FRF-based TWAM and thereby examining the effective range of injected wave bandwidth for accurate leak detection with existence of pipe-wall viscoelasticity. The validated method is further analyzed through extensive numerical applications to systematically examine the influences of different system and flow conditions. Application results confirm the feasibility and accuracy of the developed FRF-based TWAM method for the identification of viscoelastic parameters as well as the detection of plastic pipe leaks. The results also indicate that the proposed method in this study is more accurate to locate leaks than to size leaks in plastic pipes, which requires more attention to the future applications.

中文翻译：

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基于 FRF 的瞬态波分析用于充水塑料管的粘弹性参数识别和泄漏检测

摘要 塑料/粘弹性管道，如聚氯乙烯 (PVC)、聚乙烯 (PE) 和高密度聚乙烯 (HDPE)，越来越多地用于水管道系统，这刺激了这些管道系统中粘弹性流体动力学的研究。深入了解管壁粘弹性特性对于塑料管道在城市供水系统中的泄漏检测等有效应用和管理是有益和必要的。本文提出了一种基于频率响应函数 (FRF) 的瞬态波分析方法 (TWAM)，用于识别粘弹性管道特性以及检测充水塑料管道中的泄漏。为此，首先推导出瞬态与管壁弹性和塑料管道泄漏的相互作用的分析 FRF 表达式，此后用于识别塑料管道中的粘弹性参数和潜在泄漏。进行实验室实验以验证所提出的基于 FRF 的 TWAM，从而检查注入波带宽的有效范围，以便在管壁粘弹性存在的情况下进行准确的泄漏检测。通过广泛的数值应用进一步分析验证的方法，以系统地检查不同系统和流动条件的影响。应用结果证实了开发的基于 FRF 的 TWAM 方法在粘弹性参数识别以及塑料管道泄漏检测方面的可行性和准确性。结果还表明，本研究中提出的方法在定位泄漏方面比在塑料管道中确定泄漏尺寸更准确，