Zeng Donghu, Iurzhenko Maksym, Demchenko Valeriy
Department of Plastics Welding, E.O. Paton Electric Welding Institute of the National Academy of Sciences of Ukraine, 03150 Kyiv, Ukraine.
Polymers (Basel). 2025 Jul 14;17(14):1932. doi: 10.3390/polym17141932.
Currently, the determination of the molten zone thickness in HDPE pipes during butt fusion welding primarily depends on experimental and numerical methods, leading to high costs and reduced efficiency. In this study, a mathematical (MM) model based on Neumann's solution for the melting of a semi-infinite region was developed to efficiently predict the average molten zone (AMZ) thickness of HDPE pipes under varying heating temperatures and heating times while incorporating the effects of heat convection. Additionally, a two-dimensional CFD model was constructed using finite element analysis (FEA) to validate the MM model. Welding pressure was not considered in this study. The effects of heating temperature, heating time, and heat convection on the AMZ thickness in HDPE pipes were systematically analyzed. The heating temperature at the heated end of HDPE ranged from 190 °C to 350 °C in 20 °C increments, with a temperature of 28 °C as the ambient and initial setting, and the heating time was set to 180 s for both the MM and CFD models. The results demonstrate a strong correlation between the AMZ thickness predictions from the MM and CFD models. The relative error between the MM and CFD models ranges from 0.280% to 10,830% with heat convection and from -2.398% to 8.992% without heat convection. Additionally, for the MM model, the relative error between cases with and without heat convection ranges from 0.243% to 0.433%, whereas for the CFD model, it varies between 1.751% and 3.189%. These findings confirm the reliability of the MM model developed in this study and indicate that thermal convection has a minimal impact on AMZ thickness prediction for large-diameter, thick-walled HDPE pipes.
目前，对接热熔焊接过程中高密度聚乙烯（HDPE）管材熔化区厚度的测定主要依赖于实验和数值方法，这导致成本高昂且效率低下。在本研究中，基于半无限区域熔化的诺伊曼解开发了一个数学（MM）模型，以在考虑热对流影响的情况下，有效预测不同加热温度和加热时间下HDPE管材的平均熔化区（AMZ）厚度。此外，使用有限元分析（FEA）构建了二维计算流体动力学（CFD）模型来验证MM模型。本研究未考虑焊接压力。系统分析了加热温度、加热时间和热对流对HDPE管材AMZ厚度的影响。HDPE加热端的加热温度以20℃为增量，范围从190℃到350℃，环境温度和初始设定温度为28℃，MM模型和CFD模型的加热时间均设定为180秒。结果表明，MM模型和CFD模型对AMZ厚度的预测具有很强的相关性。有热对流时，MM模型和CFD模型之间的相对误差范围为0.280%至10830%，无热对流时为-2.398%至8.992%。此外，对于MM模型，有热对流和无热对流情况之间的相对误差范围为0.243%至0.433%，而对于CFD模型，该误差在1.751%至3.189%之间变化。这些发现证实了本研究中开发的MM模型的可靠性，并表明热对流对大口径、厚壁HDPE管材的AMZ厚度预测影响极小。
