厚壁聚乙烯管热熔焊接力学性能影响机制建模与仿真研究OA

Based on the theories of polymer crystallization kinetics and molecular chain reptation,this study elucidates the microstructural mechanisms governing butt fusion welding in polyethylene(PE)pipes.It identifies the initial tempera-ture field at the welding interface,and its dynamic evolution,as the central factor dictating the mechanical integrity of the welded joint.By approximating the interfacial thermal behavior as a two-dimensional heat transfer model,a quantitative relationship was established between key process parameters and the spatiotemporal distribution of the temperature field throughout the welding cycle.Using thermal simulation software and a controlled-variable methodology,the study sys-tematically quantified the effects of ambient conditions,including ambient temperature,wind speed,and heat source re-moval time,on the peak temperature and minimum interface temperature during welding.The research demonstrates that interfacial forces play a dominant role in shaping the initial temperature field.Furthermore,it reveals a nonlinear cou-pling between the maximum temperature in the molten zone and the minimum temperature at the interface.Notably,sin-gularities in the temperature gradient were observed during the dynamic evolution of the thermal field in thick-walled pipes under varying environmental conditions,phenomena not previously reported in the literature.These findings pro-vide a robust theoretical foundation for optimizing both welding protocols and on-site environmental controls in the fabri-cation of thick-walled PE pipe joints,ultimately enhancing weld quality and structural reliability.