为提升预应力钢筒混凝土管断丝辨识精度,研究首先利用分布式光纤声学感知技术采集断丝信号,并使用连续小波变换算法提取信号时频特征图谱。随后,设计了一种结合分布式光纤声学感知技术和改进You Only Look Once version 5(YOLOv5)的预...为提升预应力钢筒混凝土管断丝辨识精度,研究首先利用分布式光纤声学感知技术采集断丝信号,并使用连续小波变换算法提取信号时频特征图谱。随后,设计了一种结合分布式光纤声学感知技术和改进You Only Look Once version 5(YOLOv5)的预应力钢筒混凝土管断丝智能辨识方法。将提出的智能辨识方法进行性能分析,实验结果表明,该方法的平均精度和准确率分别为97.39%和98.02%,均优于对比方法。研究结果表明,提出的预应力钢筒混凝土管断丝辨识方法具有良好的性能,能为相关水利工程运维和管理提供理论基础。展开更多
Buried prestressed concrete cylinder pipes(PCCPs)are subjected to the combined effects of soil cover loads,internal water pressure,and additional loads.However,there is scarce research on their mechanical performance ...Buried prestressed concrete cylinder pipes(PCCPs)are subjected to the combined effects of soil cover loads,internal water pressure,and additional loads.However,there is scarce research on their mechanical performance under complex service conditions after being buried.In this study,3D nonlinear finite element(FE)models of PCCPs and soils,along with fluid models,were developed using ABAQUS and FLUENT,respectively.Fluid-solid coupling numerical simulations of PCCPs with broken wires under complex service conditions were conducted using the MpCCI platform.The study focused on investigating the mechanical behaviors of PCCP pipes with broken wires,aiming to determine the effects of different numbers and locations of broken wires,as well as the magnitude of operating water pressure.The results shows that the number of broken wires is a crucial factor affecting the mechanical behaviors of the PCCPs;the dynamic variation of internal pressure within the pipe can cause further damage to PCCPs with pre-existing defects;when wire breakage occurs alone the springline of the PCCPs,the outer concrete core exhibited a tendency to crack before the inner concrete core.Conversely,when wire breaks occurred at the crown and invert,the inner concrete core cracked before the outer concrete core.These results provide valuable insights into the behavior of PCCPs under complex conditions and contribute to the understanding of their structural integrity.The findings can aid in the development of improved design and maintenance strategies for PCCPs,ensuring their reliable performance in underground applications.展开更多
文摘为提升预应力钢筒混凝土管断丝辨识精度,研究首先利用分布式光纤声学感知技术采集断丝信号,并使用连续小波变换算法提取信号时频特征图谱。随后,设计了一种结合分布式光纤声学感知技术和改进You Only Look Once version 5(YOLOv5)的预应力钢筒混凝土管断丝智能辨识方法。将提出的智能辨识方法进行性能分析,实验结果表明,该方法的平均精度和准确率分别为97.39%和98.02%,均优于对比方法。研究结果表明,提出的预应力钢筒混凝土管断丝辨识方法具有良好的性能,能为相关水利工程运维和管理提供理论基础。
基金supported by the National Key R&D Program of China(2022YFC3801000)the National Natural Science Foundation of China(52208375)+2 种基金the Postdoctoral Science Foundation of China(2022TQ0305,2022M722884)the Youth Talent Promotion Project of Henan Province(2023HYTP016)the Key Specialized Research and Development Breakthrough in Henan Province(232102321073,232102321014).
文摘Buried prestressed concrete cylinder pipes(PCCPs)are subjected to the combined effects of soil cover loads,internal water pressure,and additional loads.However,there is scarce research on their mechanical performance under complex service conditions after being buried.In this study,3D nonlinear finite element(FE)models of PCCPs and soils,along with fluid models,were developed using ABAQUS and FLUENT,respectively.Fluid-solid coupling numerical simulations of PCCPs with broken wires under complex service conditions were conducted using the MpCCI platform.The study focused on investigating the mechanical behaviors of PCCP pipes with broken wires,aiming to determine the effects of different numbers and locations of broken wires,as well as the magnitude of operating water pressure.The results shows that the number of broken wires is a crucial factor affecting the mechanical behaviors of the PCCPs;the dynamic variation of internal pressure within the pipe can cause further damage to PCCPs with pre-existing defects;when wire breakage occurs alone the springline of the PCCPs,the outer concrete core exhibited a tendency to crack before the inner concrete core.Conversely,when wire breaks occurred at the crown and invert,the inner concrete core cracked before the outer concrete core.These results provide valuable insights into the behavior of PCCPs under complex conditions and contribute to the understanding of their structural integrity.The findings can aid in the development of improved design and maintenance strategies for PCCPs,ensuring their reliable performance in underground applications.
