环境湿度影响下大尺寸结构预应力损失及挠度变化的多场多尺度分析  

Multi-Physics and Multi-Scale Analysis of Prestress Loss and Deflection in Large-Scale Structures Under the Influence of Environmental Humidity

作　　者：弓扶元 黄哲 潘钻峰[2] 赵羽习[1] 曾滨[3] GONG Fuyuan;HUANG Zhe;PAN Zuanfeng;ZHAO Yuxi;ZENG Bin(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Central Research Institute of Building and Construction Co.,Ltd.,MCC Group,Beijing 100088,China)

机构地区：[1]浙江大学建筑工程学院,杭州310058 [2]同济大学土木工程学院,上海200092 [3]中冶建筑研究总院有限公司,北京100088

出　　处：《工业建筑》2024年第10期21-30,共10页Industrial Construction

基　　金：国家重点研发计划项目(2022YFC3801800)。

摘　　要：预应力结构作为桥隧结构的主要构件常服役于高湿或变湿环境,为了研究预应力梁在不同环境湿度下的长期变形发展及长期预应力损失,基于DuCOM-COM3多场多尺度有限元计算程序对不同环境湿度下的预应力混凝土结构进行了有限元分析,并与试验结果进行对比,结果表明:混凝土梁的预应力损失受到环境湿度的影响,环境湿度增大有利于减小构件的长期变形从而减缓预应力结构的预应力损失与长期挠度。这表明基于多尺度微观孔隙结构的材料本构可以考虑孔隙结构的微观变形,通过计算混凝土材料内部的微观行为和水分传输可以得到混凝土结构的力学性能。通过对比试验与计算证明了混凝土结构的多场多尺度分析能分析变化的环境对预应力混凝土结构的长期性能的影响。通过水-热-力学耦合的多场多尺度分析机理,模拟环境湿度为40%、60%以及80%情况下的预应力混凝土梁的预应力损失与长期挠度情况。得出环境湿度大小与收缩、徐变以及长期变形、预应力损失情况之间的关系。Prestressed structures,serving as key components in bridge and tunnel construction,frequently operate in high or variable humidity environments.To investigate the long-term deformation and prestress loss of prestressed beams under varying environmental humidities,this study employed the DuCOM-COM3 multi-physis and multi-scale finite element program to analyze prestressed concrete structures across different humidity levels and compared these findings with experimental results.The findings indicated that concrete beam prestress loss was influenced by environmental humidity;higher humidity reduced long-term deformation,thereby mitigating prestress loss and long-term deflection in these structures.This suggests that constitutive models based on multi-scale micro-pore structures could capture the micro-deformations within pore structures,enabling the determination of concrete structures’mechanical properties through computations of micro-behavior and moisture transport within the concrete.Comparative experiments and calculations demonstrated that multi-field and multi-scale analysis of concrete structures could assess the effects of changing environments on the long-term performance of prestressed concrete structures.Through analyzing the mechanism of multi-physics and multi-scale analysis of moisture-heat-stress coupling,the paper simulated the prestress loss and long-term deflection of prestressed concrete beams under environmental humidity conditions of 40%,60%,and 80%.The relations between environmental humidity and the shrinkage and creep,the long-term deformation,and the prestress loss were obtained.

关 键 词：预应力损失 大尺寸结构 多场多尺度 环境湿度 收缩-徐变 

分 类 号：U441[建筑科学—桥梁与隧道工程]