预应力CFRP加固钢结构的裂纹扩展双参数驱动力模型  

Two-parameter Crack Driving Force Model for Crack Growth of Damaged Steel Structures Strengthened with Pre-stressed CFRP

作　　者：叶华文[1] 唐诗晴 刘德军 周渝 刘吉林 YE Hua-wen;TANG Shi-qing;LIU De-jun;ZHOU Yu;Liu Ji-lin(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,Sichuan,China;College of Civil Engineering&Architecture,Jiaxing University,Jiaxing 314001,Zhejiang,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]嘉兴学院建筑工程学院,浙江嘉兴314001

出　　处：《中国公路学报》2022年第2期193-200,共8页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51208430);浙江省自然科学基金项目(LY19E080016);浙江省教育厅一般科研项目(Y201840370)。

摘　　要：预应力CFRP是一种高效的加固损伤钢结构的新型方法,疲劳裂纹扩展驱动机制是评估疲劳寿命和CFRP加固效果的基础。为研究预应力CFRP板加固受损钢结构的裂纹扩展机理,从单调拉伸损伤和循环损伤耦合机制出发,考虑裂纹闭合效应,提出了一种新型双参数驱动力模型ΔK^(1-γ)_(eff)K^(γ)_(max)。然后基于实测裂纹扩展数据,联合采用软件ANSYS和裂纹扩展分析软件Franc3D建立空间有限元模型,应用新双参数驱动力模型模拟轴拉钢板的裂纹扩展行为,疲劳断口分析的预测值与实测值对比表明:所提出的驱动力模型ΔK^(1-γ)_(eff)K^(γ)_(max)能合理反映裂纹扩展行为。最后应用该驱动力模型在不同应力比条件下对轴拉钢板、工字梁和矩形管梁等典型受力构件的裂纹扩展进行分析,结果表明:相较于传统的裂纹闭合模型和双参数驱动力模型,ΔK^(1-γ)_(eff)K^(γ)_(max)的裂纹扩展预测在各种应力比情况下更精确,可供预应力CFRP加固钢结构的疲劳裂纹扩展分析和寿命评估参考。An innovative strengthening technique using external post-tensioned CFRP proved to be highly effective in improving the fatigue performance of aged steel members.The crack driving mechanism is the foundation of the evaluation of fatigue life and CFRP reinforcement.Considering the interplay of monotonic and cyclic damages as well as the crack closure effect,a new two-parameter crack driving force model is presented to investigate the crack growth mechanism of damaged steel structures strengthened with pre-stressed CFRP plates.Using ANSYS and Franc3D,the crack growth was simulated using the new driving force model based on experimental crack growth data of the steel tensile plate.The fractographic analysis validated the crack propagation simulation usingΔK^(1-γ)_(eff)K^(γ)_(max).Furthermore,the proposed model was used to predict the crack growth curves of the steel tensile plates,I-beams,and rectangular tube beam members under different stress ratios.The results show that the proposed model provides a more accurate prediction than the traditional ones(i.e.,the crack closure model and former two-parameter force model)under various stress ratios.This refers to the fatigue crack evaluation and life estimation of damaged steel structures strengthened with pre-stressed CFRP.

关 键 词：桥梁工程 预应力CFRP板 裂纹扩展 钢结构 双参数驱动力 应力比 

分 类 号：U441[建筑科学—桥梁与隧道工程]