钢-UHTCC组合桥面板焊接细节应力幅数值分析

Numerical Analysis on Stress Ranges in Welding Details of Steel-UHTCC Composite Bridge Decks

为研究钢-超高韧性水泥基复合材料(UHTCC)组合桥面板的疲劳性能,开展了肋-顶板、横隔-顶板和栓钉-顶板焊接细节的应力幅数值分析。采用有限元软件Abaqus建立了钢-UHTCC组合桥面板精细化有限元模型,计算了疲劳车荷载作用下焊接细节部位的应力幅。定量分析了3个关键设计参数对应力幅的影响,包括UHTCC层的厚度、剪力钉的布置密度和纵向板肋的数量。结果表明:增加UHTCC层厚度对肋-顶板焊接细节应力幅降低效果最明显,在疲劳单车荷载作用于其中1跨的跨中时,UHTCC层厚度从0 mm增加到40 mm,肋-顶板和横隔-顶板焊接细节应力幅分别降低61.3%和33.2%;当疲劳单车荷载作用于跨中支座处时,提高纵向板肋数量对栓钉-顶板和肋-顶板焊接细节应力幅的影响相对较大,当纵向板肋个数从3增加到5时,栓钉-顶板和肋-顶板焊接细节应力幅分别降低70.9%和45.7%;当疲劳单车荷载作用于其中1跨的跨中时,提高栓钉布置密度和增加板肋数量分别对栓钉-顶板和肋-顶板焊接细节应力幅降低效果最明显,当栓钉布置密度从5个/m2提高到25个/m2时,栓钉-顶板和肋-顶板焊接细节应力幅分别降低74.2%和35.5%;当纵向板肋个数从3增加到5时,肋-顶板和横隔-顶板焊接细节应力幅分别降低49.5%和35.8%。

To investigate the fatigue properties of steel-UHTCC composite bridge decks,the numerical analysis of stress ranges in rib-to-deck,diaphragm-to-deck and stud-to-deck welding details is conducted.The refined finite element models of steel-UHTCC composite bridge decks are established by FE software Abaqus,and the stress ranges of the welding details under fatigue vehicle load are calculated.Then,the influence of 3 key design parameters(thickness of UHTCC layer,density of shear studs,and number of longitudinal plate-ribs)on stress ranges is quantitatively analysed.The result shows that(1)Increasing the thickness of UHTCC layer has the most obvious influence on reducing the stress ranges of rib-to-deck welding details.When the fatigue vehicle load acting on the middle of one span,as the thickness of UHTCC layer increases from 0 mm to 40 mm,the stress ranges of rib-to-deck and diaphragm-to-deck welding details drops by 61.3%and 33.2%respectively.(2)When the single fatigue vehicle load acting on the midspan support,increasing the number of longitudinal plate-ribs has relatively great influence on the stress ranges of stud-to-deck and rib-to-deck welding details.As the number of plate-ribs increases from 3 to 5,the stress ranges of stud-to-deck and rib-to-deck welding details drops by 70.9%and 45.7%respectively.(3)When the single fatigue vehicle load acting on the middle of one span,increasing the density of studs and the number of plate-ribs has the most obvious influence on reducing the stress ranges of stud-to-deck and rib-to deck welding details respectively.As the density of studs increases from 5/m2 to 25/m2,the stress ranges of stud-to-deck and rib-to-deck welding details drops by 74.2%and 35.5%respectively.(4)As the number of plate-ribs increases from 3 to 5,the stress ranges of rib-to-deck and diaphragm-to-deck welding details drops by 49.5%and 35.8%respectively.