正交异性钢桥面板带裂纹工作性能

Performance of Orthotropic Steel Deck with Embedded Fatigue Cracks

摘要:

给出了典型轮载作用下带裂纹正交异性钢桥面板及铺装层的响应、疲劳寿命等相较于无裂纹工况的变化，发现裂纹未完全贯通顶板时对结构局部刚度影响较小，仅当完全贯通裂纹尺寸达一定程度时才导致结构竖向位移显著增大。然而，即使顶板未被贯通，裂纹仍将引发铺装层底部应变集中，导致其寿命明显降低。基于铺装层应变?寿命关系，估计当裂纹深度达顶板厚度的1/2、3/4时，可使得铺装层寿命分别降低约15%、35%。

关键词:桥梁工程;正交异性钢桥面板;数值模拟;疲劳损伤;裂纹行为

Abstract:

By embedding these cracks on the model， the effects on the structural responses and fatigue life of the cracked orthotropic steel deck （OSD） and the pavement are presented with comparison to the crack-free condition. The results show that a penetrating crack can hardly affect the local stiffness before it completely penetrates thorough the deck plate and grows to a considerable length. However， the penetrating crack will always be a problem as it may lead to the strain concentration at the bottom of the pavement， resulting in a significant reduction of its fatigue life. Based on the strain-life relationship of the pavement， it is estimated that when the depth of the cracks reaches 1/2 and 3/4 of the deck plate thickness， the pavement fatigue life can be reduced by about 15% and 35%， respectively.

Key words:bridge engineering;orthotropic steel deck(OSD);numerical simulation;fatigue damage;crack behavior