钢箱梁面板-纵向腹板构造细节轮载应力的参数分析

Parametric Analysis of Stress at Detail of Deck Plate to Inner Longitudinal Web of Steel Box Girder under Wheel Loads

为研究轮载作用下结构参数对钢箱梁桥面板-纵向腹板构造细节应力响应的影响,建立了带纵向腹板的正交异性钢桥面板有限元模型,并基于我国规范对疲劳车模型开展了研究。首先针对轮载在横桥向的5种典型位置,通过每种位置轮载的顺桥向移动,获得了面板-纵向腹板构造细节及其附近面板-纵肋构造细节的应力响应,通过对比分析确定了面板-纵向腹板构造细节的最不利轮载工况。然后,在该最不利轮载工况下,分析了纵向腹板3个主要设计参数变化对面板-纵向腹板构造细节的应力响应影响。研究表明:与其他横桥向轮载位置相比,当轮载中心位于纵向腹板正上方时,面板-纵向腹板构造细节的面板侧将产生最大的应力响应;纵向腹板与相邻纵肋腹板间距的变化对该构造细节的应力影响显著,但纵向腹板厚度及其与面板间的夹角对该构造细节的应力影响很小;基于传统的正交异性钢桥面板设计,纵向腹板的厚度可为12 mm,其与相邻闭口纵肋腹板的间距建议不大于150 mm,而纵向腹板宜与面板成正T形或接近正T形焊接。基于构造细节最不利轮载工况开展的有限元分析表明:采用上述建议结构参数设计的面板-纵向腹板构造细节,能有效降低该构造细节的应力,因而能提高其疲劳性能。

In order to evaluate the effects of structural parameters on stress response at the detail of inner longitudinal web to deck plate of steel box girder under wheel loading,a finite element model of OSBD with longitudinal webs is established,and the study is conducted using the fatigue truck model specified in Chinese specification.'First,considering 5typical transverse wheel loading locations,the stress responses at both deck to inner longitudinal webs and adjacent longitudinal rib to deck connection details under the passage of each wheel load moving in longitudinal direction are obtained and compared to determine the most unfavorable loading case for stress at unfavorable loading studied.It is found case,the influence that (1)when the the detail of deck to longitudinal webs.Then,under the most of 3major design parameters on the stress variation at the detail is wheel loading center is directly above the inner longitudinal web in transverse direction,highest stress response at the deck side of the detail would be produced compared to other transverse wheel loading locations;(2)the space between the inner longitudinal web and the adjacent U-rib web presents notable effect on the stress response at the detail,but the thickness of the inner longitudinal web and its angle to the deck plate do not show significant effects on the stress response at the detail.(3)under traditional engineering practice of.orthotropic steel deck,the thickness of inner longitudinal Web is 12mm ;the space of less than 150mm between the inner longitudinal web and the adjacent U-rib web,and right or almost right-angle weldifig of inner longitudinal web to the deck plate are suggested.The FE analysis of the detail under the critical wheel loading condition shows that,the stress response can be greatly reduced at the detail of deck to inner longitudinal web with the suggested structural parameters,and hence the fatigue performance at the detail can be improved.