【摘要】：正交異性鋼橋面板發(fā)展面臨的主要問題在于良好的受力性能與高疲勞病害風險之間的矛盾,其中頂板與縱肋焊接構造細節(jié)是正交異性鋼橋面板疲勞病害危害最為嚴重的部位之一。從傳統(tǒng)正交異性鋼橋面板本身結構體系出發(fā)來改善其疲勞性能,雖然取得了一定的進展,但這一部位的疲勞病害案例仍然不斷涌現(xiàn)。在傳統(tǒng)正交異性鋼橋面板的基礎上,通過改進創(chuàng)新得到的結構形式來改善結構的疲勞性能,是促進正交異性鋼橋面板應用并推動其可持續(xù)發(fā)展的可行途徑之一。以新型鐓邊U肋正交異性鋼橋面板為研究對象,開展了以下幾個方面進行研究工作:(1)簡要概述了正交異性鋼橋面板的發(fā)展歷程,疲勞問題的產生原因及疲勞分析的基本理論和相關基本概念。介紹了新型結構的研究現(xiàn)狀,引入新型鐓邊U肋正交異性鋼橋面板,闡述了其提出背景和設計理念。(2)對缺口應力法進行了全面的介紹,詳細闡述了缺口應力法的理論基礎,總結了缺口應力法的特點及與名義應力法、熱點應力法的異同。討論了影響缺口應力法的關鍵因素:疲勞缺口系數(shù),疲勞壽命曲線以及缺口應力求解方法。(3)分析正交異性鋼橋面板各構造細節(jié)參數(shù)對缺口應力及疲勞缺口系數(shù)的影響,結果表明:增大頂板厚度可以有效改善頂板與縱肋焊接構造細節(jié)各疲勞關注細節(jié)的應力集中情況,增大U肋厚度主要減小U肋焊趾處應力,開口角度對頂板焊趾處應力影響最顯著,而增大焊縫熔深對焊根處應力集中有所改善。相關結論可為提高鋼橋面板的疲勞性能作參考。(4)對頂板與縱肋焊接構造細節(jié)已有疲勞試驗的名義應力數(shù)據(jù)進行再分析,并轉換為對應的缺口應力。結果表明缺口應力疲勞數(shù)據(jù)均位于ⅡW推薦的FAT225曲線之上,因此缺口應力法可以很好地應用在該構造細節(jié)的疲勞評價中。(5)采用缺口應力法對新型鐓邊U肋正交異性鋼橋面板疲勞壽命進行了評估,并對相關關鍵問題進行了研究。結果表明:缺口應力可以作為焊根或焊趾疲勞性能的有效評估指標,判別其疲勞性能的差異,相對而言,焊根處更易萌生裂紋;新型鐓邊U肋相較于傳統(tǒng)U肋,可以較好的改善該構造細節(jié)頂板焊趾及U肋焊趾處疲勞性能,但對焊根處應力改善效果不顯著。
[Abstract]:The main problem in the development of orthotropic steel bridge is the contradiction between good mechanical performance and high fatigue risk. The structural details of roof and longitudinal rib welding are one of the most serious fatigue damage parts of orthotropic steel bridge panel. Although some progress has been made in improving fatigue performance of orthotropic steel bridge panels from the traditional structural system of orthotropic steel bridges fatigue disease cases in this area are still emerging. On the basis of the traditional orthotropic steel bridge panel, it is one of the feasible ways to promote the application of orthotropic steel bridge panel and promote its sustainable development to improve the fatigue performance of the structure by improving the structure form obtained by innovation. Taking the new upsetting U-rib orthotropic steel bridge face as the research object, the following aspects of the research work are carried out: (1) the development of orthotropic steel bridge panel is briefly summarized. The causes of fatigue problems and the basic theory and related concepts of fatigue analysis. This paper introduces the research status of the new structure, introduces the new upsetting U-rib orthotropic steel bridge panel, expounds its background and design idea. (2) the notched stress method is introduced comprehensively, and the theoretical basis of the notched stress method is expounded in detail. The characteristics of notch stress method and its similarities and differences with nominal stress method and hot stress method are summarized. The key factors affecting notch stress method, such as fatigue notch coefficient, fatigue life curve and notch stress solution method, are discussed. (3) the influence of structural detail parameters on notch stress and fatigue notch coefficient of orthotropic steel bridge face is analyzed. The results show that increasing the thickness of roof can effectively improve the stress concentration of fatigue detail of roof and longitudinal rib welding structure, and increase the thickness of U rib to decrease the stress at the toe of U-rib welding. The effect of the opening angle on the stress at the toe is the most significant, while the stress concentration at the root is improved by increasing the weld penetration. The relevant conclusions can be used as a reference for improving the fatigue performance of steel bridge slabs. (4) the nominal stress data of fatigue tests on the structure details of roof and longitudinal rib welding have been reanalyzed and converted into corresponding notch stresses. The results show that the notch stress fatigue data are above the FAT225 curve recommended by 鈪，

本文編號：2189177