钢桥面板横隔板新型开孔构造细节疲劳寿命评估

Assessment on Fatigue Life of New Perforated Structure Details for Diaphragms of Steel Bridge Deck

摘要:

为研究钢桥面板横隔板新型开孔构造细节的疲劳性能，借助实体有限元软件，对潜在疲劳裂纹萌生点扩展情况进行了数值模拟。在同一加载条件下，横隔板单孔形式纵肋腹板围焊焊趾处的疲劳应力为51.4 MPa，新型开孔形式纵肋腹板和纵肋底板围焊焊趾处的疲劳应力分别为5.1 MPa和39.6 MPa，可见新型开孔形式导致的疲劳应力较小；以裂纹扩展至板厚1/2为疲劳失效判据，横隔板单孔形式和新型开孔形式疲劳寿命分别为356万次和1 833万次，说明新型开孔形式在疲劳性能上具有显著优势。

Abstract:

In order to study the fatigue performance of a new perforated structure details for diaphragms of the steel bridge deck, the potential propagation of fatigue crack initiation points is numerically simulated by using the solid finite element software. Under the same loading conditions, the fatigue stress at the weld toe around the longitudinal rib web in the single hole form of the diaphragm is 51.4 MPa, while the fatigue stress at the weld toe around the longitudinal rib web and longitudinal rib bottom plate in the new perforating form is 5.1 MPa and 39.6 MPa respectively. It is showed that the fatigue stress of the new perforating form is smaller. Based on the fatigue failure criterion of crack propagation to 1/2 of the plate thickness, the fatigue life of the single hole form and the new perforating form of the diaphragms are 3.56 million and 18.33 million times, respectively, which explains that the new perforating form has significant advantages in fatigue performance.