【摘要】 研究目的:结构的疲劳细节对其疲劳破坏至关重要，为了分析钢底板波形腹板-混凝土组合箱梁的疲劳细节及疲劳寿命计算方法，为该类型结构的疲劳设计提供参考，制作缩尺试验梁模型，并对其进行疲劳试验，得到这种新型结构的疲劳破坏特征。结合模型试验，利用数值模拟和断裂力学分析方法，对新型组合箱梁的疲劳寿命计算及疲劳细节分类进行研究，并采用线性损伤理论对结果进行分析验证。研究结论:(1)钢底板波形腹板-混凝土组合箱梁在疲劳荷载作用下，其疲劳裂纹首先出现在底板与两侧腹板焊缝折角处，说明该处是新型组合箱梁重要的疲劳细节；(2)根据线性损伤理论，新型结构的疲劳细节分类总体上位于AASHTO规范疲劳类别的B类与C类之间，高于B′曲线下界值，低于B′曲线中值；(3)采用数值模拟和修正后的断裂力学方法得到的S-N曲线计算出的总损伤累积值误差分别为3%和6%,说明两种曲线均适用于新型钢混组合结构的疲劳寿命计算；(4)本研究成果可为钢底板波形腹板组合箱梁疲劳细节分类及疲劳设计提供参考或借鉴。更多还原

【Abstract】 Research purposes: The fatigue details of the structure are very important for its fatigue damage. In order to analyze the fatigue details and fatigue life calculation method of steel bottom plate corrugated web-concrete composite box girder, and to provide a reference for the fatigue design of the structure of the type, the scale test beam model was made, and the fatigue test was carried out, to obtain the fatigue damage characteristics of this new type of structure. Combined with model test, numerical simulation and fracture mechanics analysis were used to study the fatigue life calculation and fatigue detail classification of new composite box girder, and the results were analyzed and verified by linear damage theory.Research conclusions:(1) The fatigue cracks in the steel bottom plate corrugated web-concrete combined box girder under fatigue loading first appear at the weld fold between the bottom plate and the web on both sides, indicating that this is an important fatigue detail in the new combined box girder.(2) According to linear damage theory, the fatigue detail classification of the new structure is generally between categories B and C of the AASHTO Code fatigue category, which is higher than the lower boundary value of the B′ curve and lower than the median value of the B′ curve.(3) The error of total damage accumulation value calculated from the S-N curves obtained using numerical simulations and the modified fracture mechanics method is 3% and 6% respectively, indicating that both curves are applicable to the fatigue life calculation of new steel-concrete composite structures.(4) The research results can be used as a reference for the classification of fatigue details and fatigue design of combined box girders with steel bottom plates and corrugated webs.更多还原