预应力混凝土组合箱梁损伤与承载力分析

为了研究结构承载力与损伤程度之间的关系,以五跨预应力混凝土组合箱梁为例,以不同部位抗弯刚度的折减来模拟不同程度的损伤,运用模态应变能法和柔度差法对结构进行了损伤诊断.在此基础上,研究了密集交通和一般交通状态,结构的损伤程度与结构承载力之间的关系.研究结果表明:对于连续组合箱梁结构,柔度差法比模态应变能法的识别效果更好;在任意交通状态,且结构损伤位置以及损伤程度相同的情况下,结构可靠度指标和承载力系数能够同时表明结构是否满足使用要求.

Analysis of the damage and loading capacity of prestressed concrete-composited box girders

In order to study the relationship between the damage degree and the loading capacity,several damage conditions were simulated for a reduced scale model of a prestressed concrete-composite box girder.with fivespan each damage was simulated by reducing the flexure stiffness in several parts of the model.The modal strain energy and the flexibility method were used for damage detection.The relationship between the damage degree and the loading capacity was studied on the different traffic condition.The results showed that the flexibility method is more sensitive than the modal strain energy method to the continuous composite box beam structure and can exactly locate the structure damage location and degree.The reliability index and loading rating factor are able to consistently demonstrate the actual service state of the structure under the same damage position and degree.