基于模态曲率法的大跨度斜拉桥损伤识别

大跨度斜拉桥是重要的交通结构,研究其在主梁损伤条件下的损伤定位问题具有重要的工程价值。合理选择设计参数并对其进行敏感性分析,根据现场实测的桥梁动力特性数据,通过调整选定的设计参数对初始的有限元模型进行修正。在基准有限元模型的基础上,通过模拟不同位置和不同程度的主梁损伤,探讨了模态曲率法对结构损伤识别的有效性。结果表明,模态曲率法能够对大跨斜拉桥进行初步的损伤定位,确定主梁单处损伤和多处损伤的损伤位置;对于单处损伤,在噪声水平3%的情况下仍具有较好的适用性。从而为后期更为精确的桥梁结构损伤检测提供依据。

Damage identification for long-span cable-stayed bridge based on modal curvature method

The cable-stayed bridge is a kind of important transportation structures.It is very meaningful to locate the damage caused by girder damage.Choosing the design parameters properly and doing the sensitivity analysis,the finite element model can be updated by using ambient vibration measurement results.Based on the updated mode1,by imitating different locations and different levels of girder damage,the modal curvature method is discussed for bridge damage identification.The results show that the modal curvature method is very effective for the initial damage detection of long-span cable-stayed bridges with single or multiple damage position.It still has usability of detecting single damage position with 3% noise level.It proposes a basis for more accurate structure detection in later period.