大跨度钢桁桥模型的精细化损伤定位模拟和试验研究

在役大跨钢桁桥数日众多，其杆件往往较长，所以识别出损伤杆并找出局部损伤所处位置对安全评定和加固尤为重要。针对这一问题，参考我国在役钢桁梁桥，基于健康监测的试验目的和相似理论设计制作了贝雷梁式筒支钢桁桥Benchmark模型。根据其结构形式、具体尺寸，并经试验结果修正，建立了基准Matlab有限元模型。环境激励下，首先隔...

Experimental and numerical studies on precise damage localization of a long-span steel truss bridge model

Large numbers of long-span steel truss bridges with long bars are in service. Therefore, it is imperative for their safety assessment and maintenance to obtain damaged bars and the location of local damage. To solve this problem, a simply supported bailey steel truss bridge Benchmark model for health monitoring was designed and constructed according to the highway and railway bi-purpose steel truss bridges employed in China. Based on structure form and detailed dimensions, a Matlab finite element model was established as the reference model due to the perfect match of the modal parameters with experimental results. Under ambient excitation, a triangular substructure was separated as a research object. Firstly, based on the Stochastic Damage Locating Vector (SDLV) method, the damaged bar was detected and additional sensors were installed on it to identify the local damage. Secondly, conventional SDLV method needs information from all nodes in a truss structure or a substructure of it, which results in high cost. Possibility of damage localization based on data from partial nodes in a substructure was discussed preliminarily. Both the numerical and experimental results indicate that the SDLV method can not only identify the damaged bars but also precisely locate the local damage; moreover, which lays a good foundation for damage detection based on the SDLV method using partial nodes.