基于损伤敏感指标的斜拉桥结构损伤定位研究

研究斜拉桥结构的损伤位置识别问题。首先根据斜拉桥结构的受力特点,将其视为由斜拉索、主梁以及索塔组成的组合结构,对于斜拉索和主梁分别提出了广义模态应变能指标、位移灰关联指标以及索力变异指标等多种损伤敏感指标,并就观测噪声水平和损伤程度耦合影响下各损伤敏感指标的定位效果进行了系统研究。为提高存在观测噪声条件下损伤识别的可靠性和准确性,将证据理论引入损伤位置判别的决策过程,提出了基于多源损伤证据的损伤定位方法,实现了基于多源损伤信息的损伤定位。通过算例验证了所提出方法的有效性和优越性。

STUDY ON STRUCTURAL DAMAGELOCATION IDENTIFICATION BY DAMAGE INDICES FOR CABLE-STAYED BRIDGES

The damage location method by damage locating indices of cable-stayed bridge is presented. The cable-stayed bridge is regarded as a composite structure composed of cables, girders and the pylon on account of its mechanics properties. The generalized modal strain energy index, the displacement grey incidence and the cable tension index are presented for the damage location identification of cable-stayed bridges. The coupling impact of the measurement noise level and damage extent on identification results is systemically studied. Evidence theory is introduced into the damage locating procedure, and the damage location identification method based on multiple damage evidence is established. Then the damage location identification through multiple damage evidence is carried out by means of evidence theory. The feasibility and effectiveness of the proposed method are demonstrated by numerical examples.