基于结构动态响应统计特征的损伤指标研究

Damage index based on statistical properties of structural dynamic responses

为了提高土木工程结构损伤识别的可靠性和有效性,本文提出一种基于结构动态响应统计特征的损伤指标,并对其可行性进行研究。文中首先在结构随机振动理论基础上推导出结构动态响应(包括位移、速度和加速度)的统计特征(包括均值和方差)与结构损伤位置和损伤程度之间的关系;然后通过敏感性分析确定以结构位移的方差作为结构损伤识别的损伤指标;最后,数值模拟一六层钢筋混凝土框架结构在白噪声激励下的动态响应,观察在不同损伤位置和损伤程度下结构动态位移方差的变化,从而对选择结构位移的方差作为损伤指标的可行性进行评估。研究得出结论,使用结构动态响应的统计特征作为土木工程结构损伤识别的损伤指标是可行的。

For improving the reliability and efficiency of damage identification for civil engineering structures, a novel damage index based on statistical properties of structural dynamic responses is proposed in this paper. Based on the theory of structural random vibration, the relationship between statistical properties, including the mean and vafiance of the structural dynamic responses, including displacement, velocity and acceleration, and structural damage location and level is obtained. Through sensitivity analysis, the variance of structural dynamic displacement is selected as a damage index for structural damage identification. The dynamic response of a six-floor RC frame is numerically simulated under the excitation of white noise. The feasibility of the proposed damage index is evaluated by investigating the change of the variance of structural dynamic displacement in the case of different damage locations and levels. A conclusion is drawn that it is feasible to use the statistical properties of the structural dynamic responses as the damage index in the damage identification for the civil engineering structures