基于时序分析理论的钢管混凝土脱空缺陷检测方法研究

RESEARCH ON DETECTION METHOD OF GAP DEFECT OF CONCRETE FILLED STEEL TUBULAR BASED ON TIME SERIES ANALYSIS THEORY

将时间序列分析理论引入钢管混凝土脱空缺陷检测中,提出基于自回归模型(AR模型)和科氏距离(Cosh Distance,CD)的钢管混凝土脱空缺陷检测方法。采用AR模型分别对无损状态和带脱空状态下钢管混凝土构件的加速度响应信号进行拟合,获得无损状态和带脱空状态下的残差序列和方差。然后分别以科氏距离、欧氏距离(Euclidean Distance,ED)和马氏距离(Mahalalnobis Distance,MD)构造判别函数进行脱空区域识别。最后以数值模拟和带环形脱空缺陷的钢管混凝土构件动力试验来验证所提方法的可行性及可靠性。结果表明:欧氏距离和马氏距离在钢管混凝土脱空区域检测精度较差,甚至可能造成误判;科氏距离能够直观准确地检测出钢管混凝土环形脱空缺陷范围。

The theory of time series analysis was introduced into the gap defect detection of concrete filled steel tubular(CFST)members.A method based on AR model and Cosh Distance(CD)was proposed to detect the gap defect of CFST members.Firstly,AR model was used to fit the acceleration response signals of concrete filled steel tubular members in the non-destructive state and in the void state respectively,and the residual sequence and variance in the non-destructive state and in the void state were obtained.Secondly,the discriminant function was constructed by Cosh Distance,Euclidean Distance(ED)and Mahalalnobis Distance(MD)to identify the gap area.Finally,the feasibility and reliability of the proposed method were verified by numerical simulation and dynamic test of CFST members with circumferential gap.The results showed that the detection accuracy of ED and MD in the gap area of concrete filled steel tube was poor,and might even cause misjudgment.CD could directly and accurately detect the gap range of concrete filled steel tube with circumferential gap.