基于振动特性判别钢管混凝土两种材料间的脱粘规律

Discriminant analysis of conrete debonding of CFST based on nonlinear vibration characteristics

通过钢管混凝土推出试验,分析比较推出过程中各阶段钢管混凝土非线性振动特性的差异,研究影响钢管混凝土非线性特性的因素。利用解析模式分解提取钢管混凝土振动信号的第一阶振动分量,通过Hilbert变换得到频率振幅关系,分析钢管混凝土的非线性振动特性。3根钢管混凝土构件试验结果表明,构件非线性在整个加载过程中呈现出先增大后减小的变化趋势,钢管混凝土非线性振动特性受其界面作用影响。在未发生加载脱粘的情况下,混凝土浇筑质量不良将削弱其界面的胶结作用,从而降低非线性特性。

This paper firstly conducted push-out test and dynamic signal test on CFST.The difference of nonlinear vibration characteristics of CFST in different working conditions in push-out test was analyzed.And the influence factors of nonlinear characteristics of CFST were studied.The first order of vibration signal was extracted by utilizing analytical mode,the relationship of frequency-amplitude was obtained by Hilbert transform. The test results of three CFST members show that the nonlinear vibration characteristics first increase then decrease in all loading process,and the characteristics are affected by the interaction between steel tubular and concrete.The interface of cementation is weaken by the poor quality of concrete placement,thus the nonlinear characteristics is relatively low when the concrete debonding isn＇t occurred.