田颖

摘 要：界面粘接强度的降低是目前广泛应用于建筑领域的隐框支玻璃幕墙破坏的主要原因。针对隐框支玻璃幕墙，提出了一种非线性超声兰姆波检测方法。通过理论和实验研究，验证了该方法的可行性。首先，利用压电陶瓷换能器产生汉宁窗调制的激励信号。采用人工热老化的方法加速界面结合强度的退化，得到不同老化周期的反射信号。然后，分别采用离散傅立叶变换（DFT）和小波包分解两种方法进行特征提取，并采用归一化和回归分析对两种方法进行比较。实验结果表明，采用二阶相对非线性系数的振幅积分法能灵敏地反映界面结合强度，而三阶相对非线性系数的变化曲线不明显。小波包能量法的计算结果与振幅积分法接近，与实际情况相符。二阶相对非线性系数先在小范围内波动，然后下降，最后随着热老化时间的延长而增大。但小波能量法的均方误差较小。小波包能量法具有更高的精度，对趋势的描述具有更高的允许误差能力。

关键词：隐框支玻璃幕墙;结构硅酮密封胶;界面粘接强度;非线性超声兰姆波;小波包分解

中图分类号：TQ437+.6;TU58                    文献标识码：A                文章编号：1001-5922（2021）04-0106-05

Abstract：The main reason for the failure of the glass curtain wall with concealed frame support， which is widely used in the field of architecture， is the decrease of the bonding strength of the interface. A non-linear ultrasonic Lamb wave detection method is proposed for glass curtain wall with concealed frame. The feasibility of this method is verified by theoretical and experimental research. Firstly， the excitation signal modulated by Hanning window is generated by piezoelectric ceramic transducer. The method of artificial thermal aging is used to accelerate the degradation of interface bonding strength， and the reflection signals of different aging periods are obtained. Then， Discrete Fourier Transform （DFT） and wavelet packet decomposition are used for feature extraction， and normalization and regression analysis are used to compare the two methods. The experimental results show that the amplitude integral method with the second-order relative nonlinear coefficient can sensitively reflect the interface bonding strength， while the change curve of the third-order relative nonlinear coefficient is not obvious. The result of wavelet packet energy method is close to that of amplitude integral method， which is consistent with the actual situation. The second-order relative nonlinear coefficient first fluctuates in a small range， then decreases， and finally increases with the increase of thermal aging time. But the mean square error of wavelet energy method is small. Wavelet packet energy method has a higher accuracy and a higher tolerance for trend description.

Key words：concealed frame supported glass curtain wall; structural silicone sealant; interface bond strength; nonlinear ultrasonic Lamb wave; wavelet packet decomposition

0 引言

玻璃幕墻作为一种外围护和装饰结构，以其灵巧、轻盈、透明、结构美观等优点在建筑领域得到了广泛的应用。玻璃幕墙主要由玻璃板和胶粘接构组成。玻璃幕墙分为框架式、半露式和隐式框架支撑玻璃幕墙。隐藏式框架支撑玻璃幕墙由于其整体美观而更受欢迎，因为它将金属框架隐藏在玻璃背面。……