搭接梁螺栓联接结构的状态识别

Condition identification for bolted joints of lap beams

利用频谱分析和小波包分析技术,针对敲击状态下搭接梁螺栓联接结构的加速度信号进行分析,根据不同预紧状态下响应信号的固有频率和优势频带的小波包能量变化,实现对联接结构的状态识别。分析结果发现,螺栓连接状态的变化与固有频率和优势频带的能量密切相关,在敲击下,预紧力越小,搭接梁的奇数阶固有频率越小,优势频带的能量也越大,表示其结构阻尼越大,联接结构的能量耗散增大,系统非线性增强。

Wavelet packet analysis and spectrum analysis are used to analyze the acceleration signals of bolted-joint structure in lap beams under peening excitation. According to the changes of the nature frequency and the energy distribution at ascendant frequency bands under different preloadings, it is achieved the condition identification of the bolted joints. The results of the analysis show that the looseness of the bolted-joint structure has a tremendous influence on the inherent frequency and the energy distribution at ascendant frequency bands. In the peening vibration environments, the smaller the preloading, the smaller odd-order natural frequency of lap beam, and the higher the energy at ascendant frequency bands. This phenomenon signifies that the greater the structural damping, the more energy dissipation and nonlinear characteristics increase.