基于高频动态响应的点阵夹芯结构损伤识别研究

Research on damage identification of lattice sandwich structurebased on high frequency dynamic response

针对点阵夹芯结构的脱焊损伤,提出了一种基于高频激励下结构ODS(operational deflection shapes)的损伤检测方法。ODS包含结构的整体动态响应特性,尤其是高频激励下损伤区域的局部振动信息。首先通过仿真计算出损伤局部区域的特征频率,选取合适的高频宽频带激励损伤结构。然后,采用压电片与扫描式激光测振仪结合,检测高频稳态信号激励下损伤结构的动态响应,综合考虑频段内多个频率下的ODS,由损伤成像中共振峰的位置,直接定位损伤。仿真与试验均验证了该方法识别损伤的有效性。

The operational deflection shapes(ODS)under high frequency dynamic response analysis method was proposed to detect the debonding welding defects in lattice sandwich structure.The ODS contains the overall dynamic response characteristics of the structure,especially the local vibration information of the damaged area under high-frequency excitation.First,the characteristic frequency of the damaged local area is calculated by simulation,and the appropriate high-frequency and wide-band excitation damage structure is selected.Then,the PZT is combined with a scanning laser vibrometer to detect the dynamic response of the damaged structure under high-frequency steady-state signal excitation,and comprehensively consider the ODS at multiple frequencies in the frequency band to directly locate the damage.Both simulation and experiment verify the effectiveness of the method in identifying damage.