频率测量模式在薄板分层损伤探测中的应用

Localization of Delamination in Plate Structures Using Natural Frequency Measurement

分层损伤是复合材料的主要破坏形式之一,该类损伤发展到一定程度时,不仅会导致结构承载力降低,更有可能因结构失效而引起灾难性破坏。针对此问题,基于固有频率易于测量、测量精度高的特点,将正交化后的固有频率变化量应用于含有分层损伤的复合材料薄板结构中,提出了一种新型反向确定结构损伤位置的理论方法。该方法应用于无损检测中,作为结构损伤定量检测的前期工作,在定量无损检测之前,可以一定范围内准确地预测分层损伤的位置,提高检测效率。利用该方法对复合材料薄板分层损伤位置进行了探测,并与试验结果进行了对比分析。结果表明,该方法具有较好的精确性,实施步骤简单、可靠,并具有一定的抗噪性。

Delamination is regarded as one of the most serious defect in composite materials,which reduces the structural capacity and will spread to cause a catastrophic collapse.Based on the simplicity and high accuracy of measurement for natural frequency,a new type of non-destructive measurement is proposed to determine the delamination location in composite plate structures by using normalized natural frequencies.The predicted location by this method can be used before applying the quantitative detection,which can be considered as a preliminary work to improve the detection efficiency.The validity of this method is demonstrated by comparing the predicted location of a delaminated plate modelling with experimental data.The results show the procedure simplicity and accuracy of this method.