Two-Dimensional Gapped Smoothing Method for Impact Damage Detection of Composite Laminates
复合材料板冲击损伤检测的二维间隔平滑法

A new damage detection method is proposed in this paper based on vibration date of composite laminates. The original 1-D gapped smoothing method (GSM) is updated by 2-D GSM, and the standardized damage index for 2-D GSM is also presented. Comparing the proposed method with most other damage detection methods which are also based on the vibration data, this method needs only the test data of structure containing defects to determine the presence of defects and accurately locate them without requirement of baseline signal of an intact structure as contrast signal. Aiming at the spall damage due to impact in quasi-isotropic carbon fiber-reinforced composite laminate board, piezoelectric chip array combined excitation was adopted, and the multi-frequency simultaneous excitation of torsional vibration type was obtained. Then, fast and efficient damage detection is realized. Structural response ODS (operational deflection shapes) at different fixed frequencies was measured by scanning laser vibrometer (SLV) system, the damage index was obtained based on proposed 2-D GSM. Experimental results show that the impact damage in quasi-isotropic carbon fiber-reinforced composite laminate board may be correctly detected by 2-D gapped smoothing method with rather good accuracy.