Damage assessment in composite laminates via broadband Lamb wave

Fei Gao; Liang Zeng; Jing Lin; Yongsheng Shao

doi:10.1016/j.ultras.2018.01.005

Damage assessment in composite laminates via broadband Lamb wave

Ultrasonics. 2018 May:86:49-58. doi: 10.1016/j.ultras.2018.01.005. Epub 2018 Jan 11.

Authors

Fei Gao¹, Liang Zeng², Jing Lin³, Yongsheng Shao⁴

Affiliations

¹ Shaanxi Key Laboratory of Mechanical Product Quality Assurance and Diagnostics, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China. Electronic address: gf.4992328@stu.xjtu.edu.cn.
² Shaanxi Key Laboratory of Mechanical Product Quality Assurance and Diagnostics, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China. Electronic address: liangzeng@mail.xjtu.edu.cn.
³ State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Shaanxi Province, China. Electronic address: jinglin@mail.xjtu.edu.cn.
⁴ Shaanxi Key Laboratory of Mechanical Product Quality Assurance and Diagnostics, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China. Electronic address: birdshao@stu.xjtu.edu.cn.

PMID: 29361331
DOI: 10.1016/j.ultras.2018.01.005

Abstract

Time of flight (ToF) based method for damage detection using Lamb waves is widely used. However, due to the energy dissipation of Lamb waves and the non-ignorable size of damage in composite structure, the performance of damage detection is restricted. The objective of this research is to establish an improved method to locate and assess damages in composite structure. To choose appropriate excitation parameters, the propagation characters of Lamb waves in quasi-isotropic composite laminates are firstly studied and the broadband excitation is designed. Subsequently, the pulse compression technique is adopted for energy concentration and high-accuracy distance estimation. On this basis, the gravity center of intersections of path loci is employed for damage localization and the convex envelop of identified damage edge points is taken for damage contour estimation. As a result, both damage location and size can be evaluated, thereby providing the information for quantitative damage detection. The experiment consisting of five different sizes of damage is carried for method verification and the identified results show the efficiency of the proposed method.

Keywords: Composite laminates; Damage localization; Lamb wave; Pulse compression; Size evaluation.