Work

Wide and Narrow-Spectrum Laser Ultrasonics for Fatigue Crack Detection Using Nonlinear Modulation Analysis

Year: 2026

Type: article

Abstract: Laser ultrasonic technique is widely applied in non-destructive evaluation (NDE) and structural health monitoring (SHM) for the broadband generation of ultrasonic waves. However, controlling the spectral content of the laser-generated waves can enhance the sensitivity of damage detection. In this study, a finite element model is developed to investigate how laser beam diameter influences ultrasonic wave generation. A small beam diameter is used to produce a wide-spectrum (WS) response, while a larger beam generates a narrow-spectrum (NS) response. The two independent ultrasonic responses are then combined to form a dual-laser excitation approach. When a structure contains fatigue damage, nonlinear ultrasonic modulation occurs between the WS and NS responses, leading to the generation of sidebands. A spectral energy-based index is employed to quantify these sidebands and identify fatigue-induced nonlinearity. The results confirm that the proposed dual-laser ultrasonics method improves sensitivity to fatigue cracks compared to conventional single laser excitation.

Source: Journal of Sustainable Civil Engineering and Technology

DOI: 10.24191/jscet.v5i1.jscet_s_000036

Authors: Nazirah Ab Wahab, Chindada Sony

Institutions: Universiti Teknologi MARA System, Universiti Teknologi MARA, Czech Academy of Sciences, Institute of Thermomechanics

Language: English

Topic: Ultrasonics and Acoustic Wave Propagation

Subfield: Mechanics of Materials

Field: Engineering

Domain: Physical Sciences

Open Access status: bronze

OpenAlex ID: W7154770000

FWCI:

Cites:

Cited by:

Related to: