Abstract:
The present invention relates to a safety inspection method for a structure using a nonlinear ultrasonic modulation method. The safety inspection method comprises a step of vibrating a structure by applying both signals with each different frequency to the structure; a step of converting the response of the structure generated by the vibration to digital signals; a step of extracting primary modulation signals by removing and synchronous-demodulating the harmonic and linear responses of the frequency signals from the digital signals; a step of generating a first sideband spectrogram by extracting the primary modulation signals by continuously changing the frequency of the signals with each different frequency and coupling the primary modulation signals; and a step of discriminating whether or not the structure has cracks from the first sideband spectrogram. The present invention can precisely discriminate the existence of damage even if having the lower voltage level of ultrasonic waves than the existing technology; thereby reducing the power consumption of a sensor.
Abstract:
본 발명은 손상과 초음파 진행 사이의 상호 작용을 시각화해 손상의 위치와 크기 등에 대한 정보를 현장 실무자들도 쉽고 직관적으로 확인할 수 있도록 함으로써 효율적인 터빈 블레이드와 같은 회전 구조물 관리를 위한 건전성 평가 시스템에 관한 것으로서, 회전 구조물의 일측에 펄스 레이저를 조사하여 초음파를 발생시키는 초음파 생성시스템, 상기 펄스 레이저의 조사 시기를 조정하는 펄스 레이저 제어시스템, 상기 회전 구조물의 타측으로부터 발생된 초음파를 측정하는 초음파 계측시스템 및 계측된 초음파 신호를 영상화하고 상기 회전 구조물의 손상 유무, 손상 위치 및 심각도 정보를 자동으로 제공하는 손상 감지시스템을 포함한다.
Abstract:
The present invention relates to an effective integrity evaluation system for a rotating structure such as a turbine blade, and enables field users to intuitively confirm information on the location and size of a damaged portion by visualizing the interaction between the damaged portion and an ultrasonic wave. The apparatus for a laser ultrasonic imaging of a rotating structure includes: an ultrasonic wave generation system which irradiates one side of a rotating structure with a pulse laser, in order to generate an ultrasonic wave; a pulse laser control system which adjusts the irradiation time of the pulse laser; an ultrasonic wave measuring system which measures an ultrasonic wave generated on the other side of the rotating structure; and a damage sensor system which visualizes the measured ultrasonic wave and automatically provides information on the existence, location, and severity of damages. [Reference numerals] (11) Pulse laser; (21) Location confirmation; (22) Angle sensor; (30) Data collection; (41) Ultrasonic wave imaging; (42) Automatic detection of a damaged portion; (AA) Main computer; (BB) Image processing; (CC,EE) Control; (DD) Synchronization