机械构件疲劳裂纹的激光超声检测新方法研究

机械构件疲劳裂纹检测方法对于提高机械装备安全运行，防止事故发生具有重要理论和现实意义。项目针对机械构件疲劳裂纹检测难题，利用激光超声技术无损、非接触、高分辨、可达性好等特点，提出一种机械构件疲劳裂纹激光超声检测新方法，攻克系列适应工业应用环境下机械构件裂纹激光超声检测的技术。项目的主要研究内容包括：研究基于热弹效应的的激光超声产生及超声波传播理论；研究机械构件疲劳裂纹萌生与扩展机理，建立机械构件疲劳裂纹扩展模型；研究激光超声信号时频特征与裂纹特征之间映射关系，建立机构构件激光超声信号模型；研究激光热弹的裂纹超声信号特征提取和参数识别技术；提出一种基于激光超声的机械构件疲劳裂纹检测方法；研制机械构件疲劳裂纹激光超声检测实验平台；形成一套基于激光超声的机械构件疲劳裂纹无损检测的理论、方法和技术体系。项目研究对促进机械构件疲劳裂纹无损检测的理论发展，保障机械系统的安全可靠运行具有重要理论意义。

The mechanical component fatigue crack detection is important for preventing accidents and improving the reliability of the using of mechanical equipment. Based on the non-destructive, non-contact, high-resolution laser ultrasonic technology, this project combined it with the development of modern signal processing and detection technology, carrying out laser ultrasonic-based mechanical component fatigue crack detection method.A set of non-destructive testing methods to adapt to the members of mechanical component in the industry environment will be developed. The main contents of the project include: To study the mechanism of laser ultrasonic theory;To study the mechanism of fatigue crack propagation and laser ultrasonic signal propagation mechanism; research in crack growth model and laser excitation the ultrasonic signal model; to study laser ultrasonic signal frequency mapping relationship between the characteristics and crack characteristics; to study laser thermoelastic crack detection, information extraction and signal processing methods; fatigue crack detection method proposed a laser-based ultrasonic mechanical component; mechanical component fatigue crack simulation detection experiment platform will be built; to form a set of laser-based ultrasonic nondestructive testing theory methods and technology system of mechanical component fatigue crack .Research projects on mechanical component fatigue crack destructive testing provide theoretical improvement and technological innovation, and improve the reliability of mechanical equipment. Its outcome has important theoretical and technical value, occupying a broad application prospects.