航空发动机复合材料风扇叶片分层损伤超声相控阵识别方法研究

With the aero-engine fan blades develop into larger scale, lighter weight and higher performance, composite-material fan blades become the priority. Because the delamination is the most uneasily noticed and dangerous damage, the ultrasonic phase array, an effective delamination identification method, has attracted great attention. This project firstly studies propagation mechanism of ultrasonic wave in the delaminated composite material with wavelet finite element method; and analyzes relationship between factors like geometrical dimension, position, fiber distribution, angles, interface strength etc. and composite material reflection and refraction coefficients, in order to clarify the influence on propagation velocity and energy attenuation rate of ultrasonic wave. Secondly, the quantitative relation between the above factors and the characteristic parameter is established, so the quantitative rule of the delamination identification with the ultrasonic phase array is revealed. In addition, with the adaptive sparse dictionary for the decomposition and reconstruction of the ultrasonic phase array echo signal taken into consideration, the denoising and feature extraction are completed, thus the delamination is identified accurately. Finally, engineering validation and application research on the aero-engine fan blades is accomplished.This study can bring the innovation and breakthrough to basic principles, quantitative rules and denoising and feature extraction of the delamination identification with the ultrasonic phase array, which owes crucial theoretical significance and widespread application value.

复合材料风扇叶片是航空发动机风扇叶片大型化、轻量化及高性能化发展的首要选择，分层损伤是其隐蔽性最强且危害性最大的损伤形式，超声相控阵识别方法作为分层损伤的有效识别方法受到极大关注。本项目拟通过小波有限元方法研究含分层损伤复合材料的超声波传播机理；分析分层损伤几何尺寸及位置、纤维分布及角度和界面强度等因素与复合材料反射系数和折射系数的关系，阐明其对超声波传播速度和能量衰减率的影响；建立上述因素与分层损伤表征参数之间的定量关系，揭示分层损伤超声相控阵识别的定量规律，提出基于自适应稀疏字典的分解与重构方法，完成超声波回波信号的降噪和特征提取，实现分层损伤的精确识别。针对航空发动机复合材料风扇叶片开展工程验证与应用研究。通过本项目的研究，可望在分层损伤超声相控阵识别的基本原理、定量规律和回波信号的降噪和特征提取方面有所创新和突破，具有重要的理论意义和广泛的应用价值。

复合材料风扇叶片是航空发动机风扇叶片大型化、轻量化及高性能化发展的首要选择，分层损伤是其隐蔽性最强且危害性最大的损伤形式，超声相控阵识别方法作为分层损伤的有效识别方法受到极大关注。本项目首先使用区间B样条小波有限元法研究了复合材料层合板结构导波传播机理，然后使用多种基于稀疏理论的方式识别了复合材料结构分层损伤。项目共支持发表科技论文11篇，其中SCI论文9篇，EI论文2篇；申请专利6项，编写专著1本，获得科技奖励1项。项目研发成果有望用于航空发动机风扇叶片的健康监测，具有很好的国防应用前景。