油气、电力和航空航天等行业广泛使用金属结构件组成设施和设备，需对结构件实施在线高精度检测以及时发现缺陷，保障设施和设备的正常运转和生产安全。本项目研究复杂金属结构的柔性电磁超声相控阵成像检测方法，融合电磁超声非接触的优点和相控阵高精度成像检测的功能。本项目拟从基础研究的层面解决柔性电磁超声相控阵检测中的新问题，研究内容包括：电磁超声换能单元结构和精确建模；阵列柔性结构和单元定位方法；阵列相控、成像算法和阵列形变条件下的算法修正与补偿；电磁超声相控阵的实验装置研制和检测实验研究。项目主要涉及科学问题和关键技术难点包括铁磁材料电磁超声检测的磁致伸缩效应分析、解析与数值结合的换能单元声场表征、阵列形变的测量及形变数据在相控和成像算法中的融合，等等。本项目的顺利实施将大大提高复杂金属结构缺陷在线检测水平，支撑由其构建的设施和设备的完整性评估和维护，为确保多行业、多领域生产安全做出重要贡献。

Metal structures are used widely to build infrastructures and devices in many fields like oil & gas, electric power, aerospace etc. It’s required to conduct highly accurate online testing of the metal structures to find defects in time and ensure the normal operations of the infrastructures and the devices. In this project we propose studying imaging and testing of the complex metal structures with flexible electromagnetic ultrasonic phased array, combining the non-contact nature of electromagnetic ultrasound and the imaging capability of an ultrasonic phased array. In this project we aim to solve new problems in testing with flexible electromagnetic ultrasonic phased array from the aspect of fundamental research. The research content includes, the structure of the electromagnetic ultrasonic element and its accurate modeling, the flexible structure of the array and location of the elements, the phase control and imaging algorithms of the array and revision and compensation when the array undergoes shape change, the experimental device development and the testing experiments. The main scientific problems and key technical difficulties include the analysis of the magnetostriction effects when testing ferromagnetic materials, characterizing the acoustic field of the electromagnetic ultrasonic element with combined analytical and numerical methods, the measurement of the shape change of the array and the fusion of the shape changing data in the phase control and imaging algorithms, etc. The application of this project will improve the level of online testing of complex metal structures and support the integrity assessment and maintaining of the infrastructures and devices built from them, and make important contributions to the safety of many industries.