Ultrasonic Self-focusing Linear Array Sound Field Analysis And Detection Application

Complex rotary components have a wide range of applications in electric power,aerospace,pipeline transportation and other fields,but forging processing of rotary components may produce internal defects,requiring fast and efficient detection means to ensure its reliability.Ultrasonic phased array detection technology can flexibly realize the deflection and focusing of the sound beam without moving or less moving the transducer.It is widely used in tube bar detection.There may be both circumferential and axial defects in the rotating member,but the conventional ultrasonic linear array transducer can only achieve electronic focusing in the short axis direction of the array element,and cannot achieve focusing in the long axis direction of the array element,so it is difficult to detect the circumferential direction at the same time.It needs to pass the special wedge or change the direction of the probe arrangement,to detect the longitudinal defects of the ring step by step,which is time-consuming and laborious,resulting in low production efficiency.In view of the above problems,this paper uses the self-focusing linear array transducer to build a self-focusing detection platform for complex rotating components to achieve rapid detection of complex rotating components.In terms of theoretical methods,the sound field calculation method and distribution characteristics of the self-focusing linear array transducer are studied.The non-paraxial approximation Gaussian sound beam superposition method is used to calculate the self-focusing linear array radiation sound field,in order to verify the effectiveness of the method.Accuracy and efficiency comparison with Rayleigh integral numerical method.On this basis,the theoretical method is used to compare and analyze the distribution characteristics of the focus intensity,focus size and focal length of the traditional linear array and the self-focusing linear array with the deflection angle.In practical engineering application,a self-focusing detection platform for complex rotary components is built.The detection platform is designed from both hardware and software to realize rapid detection of complex rotary components,and generate detection images in real time.Using the built-in detection platform,the self-focusing linear array transducer and the ordinary linear array transducer are used to actually detect the cylindrical workpiece with pre-buried defects.The results show that the self-focusing linear array transducer can simultaneously detect the circumferential direction and axial defects,while ordinary linear array transducers can only detect hoop defects,and the defect imaging signal-to-noise ratio of self-focusing linear array transducers is also superior to ordinary linear array transducers.