Ultrasonic Feature Imaging Method Of Friction Stir Welding Seam Of Aircraft Fuel Tank

Aircraft fuel tank is the source of the aircraft system,Its main task is to store fuel and provide fuel to the engine,ensure the stability of the engine during the flight.At present,friction stir welding technology is mainly used in aircraft fuel tank skin welding,This technology has many advantages such as high efficiency 、 low consumption、small deformation、no pollution and so on, which is widely used in the field of sheet welding technology.In the welding process of aircraft fuel tank skin,due to the selection of welding process parameters and the influence of environmental factors,there will be some flaws in the welds as close to the surface 、 fine and orientation complex,which may cause safety hidden danger of shedding and oil leakage between base metal,bring great loss to national property.Nondestructive testing is one of effective means of quality assessment that can help enterprises to filter out the qualified aircraft fuel tank and further improve the safety and reliability of aircraft fuel tanks in the use of the process.In order to detect the common defects in the weld of aircraft fuel tank.Based on the traditional manual ultrasonic inspection of the aircraft fuel tank weld and combined with automatic detection technology,it developed an automatic ultrasonic feature scan imaging system which adopted Multi- probe and multi- angle.Ultrasound system is made for the multi channel full wave detection is made for signal analysis and processing,Ultrasonic feature imaging with the echo amplitude and phase information of the defect signal as the characteristic parameter to show the position and size of the defects in the form of the visual image.Through the design of high precision mechanical and electrical control system.To ensure the accuracy of mechanical transmission which is better than 0.2mm.The system is suitable for the discovery defects of close to the surface 、fine and Orientation complex.For defects of fine and Orientation complex,the system can detect the defects in the distance 0.1mm on the surface of the weld.For defects of close to the surface,the system can detect the longitudinal defect of the wall thickness of 0.3mm; In the experiment, we combine detection of transverse wave and longitudinal wave to improve the detection sensitivity and resolution greatly for eliminate the defects of missing and false.we can callback history of detection record after the completion of the testing to review the testing date again.The paper mainly introduced the principle, feature and method of ultrasonic feature scan method of aircraft fuel tank’s weld.According to the oil tank weld inspection requirements to design of the corresponding probe group support and mechanical and electrical control system,Complete automatic detection and control of Aircraft fuel tank weld. Making standard samples with artificial defects aims to test experiment and get feature image for proved the capability and detection accuracy of the system.