Overview of NDT methods for mechanical cracks

ZHOU Zhi-xin

                                                  (No. 715 Research Institute of China Shipbuilding Industry Co., Hangzhou 310023, China)

Abstract: Aiming at the problem of mechanical crack propagation and testing, the commonly used crack nondestructive testing (NDT) methods were narrated, in detail, the current situation of the development of magnetic particle testing (MT) and penetration testing (PT) technology was introduced. The characteristics, action principle of several NDT methods emerged in recent years were detailed described, especially in the laser ultrasonic testing technology, electromagnetic acoustic testing technology(EMAT), ultrasonic infrared thermography testing technology, pulsed eddy current (PEC) and eddy current array (ECA) testing technology. The advantages opposite to the traditional testing technology were compared, and the future development trend of the new crack testing methods was prospected. The results indicate that, there will be developed from artificial to intelligent, automated and visualized, and the composite pattern testing will be more widely used in the new NDT methods. The development of testing instruments will take reducing energy consumption and improving the noise-signal ratio as the principal. The application of new crack NDT methods will be more professional in special fields of engineering.
Key words: nondestructive testing (NDT); present situation; emerging; trend