Based on Barkhausen noise stress detection system
|School||Nanjing University of Aeronautics and Astronautics|
|Course||Measuring Technology and Instruments|
|Keywords||Barkhausen noise Stress Ferromagnetic materials Feature Extraction Digital Signal Processing Metal Magnetic Memory|
Fatigue stress concentration leading to failure and damage to the main reason. However, for metal equipment and components in service early damage, difficult to implement effective evaluation . With the feature extraction and information fusion technology development , as early as 1919, it was discovered that Barkhausen noise (Magnetic Barkhausen Noise, MBN) detection technology has been in the field of non-destructive testing of new applications , it can be ferromagnetic material components stress and residual stress, thereby detecting the microstructure of ferromagnetic material and the fatigue failure life assessment for effective diagnosis. First , review the status of non-destructive testing technology research , focusing on account of Barkhausen noise detection technology and Metal Magnetic Memory Testing Technology Research . This paper studies the MBN MBN signal generation and signal the main influencing factors , such as stress , hardness, plus incentives including excitation voltage and excitation frequency. Secondly , the completion of the Barkhausen noise stress detection based platform design . According MBN signal characteristics , is completed based on FEM Comsol excitation circuit design , high sensitivity detection coil to achieve MBN signal detection sensor. Again, the proposed values ??based on various characteristics such as MBN MBN signal envelope signal , number of rings , and other characteristics of the rms signal feature extraction methods, and with the metal magnetic memory testing methods were compared and proposed based on metal magnetic memory and the composite magnetic Barkhausen noise measurement system for stress testing of ferromagnetic materials . Finally, after the MBN DSP5509 embedded hardware -based detection system structures, including external expansion A / D conversion circuit , a memory circuit , USB data communication circuit to achieve a ferromagnetic material stresses on line.