Research And Development Of Portable Stress Testing Equipment Based On DSP And Barkhausen

With the extensive use of ferromagnetic material, realizing the non-destructive stressmeasurement has got more practical value. In this paper, a set of non-destructive stress testingequipment is developed based on the Barkhausen effect detection principle for ferromagnetic materialand the digital signal processing function of DSP.Firstly, the Barkhausen noise mechanism of production and the relation between the Barkhausennoise and ferromagnetic material stress are discussed. Secondly, the hardware part of the portablestress testing equipment is designed and achieved, including the hardware selection, circuit design andhardware debug. The hardware part is made of DSP module, signal generating circuit, poweramplifier circuit, stress testing probe, signal conditioning circuit, acquisition circuit, serialcommunication circuit, ARM human-computer interaction module and power supply module. Then,the software design of the equipment is completed, including the generation of drive signal, thecollection and storage of MBN signal, FIR band-pass filtering and serial communication. The RMS,average value, ring number, peak value and peak width ratio of MBN signal are extracted as features.And the calibration of the five features and the equipment’s stress testing is achieved with the look-uptable interpolation method, the two functions and three functions method. Finally, the results of theportable stress testing equipment experiments prove that this equipment is feasible.