Research On Vibration Acoustic Modulation Method For Welding Phased Array Detection

As one of the most commonly used non-destructive testing methods,ultrasonic testing is based on the propagation characteristics of ultrasonic waves in the test piece,that is,using the various propagation characteristics of ultrasonic waves in the object to evaluate whether the test piece itself and its internal defects and defects.The phased array technology is a new ultrasonic non-destructive testing method,which can perform qualitative measurement of macroscopic defects well.It can realize beam focusing by adjusting the phase delay of transmitting and receiving signals of each array element in the array transducer.And beam deflection and other effects,forming a clear image with a high detection resolution.This paper first introduces the detection principle of phased array technology and some basic knowledge of ultrasonic,briefly introduces the sound field research of ultrasonic detection,and then combines the advantages of vibration sound modulation,consider combining phased array technology with vibration sound modulation to make it It can provide a certain research direction for the location of microcracks.Secondly,we carry out finite element simulation of vibration sound modulation.Through simulation,we confirm the feasibility of vibration sound modulation technology.We found in the simulation that the value of modulation factor can be used to judge the strength of modulation effect.The experimental parameters are optimized by simulation and theory.Finally,weld microcrack samples and microcrackless samples were prepared and tested separately.The results show that the contrast spectrum of the comparative test with or without microcracks is very obvious.By calculating the modulation factor,we can find that the value of the modulation factor without microcracks is almost zero.Then the contrast test of the position of the focus point of the micro-crack weld is carried out.Through experiments,we further found that the distance between the focus point and the microcrack and the modulation factor are in a negative correlation.The farther the phased array focus point is from the microcrack.The smaller the value of the modulation factor.From this we can obtain that compared with the phased arraydetection technology,it is feasible to use the phased array technology based on vibration sound modulation to locate the weld microcracks.