Research On Plastic Deformation Of Metal Materials Based On Acoustic Emission Characteristic Parameters

It is an important method in the field of research materials to study all aspects of materials from microcosmic and macroscopic.Traditional material mechanics measurement method can only achieve the basic mechanical properties,it is difficult to monitor the interior of the material.The elastic wave released by the acoustic emission source carries a large amount of information about the deformation process of the material,and the internal motion of the material can be tracked by analyzing the acoustic emission signal.In this paper,two kinds of metal materials(L360 and 35CrMo)commonly used in the petroleum industry were used to study the relationship between the mechanical properties and the acoustic emission parameters of the uni-axial stretching process.And experimental data of acoustic emission parameters of two kinds of materials were established.The relationship between the micro-plasticity change mechanism and the macroscopic mechanical response is constructed by using the time course of acoustic emission parameters combined with the stress curve.The advantages and disadvantages of each acoustic emission parameter in describing the material stretching process are analyzed.On the basis of this,the evolution law and characteristics of the acoustic emission parameters during the two materials were further summarized.Based on the variation rules and characteristics of the parameters,the stretching process is divided,which is consistent with the traditional stress and strain curve.The correlation analysis is carried out on the acoustic emission parameters of the two materials during the stretching process.And correlation between the acoustic parameters of the two materials is quantitatively analyzed by using the Pearson correlation coefficient and the Spearman rank correlation coefficient.Through the correlation analysis,the acoustic emission ringing count,the amplitude and the energy show a strong correlation throughout the stretching process.There are not many ways to quantitatively study the acoustic emission characteristics and mechanical properties.In this paper,through neural network and wavelet transform,characteristic parameters are used to obtain the curve with high coincidence degree with the stress time history.It provides some ideas for the quantitative analysis of acoustic emission parameters and material mechanics parameters.