一种考虑微观结构的磁声发射理论模型

Theoretical model of magnetoacoustic emission considering the microstructure

磁声发射是评价铁磁性材料力学性能的一种重要无损检测方法,然而鲜见磁声发射理论/数值模型的报道。本文提出了一种考虑微观结构(位错密度、晶粒尺寸)的磁声发射理论模型。通过数值计算,研究了磁化结构参数和微观结构参数对磁声发射信号包络的影响。之后,重点对磁声发射理论模型的合理性进行了验证。基于不同硬度试件上测得的磁声发射信号,利用遗传算法对理论模型中的动态磁滞参数和磁化结构参数进行了反演。结果发现,在反演参数下理论模型计算得到的磁声发射信号与实验信号吻合较好,且关键磁滞参数的反演值与理论值最大误差小于15%。因此,提出的理论模型可用于磁声发射信号的预测。

Magnetic acoustic emission(MAE)is an important non-destructive testing method commonly used to evaluate the mechanical properties of ferromagnetic materials.However,there are few reports on the theory or numerical models of MAE.A theoretical MAE model considering the microstructure(dislocation density and grain size)is proposed in this paper.The influences of magnetization parameters and microstructure parameters on the envelope of MAE signal are analyzed through numerical calculations.After that,the rationality of the MAE model is validated.Based on the MAE predicted signals with different hardness specimens,the dynamic hysteresis parameters and magnetized structural parameters in the theoretical model were inverted with the genetic algorithm.The results demonstrate that the MAE signals calculated from the theoretical model under the inversion parameters are in good agreement with the experimental signals,and the maximum error between the inversion values of the key hysteresis parameters and the theoretical calculation results is less than 15%.Therefore,the theoretical model can be used to predict the MAE signals.