非晶丝端部磁场效应的模拟

实验表明,不同长度的非晶丝以及非晶丝端部不同的位置都具有不同的磁特性.为了研究这种端部磁场效应,基于磁荷分布的假设,采用数值计算方法获得了非晶丝端部的磁场分布.然后,基于数值计算结果,采用拟合方法获得非晶丝内部磁场分布的一般性计算形式.由于非晶丝内部磁场强度不可能超出外磁场强度,提出由中间的均匀磁区以及两端的入磁区和出磁区所构成的非晶丝三磁区模型,并由此获得端部磁场效应的临界长度计算公式.该理论模型对端部磁场效应的模拟计算结果与已有实验现象能够符合很好.

Simulation of magnetic end effect of amorphous wires

The existing experimental results have shown that the magnetic characteristics of amorphous wires with different lengths or of the same amorphous wire at different longitudinal locations are significantly different. To study this effect, the magnetic field at the end of the amorphous wires is obtained by numerical computation method based on the supposed uniform distribution of the magnetic charge. Then, the general formula of the magnetic field inside the amorphous wire is deduced by analyzing the calculation results and using the fitting algorithm. Because the magnetic field intensity inside the wire is restricted by the external magnetic field source, the model of three magnetic zones is proposed, which consists of the zone of uniform magnetic field in the middle of the wire, the magnetic field entrance-zone and exit-zone at the two ends. The critical length of the magnetic end effect can be estimated by a formula derived from the model. The simulation results of the magnetic end effect can satisfactorily explain the existing experiments.