Phase-field-based study on the tensile fracture of ferromagnetic microwires

Ferromagnetic microwires, as a type of microscale magnetic fiber composite material, can be utilized for monitoring structural stress states. However, during actual service, overloading may lead to fracture damage, which can negatively impact their mechanical and magnetic properties, reducing the monitoring range. This study employs finite element analysis and fracture phase-field theory to simulate and model the tensile fracture process of ferromagnetic microwires, and the accuracy of the model is verified through experimental validation. Based on this, the relationship between crack depth and structural carrying capacity is analyzed. The results show that with an increase in crack depth, the maximum fracture stress decreases from 3.193 GPa at 0 μm to 0.9 GPa at 11 μm. The study also demonstrates that as the tensile stress on the ferromagnetic microwires increases and reaches the tensile strength, they exhibit a brittle material behavior, leading to rapid fracture. These findings provide a basis for understanding the failure of structural functions in the application of ferromagnetic microwires.