Computation of magnetic contact forces

It is well known that the conventional force methods have failed in calculating the contact forces when magnetic materials are touching each other. This paper presents a general scheme for computation of contact forces without any thin air-gap insertion between the materials. Maxwell stress tensor method, one of the most popular methods, is adopted by using the virtual air-gap scheme. By using the scheme, general contact situations such as iron versus iron, iron versus magnet, magnet versus magnet, irregular shaped objects, and high field saturation can be resolved in a consistent way. The proposed scheme is easily applicable by just implementing in the post-processing step. For validation, a simple electromagnet system was devised and fabricated for comparison of numerical calculations and experimental measurements.