Force and torque computations with hybrid methods

Alternative methods are presented for computing the magnetic forces and torques associated with hybrid solutions of magnetostatic or eddy current problems. The challenge is to retrieve the forces not just accurately but also with as little extra work as possible. The authors analyze several methods and the errors inherent in them. The analysis shows that the equivalent currents method is the best approach for computing forces with hybrid solutions. Force values obtained with test problems by using the proposed methods, including the coupling of the computed forces to the equations of motion, are compared to analytical and measured results