Numerical Calculation of Contact Resistance of Electromagnetic Railgun

The armature-rail contact resistance is generally considered to reflect the contact state of the armature and the rail during the launch process of the electromagnetic railgun. However, due to the extremely short time of the armature acceleration process, it is difficult to directly measure the armature-rail contact resistance. In this paper, based on the simplified muzzle voltage model of the electromagnetic railgun, a numerical calculation method of contact resistance is proposed, which considers the armature body resistance and current skin effect, based on the experimental current, muzzle voltage waveform and combined with finite element simulation and MATLAB Program to perform calculations. Comparing the calculated results with the ratio of muzzle voltage to current (muzzle resistance), it is found that the value of the muzzle resistance is 2 to 3 times that of the calculated contact resistance.