Calculation of Armature Melting Wear Rate Based on Contact Surface Heat Distribution

Abstract

Wear between the armature and the rail directly affects the state of armature–rail contact, which in turn affects the service life and launching efficiency of the electromagnetic rail launcher. In order to investigate the armature melting wear law during the launching process, a heat distribution model on the contact surface of the armature–rail is proposed, and a transient calculation model of armature wear is derived; to solve the model, the excitation current, inductance gradient, and contact resistance of the launcher were calculated and further analyzed with respect to the kinematic characteristics of the armature chamber. On this basis, the change rule of armature melting wear rate and the influencing factors are studied, and the derived calculation model is verified by using the experimental method. The results of this study show that the trend of armature wear rate can be broadly classified into a rapidly increasing phase, a sharply decreasing phase, and a smooth phase, with the maximum wear rate reaching about 0.008; the coefficient of friction, rail material, and rail structure all have an effect on the magnitude of the armature wear rate, but do not affect the trend of the armature wear rate; the experimentally verified armature wear volume differs from the theoretically calculated wear volume by only 3.65%. The model and analysis results established in this article are of great significance for optimizing the armature structure, improving the armature–rail contact performance, and ensuring the launching safety.