Delamination failure analysis of G10 insulator in electromagnetic rail launcher

Abstract The electromagnetic (EM) rail launcher G10 insulator is prone to delamination damage during launch, which affects the service life of the insulator. Through the secondary development of ABAQUS® commercial finite‐element software, an EM‐structure coupling launch dynamics model considering projectile‐barrel coupling is established. The simulation indicates that the transverse swing of the projectile changes in a sine‐like law, and the time of the upper half wave corresponds to the pulse width of the impact force pulse waveform. The stress concentration occurs on the inner surface of the insulator where the contact‐impact occurs, resulting in impact damage. The midline of the insulator inner surface bears a large compressive strain under the action of pre‐tightening force, and the insulator is compressed oscillatingly under the influence of the time‐varying load of the rail during launch. Under the condition of repeated launch, the launch package repeatedly impacts the insulator, and the alternating load of the rail is cyclically loaded on the insulator with impact damage, which will cause the compression fatigue of the insulator and the expansion of impact damage crack. They are the main reasons for the delamination failure of insulator, and the experimental analysis is carried out. This study provides a method to study the delamination failure mechanism of the insulator, and provides guidance for improving the life of the insulator.