The Influence of Different Constraints and Pretightening Force on Vibration and Stiffness in Railgun

The vibration characteristics and stiffness of the railgun launchers are of great importance to the system performance. The launcher with different constraints and pretightening force shows a different vibration characteristics and stiffness which may have a negative influence on the sliding mechanical contact, and may result in the decrease of the firing precision due to muzzle vibration. The 3-D finite-element modal and static analysis of the railgun in different constraints and pretightening force are calculated. Different constraints (including cantilever, simply supported, overhanging, discrete, and stationary) and the size of the pretightening force are discussed. In order to compare the natural frequency, corresponding vibration modals and the deflection of the self-weight condition, the advantages and disadvantages of these constraints and the size of pertightening force are investigated. According to the modal and static analysis, the constraints and pretightening force of the railgun launcher are analyzed, the change rule of their vibration characteristics and the stiffness are obtained, and some suggested measures are put forward.