A rail vibration test and analysis method for the electromagnetic launching process

• Proposed a monitoring system of small transient vibration in electromagnetic field.
• Fiber-optic displacement sensors were used to acquire vibration data.
• Performed a modal analysis of rail’s vibration and dynamic responses.
• Analyzed natural frequencies of the electromagnetic launch system.

During the electromagnetic launching (EML) process, rail vibrations occur due to the electromagnetic force generated by an acute current. These vibrations result in a reduced launch velocity and decreased launch efficiency. To measure the vibration amplitude of a rail accurately and to analyze the internal relationships between current strength, rail material and vibrations, a small transient vibration in a strong electromagnetic field was studied in this paper. Related experiments were also performed on the test system. Fiber-optic displacement sensors were used to collect vibration data at key locations along the rail. Using virtual instrument technology, a software platform was designed that displayed the vibration waveform and analyzed the time, frequency domain and other parameters. We collected data on the vibration response and the modal parameters of the rail and determined the natural frequencies of the electromagnetic launch system by performing a modal analysis of its vibrations and dynamic responses that combined experimental and theoretical methods. Methods of optimizing the structure’s vibration and dynamic response and of assessing the damage to it could be studied further on the basis of the results described in this paper.