Acceptance Testing Welded Ammunition Belt Links Using Acoustic Emission

The objective of the work described in this paper was to provide a reliable method for 100 percent acceptance testing resistance welds used in the fabrication of 40-mm automatic weapon ammunition belt links. Links containrounds of ammunition and are coupled together to form a belt which is automatically fed into the weapon. If one of the links in a belt fails, the immediate result is a jammed weapon. Four projection resistance welds (two on each side) are used to assemble the link, and weld quality can vary widely. Conventional nondestructive test techniques cannot distinguish a sound resistance weld from a weak one in the post-weld condition. This work has shown, however, that by applying a moderate proof load to the weld joint, weak welds can be detected by acoustic emission. The technique is being adapted to production application with an expected inspection rate of 1200 links per hour in its initial version. This work is representative of many applications of acoustic emission to measure component structural integrity that can be accomplished within existing state-of-the-art technology.