Dynamic Analysis of a 155-mm Cannon Breech

摘要

This report describes a finite element analysis of the breech closure for the 155-mm M199 cannon, which is normally mounted on the towed howitzer M198. This configuration has an excellent record for reliability in the field and is easy to service. However, when the breech is used in an ammunition test environment, some maintenance problems exist. Our analysis was for a nine-body problem with thirteen contact surfaces, and was solved for both static and dynamic load cases. The two dynamic loads were of similar shape with different loading times. The nine bodies in the model included a facility mount, four major structural components, the obturator seal, and three minor components. The results showed that the major components are normally subjected to quasi-static loading, but under fast 'pressure spike' loading, the dynamic effect can be important. This is particularly true for the contact between minor components that can show extreme behavior with the fast-loading rates.