Abstract:

Some automatic weapon breechblock formed 1mm depth crack after firing of 523 rounds during the finalized test. In order to estimate whether the residual life satisfies the requirements for the use of the breechblock, the crack formation and propagation life has been studied using analytical and numerical method. Considering the effect of the roughness level, the fatigue life is no less than 1 650 rounds under the conditions of normal temperature and standard charge. It is greater than the design target. Based on the simulation result, we analyzed the influence factors of the breechblock fatigue crack formation life and took the measures to reduce the breechblock roughness level. The breechblock fatigue life has been en- hanced to more than 1 800 rounds.

Key words: ordnance science and technology, breechblock, fatigue crack, the produce life of fatigue crack, the growth life of fatigue crack