An Automatic Mechanical Off Heavy Dynamic Stress Analysis

Combined with the 10th five -year key advanced research project of national defense "Firing technology for rifles with variable-firing-rate and double cyclic systems", the impacting dynamic stresses of this kind of rifle's three key elements(breech mechanism, receiver, firing pin) are analysed and studied in this paper. The distribution and magnitude of dynamic stresses of the breech mechanism, the receiver and the firing pin have been obtained with ANSYS/LS-DYNA when they are impacted. The rules of the distribution and magnitude of dynamic stresses of the breech mechanism in three different situations have been studied. The intensity of the breech mechanism has been checked. The main reason causing the breakage of the breech mechanism has been disclosed with analysing the distribution and magnitude of the dynamic stresses in two different situations. This provides useful references for mechanism design. The rules of the propagating behavior of stress wave and the phenomena of stress concentration have been analysed. The crack rules of the firing pin have been studied and corresponding improvement methods have been proposed. The service life of the firing pin is also predicted.The obtained results in this paper are of significant importance for shortening the period of developing weapon, decreasing development cost, enhancing designing quality of automatic weapons.