Simulation and Extension of the Firing Pin Fatigue Life of a Mortar Howitzer
Most of the firing pins feature slender and variable cross-section structures.Under the ac-tion of cyclic impact force,it is easy to cause structural stress concentration and alternating stress,and fatigue fracture failure often occurs,which seriously affects the reliability of automatic weapons,and e-ven threatens the safety of combatants.A mortar howitzer occasionally saw its firing pin fracture in the test.The fatigue life of the firing pin is about 200 rounds.In order to improve the fatigue life of the mortar howitzer firing pin,a transient impact model is established for the pin moving against the limit block at high speed under the action of the backward force generated by gunpowder gas based on the load transfer process.The alternating stress of the pin during the impact process is obtained.Through the fatigue life evaluation of the pin under cyclic load,it is found that the calculated fatigue life of the pin is basically consistent with test phenomena.The accuracy of the calculation model is verified.On this basis,a study on the improvement of the fatigue life of different materials is carried out.The study shows that the fatigue life of the firing pins is increased from 215 rounds to 1 670 rounds after the mate-rial was changed from PCrNi3Mo to 30CrNi2MoVE,and the improvement effect is significant.The im-proved firing pin has not broken in its life cycle after being verified by live fire tests.
mortar howitzerlaunch processload transfertransient impactcyclic loadfatigue life
万方数据
维普
