Finite Element Analysis of a Brass 5.56mm Cartridge Case

摘要

The cartridge endures the load of very high pressure and heat generated from the fired-gas of powder when shooting. The intensity of the cartridge influences the performance of the weapon as well as the safety of user. One 5.56mm brass cartridge will snap after 6/7 times shootings in the test. Based on the theory of elastic-plastic mechanics, thermal-stress and contact mechanics, the high fidelity finite element model of the cartridge case and the gun wall is built, which is used to analyze the stress-strain field in the platform of the general FEA software ANSYS. The model is two-dimensional for the axial symmetrical characteristic, and we achieve the parameter model using the ANSYS Parameter Design Language. The resultant position of maximal stress is consistent with the test, and it oversteps the material yield limit, showing the model is high fidelity. The influence of initial gap is researched in detail, and the results indicate that the position of the maximal stress can be adjusted by controlling the initial gap. The data can be used in the modified design.