Analysis And Study On Launch Dynamics Of A 120mm Mortar

In this paper, we study the launch dynamics of 120mm mortar based on the nonlinear finite element theory. The coupling dynamic response between base plate of mortar and soil, barrel and base plate of mortar, tube and projectile is researched to provide a reference to the design of mortar and further optimization of the whole structure.The nonlinear phenomenon is introduced during the launch process, at the same time the nonlinear finite element equation and numerical method are discussed, we analyze two methods for calculation and stability about nonlinear dynamics. Also we discuss the finite element theory of interaction. All of the above provides a theoretical foundation for the subsequent static and dynamic analysis.In order to study the strength of base plate of mortar on the mid-hard soil during firing, a coupling nonlinear finite element model of base plate of mortar and mid-hard soil was built. The nonlinear relations of soil constitutive model and interaction between structure and soil are considered simultaneously in the model. We get the stress distribution law and the dynamic stress curves of base plate of mortar by the means of static analysis and dynamic analysis. At last, we compare the dynamic result with static result, which provides a reference to the further optimization of base plate of mortar.In order to study the dynamic response of barrel caused by the sink of base plate of mortar, we establish the whole flexible model of the mortar to study the dynamic response between barrel and base plate of mortar in different working condition. This study makes a solid foundation for the dynamic analysis of whole artillery.First, we introduce the selection of the clearance between tube and projectile, then study and establish the finite element model of whole artillery. Based on the foundation of last chapters, we increase the projectile with the coupled dynamics model to consider the highly nonlinear interaction between projectile and tube. The dynamic response of whole artillery under different clearances is calculated, which provides a calculation basis for the optimization of the tail of projectile and appropriate clearance.