A Launch System Of Nonlinear Finite Element Structural Dynamics Research

In this thesis, nonlinear finite element analysis of launching system is carried out, simultaneously structural characteristics and dynamics response during marching and launching of self-propelled MLRS are studied with structural dynamics method and nonlinear finite element theory. At the same time, different clearances between ball and pipe, and structural dynamics instantaneous response of launching system of different material directional pipe are analyzed, thus proper clearances and materials of directional pipes are determined. The main contents are as follows: Based on full comprehension of structural principles of launching system, complicated structural dynamics finite element model is set up by use of ABAQUS software. By established finite element model, rigidity and intensity of launching system structure during marching are calculated, validating rationality of structural design. Adopting apparent dynamics method, dynamic response of launching system under different clearances between ball and pipe is analyzed. Then by studying effects of different clearances imposing on initial disturbance, rational clearances are decided. Applying apparent-latent dynamic method, launching system dynamic response of FRP directional pipe and steel directional pipe are calculated respectively. By contrast, the effects of different material directional pipes imposing on overall performances are analyzed. Based on determined clearances and material of directional pipe, considering complicated structure and linking relation, nonlinear structural dynamic research of overall system is carried out, and also frequency analysis of response is studied. Work done in the thesis provides theoretical guidance and optimized design references for structural design and improvement of comprehensive performances.High nonlinear impacting bumping of directional pipe, three centered parts of projectile, screw groove and directional button are considered when establishing structural dynamic finite element model of launching system. When studying material of directional pipe, bumping of ball pipes is considered, thus projectiles are taken to be flexible; simultaneously nonlinearity of non-metal material is considered to make model rational. When studying dynamic analysis, the effects imposing on dynamic characteristics are considered, and dynamic response of launching system under continuous launching is also studied.