Simulation And Analysis On Overturning Behavior Of Metal Diaphragm Based On Parametric Model

The metal diaphragm tank is the core component of the diaphragm tank,which is vital to realize the effective control of propellant.Therefore,propulsion system have a high standard for metal diaphragm.It has an obvious application value to do research on diaphragm’s overturning process.This thesis carries out the simulation work on the overturning process for different kinds of diaphragm,based on the commercial software MSC.Patran/Marc and parametric model,makes a summary of the overturning characteristics,discusses the failure mechanism.Main research contents are as follows:Parameterized modeling techniques for metal diaphragms with secondary development tool Patran Command Language(PCL)are researched,and parameterized modeling program is written.A software for designing and analyzing the metal diaphragm is developed,using C# programming language.The software can realize the fast design and modify of metal diaphragm model,and do overturning process simulation work automatically,which improves the work efficiency significantly.The overturning process of spherical diaphragm is studied.The results show that the joint of flange and the top arc is the key part for structure design.The design of variable thickness performs better than the constant thickness design.The increase of thickness can improve the rollover stability,but effects very limitedly.It also makes the yield load increases,and the initial yield load increase with the thickness linearity.The overturning process of cone cylinder diaphragm is studied.The results show that the cone cylinder diaphragm takes much more propellant,and the difficulty of overturning is increased apparently,which can still accomplish the overturning process.The increase of thickness can improved rollover stability significantly,which also makes the yield load increase,the initial yield load increase with the thickness linearly.Cone Angle influences the yield load negligibly.But has a significant influence on the difficulty of overturning.We suggest to choose the angle design which less than 80.The overturning process of cone dished diaphragm is studied.The results show decentration appears easily for cone dished diaphragm,we suggest choose pure AL as the diaphragm material.The thickness has the same influence on cone dished diaphragm and cone cylinder diaphragm.The hollow depth’s increase can ameliorate the decentration behavior limitedly,whose variation will not affect the post-buckling process yield load,the initial yield load decreases linearly with the increase of hollow depth.The cone angle’s has the same influence with the cone cylinder diaphragm.