Powerplant Mounting System Dynamics Software Development

The powerplant mounting system is one of the most important parts that used to lower the vehicle transmissibility of vibration and improve ride comfort.At present,the powerplant mounting system design theoretical research has been completed.But the software adapted specially for mounting system design and optimization is in short.So the engineers had to use a large scale general dynamic analysis software to design mounting system.It’s very difficult for them to process mass date,which not only put them burden but also the accuracy of the analytical results can’t be guaranteed.So it is crucial to develop a piece of software that dedicated to mounting system design.In this paper,the research project comes from automobile business.Based on the relation theories and the mathematical model of it,a software is developed.Use this software,the following works can be finished:[1] Calculation the modal and the decoupling rate of mounting system.This paper firstly establish the mass and stiffness matrix expression based the derivation of the mounting system kinetic energy and potential energy then the modal analysis mathematical expression is given and an application example is presented to illustrate how to calculate the mode and decoupling rate.[2] Energy decoupling rate optimization.The fgoalatttain and GA algorithm optimization theory is introduced and how to choose design variables,objective function and constraints are also introduced details.The whole procedures of how to optimization in this software are described and the corresponding example is given by using project data.[3] The methods of how to calculate the joint force and displacement of automobile powerplant mounting system is presented in the paper.Base on the mechanical vibration theory,a mathematical model and all the joint equilibrium equation is established.Considering the nonlinear elasticity of bushing by using quasi-Newton method for solving those equations,the joint force and displacement data under the typical condition is obtained.Those accurate data will be a good reference to design mounting restrict structures and check the bracket strength in FEA modal.According to needs,the total five typical condition is analyzed by this software.The example of powertrain mount bracket strength check is illustrated.[4] In the chapter of function modules,the mathematical model of TRA,coordinates conversion and inertial parameter transformation are deduced and those calculation tools are developed.By those tools,the engineer can improve the efficiency of mounting system developing greatly.The example of how to use those tools is still detailed.