Study, Based On The Valve Train Dynamic Characteristics Of Multi-body System

Vavle-train not only influences the realiabilty of engine directly, but also does the performance of it. With the development of engine technique, there are more questions and deeply study on valvetrain dynamics. Many dynamics test method and dynamics model have been applied to the research of valvetrain.Multi flexible body dynamics is the most active research field of mechanics in lately twenty years just like the finit element technique in the past. In this paper, Vavletrain as the research object is studied by the theory of multi flexible body dynamics. Multi rigid body dynamics model is built by software MSC.Admas , and Multi flexible body dynamics model is also build through the software Patran and Nastran, which mesh and yield flexible body, such as flexible-body-spring etc.Valvetrain test research is carried on, so that the comparasion difference between calculation results of two dynamic models and dynamic strain computation method's validity is made through test data including the vavle acceleration and rod dynamic strain. In the end, flexible body valve's dynamics response, flexible body spring's nonlinear dynamic stiffness and dynamic stress, are analyzed detailedly in multi flexible body dynamics model.It is concluded through the study of this paper, that the method of building multi flexible body dynamics model can analyze dynamics response of valvetrain well and truly, and detailed dynamic stress result can be gained from the flexible body which is built based on the modal synthesis method which can make flexible body's fatigue performance reseach more rapidly.