Research On Parametric Modeling And Modal And Responsive Analysis For Yc485Q Diesel Cylinder Head

Parameterized modeling and modal analysis for YC485Q diesel engine cylinder head is a part of Yu Chai diesel engine YC485Q NVH research and CAE calculation.This paper regards YC485Q diesel engine cylinder head as the research object, set up cylinder head parameterized model in ANSYS, the accuracy of the modal test results verify the finite element model, then the cylinder head vibration characteristic analysis of the cylinder head, the weak part of the structure is improved, so as to reduce the diesel engine cylinder head the largest vibration displacement response of effect. The specific research contents as:1. Using parametric programming languages in ANSYS software, using the characteristic parameters and the size of driving parameters to complete the modeling of geometry parameters of cylinder head structure, the parameters finite element analysis model of the cylinder head structure, provids convenience for the model modification and analysis.2. According to the structure characteristic of cylinder head, we select90response points, establish modal test system of cylinder head, and obtain modal parameters of cylinder head under the free state, the first order natural frequency is1070Hz, which is far away from173Hz-YC485Q diesel engine maximum excitation frequency, and so that we can avoid the occurring of resonanc. Besides, the calculation of the cylinder head free modal FEM, gets the cylinder head of the low order natural frequency and modal shape, and the accuracy of the FEM is verified by experimental modal results, to illustrate the FEM can better reflect the cylinder head vibration characteristics. And small stiffness is in cylinder head exhaust side partial rib and the top.3. Under the YC485Q diesel engine operating conditions, we regards the main cylinder gas pressure in the cylinder head as the exciting force, we do transient responsive analysis of the FEM, and obtain the distribution of displacement and vibration velocity of the cylinder head, it shows that the maximum vibration displacement and the vibration velocity is occur in the each cylinder gas pressure pore structure,is10.2μm and56.9mm/s.4. With improvement of large vibration of the weak parts of the cylinder head, the overall maximum vibration displacement and vibration velocity were decreased by13.7%and9.7%, which achieved good damping effect.The significance of this research is:carrying on the preliminary discussion of establishing the parameterized modeling of diesel engine cylinder head structure, the modal and response results and improvement scheme can provide reference to real cases.