Analysis Of Load-carrying Capacity Of Engine Cylinder Head Based On Thermal-Mechanical Coupling Method

The load-carrying properties of cylinder head determines the reliability of engine. The cylinder head not only bears the static load which contains bolt pre-tightening force and thermal force, but also the dynamic load. The nodes of cylinder head are oscillating periodic under the dynamic load. It is easy to produce fatigue in the place of stress concentration. For this reason, it is significant to research the load-carrying properties and the reliability of cylinder head under static and dynamic load.In this thesis, the author takes the cylinder head of the small aviation aircraft as research object under the extreme operating conditions. The author uses CFD and FEM to analyze load-carrying Capacity of Engine Cylinder(1) This paper uses the FEM to analyze the static load-carrying properties of cylinder head by building the reasonable FEM model. To compare the load-carrying properties of cylinder head under different load which contains the bolt pretightening force, explosion pressure and combined forces. Than analyzing the distribution of the cylinder head based on fluid-solid coupling method and the load-carrying properties of the head under thermal- mechanical loads by indirect thermal- mechanical coupling method.(2) According to the finite element dynamic theory, the paper calculates the modal and transient response of cylinder head. The paper also analyzes the mechanical response of cylinder head under actual dynamic load and cycle amplitude load.(3)The paper analyzes the fatigue of cylinder head by finite fatigue method. Compare to the fatigue life of head influence by different surface roughness and loading spectrum.Through the different research fields, the cylinder head can satisfy the carrying-load on the extreme operating condition. Also the paper analyses the reason for the stress concentration which can apply the method to optimize the cylinder head in the future.