Correlation of Cylinder Head Gasket Sealing Analysis Results between Gasket Element and 3D Continuum Element 2020-01-0049
A head gasket is a component that sits between the engine block/liner and cylinder head(s) in an internal combustion engine. Its purpose is to seal high pressure combustion gasses in the cylinders and to seal coolant and engine oil. It is the most critical sealing application in an engine.
As a general practice, the load deflection(L/D) characteristic is generated by the gasket manufacturer for edge molded or composite gasket types. However, in the case of a solid-sheet metallic gasket, where the gasket is expected to undergo localized yielding to provide adequate conformance and sealing, usually supplier may not be able to provide the required L/D curve due to difficulties to experimentally separate the large loads and small displacements from the elastic loads and deflections of the experimental apparatus. In absence of L/D curve, the typical analysis approach is to model gasket as 3D continuum elements available in ansys by considering nonlinear material and frictional contacts.
The focus of the presented work here is on finite element modeling method to get stable and reliable simulation results. The proposed analysis method relies on a simplified approach for modeling the gasket as gasket elements rather than 3D continuum(solid) elements. This allows for fast and efficient turnaround time. The behavior of the “equivalent” gasket elements is obtained through a 2D axisymmetric analysis of a small section or cross section of the gasket. Here loading & unloading L/D curves initially obtained from 2D-axisymmetric FEA are then considered in a 3D, but selectively/appropriately simplified, FEA model for sealing analysis. Further analysis approach is validated by comparing predicted gasket pressure with experimental Fuji film test and 3D continuum elements FEA results and overall it is observed to be a good match.