Using Finite Element Analysis and Metallographic Analysis to Understand Field Forces on an Industrial Head Gasket

A major concern in head gasket reliability of an industrial diesel engine is flange cracking. This paper will discuss head gasket flange cracking and the head gasket joint environment as they relate to an industrial diesel engine head gasket joint. The paper will discuss metallographic and finite element analysis of head gasket field failures. The metallographic analysis will discuss the evaluation of production, assembled, laboratory tested, and field tested gaskets. The above will give head gasket designers and engine manufacturers insight into the industrial head gasket joint environment. The metallographic work will explain the method of creating micro sections as well as micro section measurements to aid in the understanding of the head gasket loading. By making the metallographic analysis of the production, assembled and laboratory tested gaskets and comparing the results to the field tested gaskets, one can begin to develop a field failure theory for flange cracking for a particular engine application. Likewise, by using finite element analysis, one can study component deformation and component interaction as they relate to the head gasket loading. By studying the component deformation due to thermal stress and combustion gas pressure, the head gasket flange forces can be compared to metallographic analysis. This combination of analyses will result in an understanding of head joint environment forces which produce flange cracking. Once one has an understanding of joint forces one can design a more reliable head gasket joint.