Root causes failure analysis of exhaust manifold heat shield failure

Many internal combustion engines have one or two heat shields that have been ‎installed on the exhaust manifold to avoid the heat transfer to upper parts of the ‎engine, such as the valve cover. In some engines, this part fails due to the ‎fracture and then causes the engine noise and other failures in the engine. In ‎this analysis, root causes of the failure were determined based on the fish bone ‎diagram. In this research, the failure of a heat shield of the spark engine has ‎been investigated and the finite element method (FEM) simulation was used ‎for its design improvement. The analysis of the studied heat shield with the ‎RCA method showed that the malfunction and the assembly problem were both ‎root causes of this failure. Therefore, this part has been produced by ‎dimensional and geometrical approaches. In addition, the heat shield was not a ‎significant problem in the material. Therefore, to prevent this failure, in ‎addition to removing all odds of the production; according to CAE results, have ‎any suggestion for increasing the strength of this part includes the fillet ‎creation, edge bending up or down and the rib creation.‎