Predicting Fracture Placement and Analyzing Fatigue Life in Exhaust Manifold Systems Using Finite Element Analysis

Abstract

The performance of a vehicle's internal combustion engine greatly relies on the Exhaust manifold system, a crucial component that operates under cyclic thermal and mechanical loads due to the engine's operation. However, fracture failure may occur due to these extreme conditions. Therefore, this study aims to perform a simulation for the Von Mises Stress in the first part to determine where we might have maximum stress; this will conduct to accurately predict the fracture placement and analyze it using the finite element (FEM) approach. The study incorporates the widely used Goodman theory in the same field to assess the combined effects of alternating stress and mean stress on fatigue failure. By identifying potential fracture initiation sites and determining the number of load cycles for fatigue failure. Furthermore, this study aims to predict the accurate stress intensity factor (SIF) of a crack propagating in the exhaust manifold which is one of the crucial factors used to assess the remaining fatigue life. The analysis confirms that Mode 1 SIF is the dominant factor contributing to potential fractures in the exhaust manifold.