Justification of Induced Stresses in Connecting Rod of Two Stroke Petrol Engine through Photo-Elasticity and FEM

Abstract

The connecting rods are subjected to loading which is in a complex state. It undergoes high cyclic loads which are high compressive loads and high tensile loads due to combustion and inertia forces. In this paper, the design of connecting rod for two stroke petrol engines and analysis of stresses by photo-elasticity, analysis software and analytical methods are considered. It is also intended to use different materials so as to give unique solution to use it for two stroke engine. The materials used here are 40C8 carbon steel, forged steel, Cast iron respectively. The connecting rod is first designed by using analytical method and stresses induced are determined. The photo-elasticity models are prepared and analyzed the stress pattern through series of experiments in design laboratory using Research Polariscope. The stress analysis is also carried out through FEM and finally a comparison of all stresses is made. The costs of materials are also compared. It is also suggested to use the connecting rod for the two stroke petrol engines. Key Words: Complex state, inertia forces, Cyclic loads, Connecting rod, Photo-elasticity, FEM etc.