An Internal Combustion (IC) engine is a heat engine that converts chemical energy to thermal energy by the combustion of fuel. The piston, the connecting rod, and the crankshaft of the heat engine further convert the thermal energy to mechanical energy. They also convert the reciprocate motion of the connecting rod to rotary motion. The connecting rod receives thrust of the piston and transfers the thrust to the crankshaft. As a result, mechanical energy is available to the rotary output shaft for traction or other purposes.

You can perform a classical analysis such as a dynamic analysis, or a numerical analysis such as Finite Element Analysis (FEA), on connecting rods to optimize their design. In addition, the analyses minimize the mass of the connecting rod under the impact of different types of load so that the maximum stress lies within the limits of allowable stresses. Mass optimization of connecting rods results in saving raw material and the associated costs. In addition, optimization reduces the overall weight of the engine, thereby reducing inertia loads and weight per unit power, and improving fuel efficiency.

This article explains different types of loads acting on the connecting rod of a heat engine. It describes how to perform classical and numerical analyses to optimize the design of connecting rods and minimize its mass.