Date of Award

January 2019

Document Type


Degree Name

Master of Science (MS)


Mechanical Engineering

First Advisor

Djedje-Kossu Zahui


This paper presents a dynamic model of a twin-cylinder internal combustion engine, with focus on balancing the shaking forces and moments. The model will consider five geometry changes to effect second order vibration and nine different engine configurations to reduce first order vibration. An engine that has low vibration is extremely important for both longevity and usability. In order to know how to reduce vibration, we will first study the theory behind internal combustion engine vibration and how to calculate shaking forces and moments. We will follow with utilizing CAE tools, such as FEV Virtual Engine, to simulate engine dynamics. The proposed simulations will allow us to analyze the influence of engine configuration as well as effects of changing components such as piston mass to alter vibration characteristics. Our results will show how the addition of a balance shaft can greatly lower vibration.

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