This paper presents vibration analyses performed on a diesel engine mounted on a test chassis. Four methods were used in analyzing engine vibrations on the test chassis. Static engine vibration analysis was an experimental method used to identify natural engine frequencies and modes shapes on the test chassis. In this technique, the non-running engine was excited by an external input force. A running engine analysis was used to determine engine resonance frequencies. In this analysis, the engine was excited by the running dynamics of its components. Engine speeds at those resonance frequencies were also determined in this test. Thirdly, lumped mass modeling was used in analyzing engine vibrations. In this analysis, the engine was analytically modeled as a rigid block. Thus, only inelastic mode shapes of the engine were determined. Finite Element Analysis was the last method performed. In this analysis, both the vibration of the engine and its test chassis were analyzed by finite element modeling. Thus, dynamic mode shapes were determined. Finally, resonance frequencies from all four methods were compared. The experimental natural mode shapes, using the static engine analysis, were correlated with Finite Element Analysis results using the Modal Assurance Criteria formula.
Library of Congress Subject Headings
Diesel motor--Vibration--Mathematical models; Finite element method; Model analysis
Department, Program, or Center
Mechanical Engineering (KGCOE)
Le, Quan, "Vibration analysis of a diesel engine mounted on a test chassis" (1997). Thesis. Rochester Institute of Technology. Accessed from
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