Session: 02-01-02: Dynamic Loads, Response, Vibration and Alleviation of Aerospace Structures - II

Paper Number: 110427

110427 - Resonance Prediction for an Assembly of Two Parts Having Similar Frequencies 

When designing any structure or equipment, it is always a concern if resonance would occur between parts of that structure/equipment under a vibration input load.

From dynamic characteristics, resonant phenomenon occurs when frequency of the vibration load input is equal or very similar to fundamental frequency of the structure or equipment. As a result, magnitude of response of a part is much higher than the magnitude of load input and can be as high as transmissibility factor Q (=1/(2z)) with z is a damping ratio.

In some cases, ‘double resonance’ might occur if two parts connected together have similar fundamental frequencies ---> This would result in a greater response of the second part that will almost certainly damage it as well as the first part.

Therefore, it is desired to predict if ‘double resonance’ would occur when two parts of an assembly have similar fundamental frequencies and find a way to eliminate this potential issue. This paper is to present a study utilizing both closed form and finite element analysis (FEA) to evaluate vibration response of two parts with similar fundamental frequencies. Results from the study indicate that ‘double resonance’ is dependent on the weight of each part and therefore in some cases, having similar fundamental frequencies might not pose a ‘double resonance’ risk.

Presenting Author: Tuan Nguyen Raytheon Technologies

Presenting Author Biography: Dr. Nguyen's background is in Mechanical Engineering with specialization in finite element analysis and closed form solutions, vibration and dynamics, shocks, acoustics, bolted joint and weld joint calculations. He holds a Ph.D. diploma in Mechanical Engineering as well as Professional Engineer license. His professional experiences have been spanning over 25 years in academic, commercial, and defense industries. He has published more than 17 papers internally and externally.
Currently, he is an Technical Fellow at Raytheon Technologies. He leads structural analysis efforts using finite element analysis codes and closed form solutions. He is also a Subject Matter Expert (SME) at Raytheon Technologies.

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