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Improvement in Modal Testing Measurements by Modeling and Identification of Shaker–Stinger–Structure Interactions

Authors

  • M. Mohammadali,

    Corresponding author
    • Center of Excellence in Experimental Solid Mechanics and Dynamics, School of Mechanical Engineering, Iran University of Science and Technology, Iran
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  • H. Ahmadian

    1. Center of Excellence in Experimental Solid Mechanics and Dynamics, School of Mechanical Engineering, Iran University of Science and Technology, Iran
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Correspondence

M. Mohammadali,

Center of Excellence in Experimental Solid Mechanics and Dynamics

School of Mechanical Engineering

Iran University of Science and Technology

Narmak

Tehran 16844

Iran

Email: mohammadali@iust.ac.ir

Abstract

When a shaker (or exciter) connects to a structure under test (SUT), the dynamic characteristics of the excitation system (shaker, stinger, and transducers) becomes coupled with those of the SUT. These couplings contaminate recorded measurements, especially while exciting light/flexible SUTs. The aim of this work is to consider interactions between excitation system and the SUT and introduce a new analytical model for prediction and hence reducing this systematic error. With the aid of this model, changes in dynamic stiffness of the SUT are estimated based on stiffness of the excitation system. The effects of excitation system location and stiffness are shown in modal testing on a free–free beam. Furthermore, influence of force transducer location is studied in the excitation system setup. The proposed method is successfully used for identification and prediction of excitation system effects on dynamic characteristics of the beam.

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