Control of the Vibration of Simply Supported Beams Using Springs with Proportional Stiffness to the Axially Applied Force

Author(s)

Wahrhaftig, Alexandre de Macedo ; Lima Dantas, Julia Good ; Rebello da Fonseca Brasil, Reyolando Manoel Lopes ; Kloda, Lukasz

• Document type: Journal article
• Source: JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES; v. 10, n. 6, p. 15-pg., 2022-04-25.

Abstract

Purpose In this work, the concept that defines a spring stiffness is established no longer as a function of the induced displacement but through the applied force on the system, an assumption that is evaluated through the theory of vibration of the mechanical systems. Methods A model consisting of a simply supported beam submitted to an axial force that reduces natural frequencies was used to verify the assumed hypothesis. In the system, a translational spring is positioned according to its longitudinal direction, which stiffness is allowed to vary with the magnitude of the applied axial force. The spring, or analogous device, therefore, acting on the beam does not change the natural frequency. First, the model is computationally elaborated by the finite element method and the hypothesis is experimentally tested. Results Differences around 1.5% have been found between the finite element simulations and experimental outcomes. In the case of compressive force approaching the buckling, the average of differences grown to 2.5%. Conclusion Experimental and numerical results prove the constancy of the natural frequency of the beam, even when the system is under the action of an axial force that tends to reduce its structural stiffness and, consequently, to change the frequency of vibration of the system. (AU)

• FAPESP's process: 17/06076-0 - Experimental and numerical study about the geometric nonlinearity on vibrations of rotating machines support structures
• Grantee: Reyolando Manoel Lopes Rebello da Fonseca Brasil
• Support Opportunities: Regular Research Grants