Experiments on the symmetry-breaking effect of orientation on a pair of connected cantilevers. (1st February 2022)

• Record Type: Journal Article
• Authors: Virgin, Lawrence N.; Holland, David B.
• Is Part Of: Mechanical systems and signal processing. Volume 164(2022)
• Publication Date: 2022-02-01
• Subjects: Slender structures -- Modal analysis -- Gravitational effects -- Experimental mechanics; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2021.108236
• Languages: English
• ISSNs: 0888-3270

Abstract

Abstract: It is well established that axial loads tend to influence lateral stiffness and hence natural frequencies of slender structural components. For very slender structures, the axial loading can be caused by self-weight (in a gravitational field), and these effects influence equilibrium configurations and dynamic behavior. In some applications, for example solar sails, attached cables provide an additional complication. This paper will focus attention on a specific form of double cantilever beam system, i.e., two cantilevers sharing a common hub. Two specific cases are considered, in which the two ends of the cantilevers are connected by a cable under a given tensile load. The key observation is the effect that orientation (with respect to gravity) has on breaking the inherent symmetry in the vibration modes shapes of the systems studied. Although theoretical results are available for both a single cantilever pulled by a cable attached to its tip, together with results on the effect of gravity, the focus of the current paper is on the natural frequencies and mode shapes of two-beam systems from an experimental modal analysis perspective. Highlights: Uses experimental modal analysis to examine an interesting feature of structural dynamics. Frequencies and mode shapes illustrate the influence of gravity. Effective use is made of spectrograms. The results show the effect of cable attachments.