Group-theoretic vibration analysis of double-layer cable nets of D4h symmetry

Shallow cable nets may be coupled into multi-layer configurations that are stiffer and stronger than single-layer configurations. In a previous study, group theory was used to investigate double-layer cable nets of D-4h symmetry by reference to a 32-node case study, revealing key insights on their vibration characteristics. In this paper, and as an extension of the previous work, we present a rigorous group-theoretic formulation for the computation of natural frequencies and mode shapes of double-layer cable nets of D-4h symmetry, by reference to the same case study. The analysis reveals the existence of transverse-extension modes that are unique to coupled cable-net configurations, at the same time demonstrating the substantial computational benefits of the group-theoretic procedure. A numerical example is considered in order to illustrate how the eigenvalues and eigenmodes of the problem are actually calculated, providing further insights on the vibration behaviour of the cable net. (C) 2019 Elsevier Ltd. All rights reserved.