Limits...
Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges.

Ahmad J, Cheng S, Ghrib F - ScientificWorldJournal (2015)

Bottom Line: While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed.In addition, the damping property of main cables in the network will also be considered in the formulation.The proposed analytical model will be applied to networks with different configurations.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada N9B 3P4.

ABSTRACT
Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

No MeSH data available.


Related in: MedlinePlus

Effect of undamped cross-tie stiffness parameter ψo on modal frequency and modal damping ratio of the lowest in-phase and out-of-phase global modes of an asymmetric DMT cable network.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4488171&req=5

fig6: Effect of undamped cross-tie stiffness parameter ψo on modal frequency and modal damping ratio of the lowest in-phase and out-of-phase global modes of an asymmetric DMT cable network.

Mentions: Besides, a parametric study is conducted for this asymmetric DMT cable network to better understand the effect of cross-tie stiffness and damping on the modal frequency and damping ratio of the network global modes. Figure 6 depicts the modal property variation of the lowest network in-phase global mode and out-of-phase global mode with respect to the undamped cross-tie stiffness parameter ψo. In the analysis, the cross-tie damping coefficient is assumed to be Cc = 1.0 kN·s/m, whereas ψo varies from 0 (rigid) to 1.0, which is a typical range of cross-tie stiffness on real cable-stayed bridges [7]. It can be seen from Figure 6 that overall the modal properties of the out-of-phase global mode are more sensitive to the cross-tie stiffness. As expected, the frequencies of both global modes decrease monotonically with the increase of cross-tie flexibility. Within the studied range of ψo, the frequency of the in-phase global mode decreases by 7% while that of the out-of-phase global mode drops roughly by 18%. In terms of modal damping ratio, since the linear viscous damping model is used for describing cross-tie damping property, a more flexible cross-tie would result in higher relative motion velocity between the cross-tie two ends and thus more contribution to energy dissipation of the oscillating main cables in the network. It is also interesting to note from the figure that while the damping ratio increment rate of the in-phase global mode is more steady when ψo increases from 0 to 1, that of the out-of-phase global mode appears to be gradually decreasing as the cross-tie becomes more and more flexible. In general, the patterns of ψo-Ω and ψo-ξeq curves in Figure 6 imply that although using a more flexible cross-tie would cause some loss in network in-plane stiffness, the energy dissipation capacity could be greatly improved, which is beneficial for cable vibration control.


Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges.

Ahmad J, Cheng S, Ghrib F - ScientificWorldJournal (2015)

Effect of undamped cross-tie stiffness parameter ψo on modal frequency and modal damping ratio of the lowest in-phase and out-of-phase global modes of an asymmetric DMT cable network.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4488171&req=5

fig6: Effect of undamped cross-tie stiffness parameter ψo on modal frequency and modal damping ratio of the lowest in-phase and out-of-phase global modes of an asymmetric DMT cable network.
Mentions: Besides, a parametric study is conducted for this asymmetric DMT cable network to better understand the effect of cross-tie stiffness and damping on the modal frequency and damping ratio of the network global modes. Figure 6 depicts the modal property variation of the lowest network in-phase global mode and out-of-phase global mode with respect to the undamped cross-tie stiffness parameter ψo. In the analysis, the cross-tie damping coefficient is assumed to be Cc = 1.0 kN·s/m, whereas ψo varies from 0 (rigid) to 1.0, which is a typical range of cross-tie stiffness on real cable-stayed bridges [7]. It can be seen from Figure 6 that overall the modal properties of the out-of-phase global mode are more sensitive to the cross-tie stiffness. As expected, the frequencies of both global modes decrease monotonically with the increase of cross-tie flexibility. Within the studied range of ψo, the frequency of the in-phase global mode decreases by 7% while that of the out-of-phase global mode drops roughly by 18%. In terms of modal damping ratio, since the linear viscous damping model is used for describing cross-tie damping property, a more flexible cross-tie would result in higher relative motion velocity between the cross-tie two ends and thus more contribution to energy dissipation of the oscillating main cables in the network. It is also interesting to note from the figure that while the damping ratio increment rate of the in-phase global mode is more steady when ψo increases from 0 to 1, that of the out-of-phase global mode appears to be gradually decreasing as the cross-tie becomes more and more flexible. In general, the patterns of ψo-Ω and ψo-ξeq curves in Figure 6 imply that although using a more flexible cross-tie would cause some loss in network in-plane stiffness, the energy dissipation capacity could be greatly improved, which is beneficial for cable vibration control.

Bottom Line: While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed.In addition, the damping property of main cables in the network will also be considered in the formulation.The proposed analytical model will be applied to networks with different configurations.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil and Environmental Engineering, University of Windsor, 401 Sunset Avenue, Windsor, ON, Canada N9B 3P4.

ABSTRACT
Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

No MeSH data available.


Related in: MedlinePlus