The paper analyzes the structural response of a high-level air blast loaded cable-supported fa？ade. Since the glass panels and the cables present a typical brittle behavior and are subjected to elevated tensile stresses when a high-level explosion occurs, multiple dissipative devices are simultaneously introduced in the conventional glazing system to mitigate the maximum effects of the design blast wave. Dynamic analyses are performed using a sophisticated FE-model to describe accurately the response of the fa？ade equipped by dissipative devices. Based on numerical results of previous contributions, viscoelastic spider connectors (VESCs) are introduced in the points of connection between glass panels and pretensioned cables, to replace “rigid” spider connectors commonly used in practice. At the same time, rigid-plastic frictional devices (RPDs) are installed at the top of the bearing cables to mitigate furthermore the bracing system. As a result, due to the combined use of VESCs and RPDs opportunely calibrated, the maximum tensile stresses in the glass panels and in the cables appear strongly reduced. In addition, the proposed devices do not trouble the aesthetics of such transparent structural systems. At last, simple design rules are presented to predict the response of cable-supported fa？ades subjected to high-level dynamic loads and to preliminary estimate the mechanical parameters of combined VESCs and RPDs. 1. Introduction The effects of air blast loads on the dynamic behaviour of glazing fa？ades constitute a topic of great interest and actuality. Because of this reason, numerous authors recently focused on the typical behaviour of simply supported glass plates subjected to explosions, providing interesting analytical formulations [1–4]. In [5, 6], Wei and Dharani proposed a energy-based failure criterion for laminated glass panes subjected to blast loads, useful to predict the breakage of glass and the size of possible glass shards. Larcher et al. [7], as well as Hooper et al. [8], numerically simulated the behavior of laminated glass panels supported by metallic frames and loaded by air blast waves. In their finite-element (FE) models, the possible cracking of glass was taken into account. Weggel and Zapata [9] and Weggel et al. [10] investigated the dynamic behaviour of a nearly conventional laminated glass curtain wall with split screw spline mullions subjected to low-level blast loading. A unitized curtain wall subjected to high-level blast loads has been recently studied also in [11], and the structural effects of a dissipative system
References
[1]
J. Wei, M. S. Shetty, and L. R. Dharani, “Stress characteristics of a laminated architectural glazing subjected to blast loading,” Computers and Structures, vol. 84, no. 10-11, pp. 699–707, 2006.
[2]
S. Zhao, L. R. Dharani, and X. Liang, “Analysis of damage in laminated architectural glazing subjected to blast loading,” Advances in Structural Engineering, vol. 11, no. 1, pp. 129–134, 2008.
[3]
M. V. Seica, M. Krynski, M. Walker, and J. A. Packer, “Analysis of dynamic response of architectural glazing subject to blast loading,” Journal of Architectural Engineering, vol. 17, no. 2, pp. 59–74, 2011.
[4]
J. Wei, M. S. Shetty, and L. R. Dharani, “Failure analysis of architectural glazing subjected to blast loading,” Engineering Failure Analysis, vol. 13, no. 7, pp. 1029–1043, 2006.
[5]
J. Wei and L. R. Dharani, “Fracture mechanics of laminated glass subjected to blast loading,” Theoretical and Applied Fracture Mechanics, vol. 44, no. 2, pp. 157–167, 2005.
[6]
J. Wei and L. R. Dharani, “Response of laminated architectural glazing subjected to blast loading,” International Journal of Impact Engineering, vol. 32, no. 12, pp. 2032–2047, 2006.
[7]
M. Larcher, G. Solomos, F. Casadei, and N. Gebbeken, “Experimental and numerical investigations of laminated glass subjected to blast loading,” International Journal of Impact Engineering, vol. 39, no. 1, pp. 42–50, 2012.
[8]
P. Hooper, H. Arora, and J. P. Dear, “Blast and impact resistance of laminated glass structures,” in Proceedings of the IMPLAST Symposium on Plasticity and Impact Mechanics, Providence, RI, USA, 2010.
[9]
D. C. Weggel and B. J. Zapata, “Laminated glass curtain walls and laminated glass lites subjected to low-level blast loading,” Journal of Structural Engineering, vol. 134, no. 3, pp. 466–477, 2008.
[10]
D. C. Weggel, B. J. Zapata, and M. J. Kiefer, “Properties and dynamic behavior of glass curtain walls with split screw spline mullions,” Journal of Structural Engineering, vol. 133, no. 10, pp. 1415–1425, 2007.
[11]
C. Amadio and C. Bedon, “Blast analysis of laminated glass curtain walls equipped by viscoelastic dissipative devices,” Buildings, vol. 2, pp. 359–383, 2012.
[12]
X. Zhang, H. Hao, and G. Ma, “Parametric study of laminated glass window response to blast loads,” Engineering Structures, vol. 56, pp. 1707–1717, 2013.
[13]
M. Teich, P. Warnstedt, and N. Gebbeken, “The influence of negative phase loading on cable net facade response,” Journal of Architectural Engineering, vol. 18, no. 4, pp. 276–284, 2012.
[14]
F. Wellershoff, “Design methods and structural components of blast enhanced fa？ades,” in Proceedings of the Challenging Glass 3-International Conference on Architectural and Structural Applications of Glass, F. Bos, C. Louter, R. Nijsse, and F. Veer, Eds., pp. 28–29, IOS Press, Delft, The Netherlands, June 2012.
[15]
F. Wellershoff, G. Lori, M. Zobec, and K. Osterland, “Structural design of blast enhanced cable net facades,” in Proceedings of the COST Action TU0905 Mid-Term Conference on Structural Glass, J. Belis, C. Louter, and D. Mocibob, Eds., pp. 121–131, 2013.
[16]
C. Amadio and C. Bedon, “Viscoelastic spider connectors for the mitigation of cable-supported fa？ades subjected to air blast loading,” Engineering Structures, vol. 42, pp. 190–200, 2012.
[17]
C. Amadio and C. Bedon, “Elastoplastic dissipative devices for the mitigation of blast resisting cable-supported glazing fa？ades,” Engineering Structures, vol. 39, pp. 103–115, 2012.
[18]
GSA-TSO1-2003, “Standard Test Method for Glazing and Window Systems Subject to Dynamic Overpressure Loadings,” U.S. General Service Administration, 2003.
[19]
ABAQUS, v. 6.10, Computer software, Simulia, Dassault Systemes, Providence, RI, USA.
[20]
M. Larcher and G. Solomos, “Laminated glass loaded by air blast waves—experiments and numerical simulations,” Tech. Rep. JRC57559, Joint Research Centre, Pubsy, 2010.
[21]
R.-Q. Feng, L.-L. Zhang, Y. Wu, and S.-Z. Shen, “Dynamic performance of cable net facades,” Journal of Constructional Steel Research, vol. 65, no. 12, pp. 2217–2227, 2009.
[22]
M. L. Lai, P. Lu, D. A. Lunsford, K. C. Chang, and K. Kasai, “Viscoelastic damper: a damper with linear or nonlinear material?” in Proceedings of 11th World Conference on Earthquake Engineering, Acapulco, Mexico, 1996.
[23]
T. T. Song and G. F. Dargush, Passive Energy Dissipation Systems in Structural Engineering, John Wiley & Sons, 1997.
