Structures Subjected to Low-Level Blast Loads: Analysis of Aerodynamic Damping and Fluid-Structure Interaction

Abstract

This paper presents the structural behavior of idealized linear single-degree-of-freedom systems subjected to weak blast loads. The authors derive a new coupling model taking into account fluid-structure interaction (FSI) and aerodynamic damping resulting from the surrounding air. This model contributes to a better understanding of the physical coupling phenomena and can be used for the validation of more complex numerical models. Especially mass and stiffness determine the effects of aerodynamic damping and FSI on the deformations, internal forces, and energy contributions. Although the coupling effects are negligible for stiff or heavy systems (e.g., reinforced concrete structures), they significantly influence the structural response of flexible and light systems (e.g., membrane structures or glazing facades). On the basis of the new coupling model, the authors derive a decoupled model incorporating aerodynamic damping and FSI effects. This decoupled model is derived on the basis of an equivalent viscous damping ratio depending on mass and structural stiffness. Finally, a response spectrum is derived, synthesizing the discussed results.