MDOF Modeling and Blast Dynamic Behavior of Curtain Wall with Variable Damping Approach

In the present paper, a semi-active damping control approach is proposed for the resilient design of façades subjected to extreme loads in the form of blast excitation. A 4 degrees of freedom (4DOF) model is developed to explore the effectiveness of the controlled variable damping, obtained by introducing magnetorheological (MR) dampers at the anchorage points of the curtain wall (CW). The modified Bouc-Wen model is incorporated into the multi-degree of freedom (MDOF) model and fuzzy logic control (FLC) is used to obtain continuously variable command voltage for damper coils, and thereby variable damping in the CW system. Dynamic displacement responses are evaluated for a specific system under different levels of blast loading to assess the structural integrity of the CW components, i.e., the glass and the frame. Pressure-impulse (PI) iso-damage curves are obtained for three damage states: glass cracking, membrane tearing, and frame yielding. Detailed parametric studies are carried out to demonstrate the versatility and superiority of the semi-active controlled variable damping approach toward the blast-resilient design of glass façades.