ABSTRACT
Energy based structural computation (analysis and design) has achieved a strong position in nowadays theoretical and practical approaches in seismic protection Civil Engineering. Since the first formulation of seismic design in terms of structural demand energy [1], evaluation of structural behavior under seismic actions became a familiar technique in both, seismic analysis [2], [3] and seismic protection practice [4], [5]. In this context, present contribution introduces a theoretical tool to evaluate (in the design stage) the efficacy of designed structure (with or without a system of seismic protection) to dissipate seismic input energy. Proposed technique is synthetic and expresses instantly and in a simple way the capacity of the structure to absorb energy during seismic action. It consists in computing the ratio ε of demand energy (Ei – Ed) to seismic input energy Ei at every instant of seismic action:
Seismic time history analyses have been performed on a set of three designed six story structures and laboratory testing (using a shaking table) on three scaled down structures have been carried out. The effectiveness of seismic protection is computed via proposed ε and emphasized numerically and graphically.
