engleski

Reliability of seismic links in eccentrically braced steel frames

In this paper theoretical and experimental research of the most ductile elements of the eccentrically braced steel frames called seismic links is presented. Four types of short seismic links were chosen, each having the same cross section HEA100 and the same length, but with different number of stiffeners, i. e. with three couples of stiffeners, two, one and without any stiffener on the seismic link length. First of all the nonlinear numerical modelling was conducted by the finite element method. Results of this theoretical analysis served as a base for preparing the scope for experimental analysis. Four series (realized in two sets) of experiments each having four specimen of short seismic links with different number of stiffeners were conducted. The first set of experiments was made on the whole model of eccentrically braced steel frame. The second set of experiments was conducted with the auxiliary structure simulating boundary conditions for links in the real eccentrically braced steel frames. To obtain the degree of reliability of eccentrically braced steel frame the reliability index β was defined on the probabilistic level in relation to target value for the reliability class RC2 according to Eurocode 0 [6]. It has been concluded that the optimum reliability index β is obtained for short seismic links with two and three pairs of web stiffeners for reliability class RC2 and 50 year reference return period.

seismic links; steel frames; reliability index; nonlinear analysis; seismic energy;

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