Ultra low cycle fatigue (ULCF) is a phenomenon that can be summarily defined as the deterioration of material properties under high amplitude cyclic loading, under which failure is reached typically within ten to twenty cycles. This phenomenon is observed in extreme loading scenarios such as earthquakes or exceptional winds where large cyclic strains are expected. Particularly sensitive are str...

Seismic evaluations of many existing deck-truss bridges have revealed the vulnerability of their substructure and members of their superstructure. An innovative retrofit strategy developed by the authors includes replacement of the existing non-ductile end and lower-end bracing with ductile panels by incorporating energy dissipating devices to act as fuses, which can yield and dissipate energy ...

in this paper, the problem of layout optimization for x-bracing of steel frames is studied using the ant system (as). a new design method is employed to share the gravity and the lateral loads between the main frame and the bracings according to the requirements of the ibc2006 code. an algorithm is developed which is called optimum steel designer (osd). an optimization method based on an approx...

In this work, a tied braced frame (TBF) was developed to achieve uniform inelastic deformation in an eccentrically (EBF) by connecting links across the entire height with tie members. Herein, TBF design method is proposed, considering new lateral force distribution pattern. To better evaluate seismic performance, and verify advantages of TBF, nonlinear time-history analysis fragility were condu...