PSI - Issue 10

N.G. Pnevmatikos et al. / Procedia Structural Integrity 10 (2018) 195–202 N.G. Pnevmatikos et al. / Structural Integrity Procedia 00 (2018) 000 – 000

198

4

(a)

(b)

Fig. 2. The distribution of aftershocks of two earthquakes at Greek region, Lesvos earthquake, (a) and Lefkada earthquake, (b).

fatigue life applying the M iner’s low for a specific detail category. The second way, is related to the low cycle fatigue approach using the main earthquakes sock, consists of the extraction of plastic rotation with non-linear analysis, calculation of the number of deformation cycles using low cycle fatigue model, assess the damage index and fatigue life applying the M iner’s low for a specific detail category. The two approaches are shown in Table 1.

Table 1. High and low cycle fatigue case for barque aftershocks and main shocks. High cycle fatigue case (Using aftershocks) Extract the time history tensile and shear stresses, Convert the time history stresses to an equivalent number of stresses cycles.  Create a stress spectrum.  For each range of stresses calculate the number of cycles from EC3 design chart.  Find the damage index and fatigue life applying the M iner’s low for a specific detail category.   Execute linear time-history analysis of the structure. 

Low cycle fatigue case (Using main shocks)

Execute nonlinear time-history analysis of the structure.  Extract the time history plastic rotation, Convert the time history plastic rotation to an equivalent number of rotation cycles.  Create a plastic rotation spectrum.  Calculate the number of deformation cycles using low cycle fatigue model.  Find the damage index and fatigue life applying the M iner’s low for a specific detail category.