Report - PEER - University of California, Berkeley

constant amplitude loading (CA) or variable amplitude loading (VA). The followingcolumns are the compressive strength of concrete (f c ), axial load level (N/f c A g ),longitudinal reinforcement ratio (ρ 1 ) and transverse reinforcement ratio (ρ t ) and thelow-cycle fatigue parameters α and β calibrated for each specimen in the list. Forvariable amplitude (VA) cyclic test data, an inverse solution procedure is employed toestimate the model parameters. This is achieved by employing a least square fit on theexperimental cumulative dissipated energy versus the number of cycles.Table 1. Properties of R/C beam column specimens under cyclic loadingNoCodefLH cN/fName (MPa) c Aρ l ρ tg(%) (%)α β Class1 WS1 VA 34.7 0.117 2.4 0.3 0.25 0.50 SV2 WS2 VA 34.7 0.117 2.4 0.3 0.30 0.30 SV3 WS3 VA 26.1 0.147 2.4 0.5 0.55 0.60 MD4 WS4 CA 33.5 0.115 2.4 1.5 0.85 0.20 SL5 WS5 CA 33.5 0.115 2.4 1.5 0.90 0.30 SL6 WS6 VA 33.6 0.071 2.4 0.3 0.60 1.20 MD7 SO1 VA 43.6 0 3.2 0.9 0.25 0.60 SV8 SO2 VA 34.8 0.141 3.2 1.7 0.60 0.40 MD9 SO3 VA 32.0 0.153 3.2 2.5 0.80 0.60 SL10 SO4 VA 37.3 0.131 3.2 2.0 0.95 0.30 SL11 SO5 VA 39.0 0.126 3.2 2.0 0.95 0.40 SL12 ES1 CA 20.6 0 1.3 0.8 0.16 0.75 SV13 ES2 CA 21.2 0 1.3 0.8 0.26 1.16 SV14 ES3 CA 20.6 0 1.3 0.8 0.23 0.81 SV15 ES4 VA 20.6 0 1.3 0.8 0.15 0.80 SV16 ES5 VA 21.2 0 1.3 0.8 0.30 0.90 SV17 ES6 VA 21.2 0 1.3 0.8 0.15 0.50 SV18 PJ1 VA 33.7 0.085 2.5 0.6 0.50 0.20 MD19 PJ2 CA 29.9 0.096 2.5 0.6 0.45 0.30 MD20 PJ3 CA 27.4 0.104 2.5 0.6 0.55 0.20 MD21 PJ4 CA 36.4 0.158 2.5 0.6 0.65 0.30 MD22 PJ5 VA 34.9 0.082 2.5 0.6 0.60 0.20 MDIn the last column of the table, the specimens are classified according to theirestimated low cycle fatigue parameters. The abbreviation “SL” denotes theoretically anon-deteriorating, or in practice a slightly deteriorating system with α parametercloser to unity and β parameter closer to zero. Examples of this sort of behaviorbelong to test specimens WS4-5, SO3-5. For these specimens, parameter α rangesbetween 0.80-0.95 and parameter β ranges between 0.2-0.6. The force-displacementrelationship for SO4 is shown in Figure 2.a. It represents a desired seismic behaviorwith stable loops and with little stiffness and strength deterioration.424