higher than its displacement ductility factor by approximately 18%. The curvature

ductility factors for specimens 2, 3 and 4 were approximately the same as the

displacement ductility factors. The difference between the displacement and curvatures

ductility factors for specimens 2 and 4 was approximately 5% and the difference for

specimen 3 was approximately 9%.

Table 5-6. Experimental curvature ductility factors
Specimen Mi Mu ,Oc u [o
 (k-ft) (k-ft) (rad/in.) (rad/in.)
 1 132.0 146.4 0.00053 0.00138 2.6
 2 104.0 122.4 0.00094 0.00184 2.0
 3 129.0 128.0 0.00083 0.00097 1.2
 4 145.0 202.4 0.00099 0.00200 2.0

 The theoretical curvature ductility factors were calculated based on the theoretical

moment-curvature diagrams using the same procedure used for the experimental

curvature ductility factors. The experimental curvature ductility factors are presented in

Table 5-7.

Table 5-7. Theoretical curvature ductility factors
Specimen Mi Mu Oc (u It
 (k-ft) (k-ft) (rad/in.) (rad/in.)
 1 132.0 134.4 0.00133 0.00176 1.5
 2 104.0 130.9 0.00099 0.00168 1.7
 3 129.0 143.1 0.00068 0.00112 1.6
 4 145.0 199.2 0.00072 0.00176 2.4

 The experimental curvature ductility factor for specimen 1 was approximately 1.7

times higher than the theoretical ductility factor. That was attributed to the large

difference between the theoretical and experimental slope of the moment curvature

diagrams. The difference between the theoretical and experimental ductility factors for

specimens 2, 3 and 4 were smaller than the difference for specimen 1. The theoretical

ductility factor of specimen 2 was approximately 15% lower than the experimental