Question 14.1: Generate moment-curvature curve for a reinforced concrete un...

Section properties:
breadth = 300 mm, depth = 500 mm, clear cover to stirrups = 25 mm

Concrete properties:

f_{ck} = 30 MPa, f^{\prime}_{c} = 25 MPa,\varepsilon_{0} = 0.002, \varepsilon _{cu} = 0.0035 and E_{c}= 27400 MPa

spalling strain = 0.0050
Reinforcing steel properties (hot rolled steel):

f_{y} = 415 MPa, E_{s} = 200000 MPa, f_{u} =  460 MPa, \varepsilon _{u}= 0.12, E_{sh}= 10000 MPa (5% ofE_{s}), diameter of longitudinal bars \phi _{L} = 25 mm, diameter of stirrups \phi _{T} = 10 mm and stirrup spacing x = 150 mm.
The basic relations for generating M-f curve were discussed earlier. These equations were used to derive the moment-curvature curve shown in Figure 14.14. The iterations were done in Excel sheet. The final values of M and f for a given strain level are illustrated in Table 14.6.
Idealized plastic moment = 326 kNm