Nonlinear Finite Element Analysis of Concrete Structures

to
no softening
writer's criterion
experimental
failure load —
modified Coulomb criterion
experimental data
2 3 4 5
CENTRE DEFORMATION 6lmml
Fig. 5.2-9: Experimental and calculated centre deflections.
criterion (1977) is used again. In fact, the calculations were
stopped at p = 49.1 MPa without impending failure and it emphasizes
the importance of inclusion of a realistic post-failure
behaviour in a constitutive model. This requirement is obviously
more pertinent the more inhomogeneously the structure is
loaded as stress redistribution then becomes essential. This
effect is illustrated in fig. 10, where the contour lines for
the nonlinearity index in per cent at p = 49.1 MPa are shown for
the case of no-softening. A comparison with fig. 8c) demonstrates
clearly the structural mechanism related to the assumpno-softening.
p = 49.1 MPa
Fig. 5.2-10: Contour lines for the nonlinearity index
in per cent. Pressure = 49.1 MPa. Nosoftening
in the post-failure region is
assumed.