Nonlinear Finite Element Analysis of Concrete Structures

- 43 -
demonstrates that the model is able to simulate the dilatation
that is characteristic for concrete loaded in compression. The
behaviour of concrete becomes less nonlinear, the more the stress
state involves tensile stresses; this fact is shown in fig. 6 c)
for a biaxial tensile-compressive loading and in fig. 6 d) for
uniaxial and biaxial tensile loadings. The loadings in fig. 6 c)
and 6 d) result in cracking, i.e. a completely brittle failure.
Stress-strain curves for triaxial compressive loading obtained
by means of the classical pressure chamber method and resulting
in failure along the compressive meridian (c, = c~ > ^3) are
shown in both figs. 7 and 8. To indicate their appearance, the
predicted stress-strain curves on these figures are also indicated
at the beginning of the post-failure region, even though
no experimental data were given there.
150
125 -