Nonlinear Finite Element Analysis of Concrete Structures

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the load point for both beams. For the beam without shear reinforcement,
horizontal splitting along the tension reinforcement
was observed. The failure was characterized as diagonal tension
failure for the OA-2 beam and shear-compression failure for the
A-2 beam.
The uniaxial compressive strength o and the modulus of rupture
a , were experimentally determined from concrete specimens
cured in the same manner as the beams. The splitting strengths
are estimated from these rupture values using the findings of
Narrow and Ullberg (1963). The o /a -values given in table 1 are
then obtained by approximating splitting strength and uniaxial
tensile strength o.. The assumptions for the remaining parameters
necessary for the constitutive model appear also from this table.
Table 5.3-1: Measured and assumed concrete parameters
Measured
Assumed
c
[MPa]
mod.
[MPa]
E. e
i
c
a /a [loViPa] v. [%] D
OA-2
A-2
23.7 4.3
24.3 3.7
0.10 3.1 0.2 2 0.1
0.08 3.1 0.2 2 0.1
The finite element mesh consists of 1008 triangular plane stress
elements and is shown in fig. 3. Even though no systematic investigations
were performed, this detailed element mesh is moti-
Fig. 5.3-3: Finite element mesh.