Validation of the developed triaxial nonlinear material model for concrete

Abstract

This paper presents a validation of newly

developed material model for concrete. The model

is based on a combination of elasto-fractureplastic

formulation, considering all dominant

influences in concrete: yielding in compression,

fracture in tension, softening and hardening. The

modified Mohr-Coulomb criterion for dominant

compression stresses, the modified Rankine criterion

for dominant tension stresses, exponential softening

and the function for hardening are considered in

this model. All constitutive equations are defined by

elementary material parameters (Young’s modulus

of elasticity, Poisson’s coefficient, maximal uniaxial

tensile and compression stresses, the coefficient of

tensile correction, maximal tensile and maximal

compression strains). A multi-surface presentation

of the model is implemented which permits the rapid

convergence of the mathematical procedure. The

model uses return-mapping algorithm for the

integration of the constitutive equations with

associated and non-associated flow rules.

Considering triaxial stress state, the paper presents

the structural validation of a developed numerical

model, which is incorporated into computer

programme PRECON3D, illustrated on four

examples, both experimental and numerical, taken

from the literature: (i) four point bending of normalstrength

and high-strength reinforced concrete

beams with four different constant-zone lengths and

two different reinforcement ratios; (ii) three point

bending of reinforced concrete beam; (iii)

prestressed concrete beam; (iv) prestressed ?-beam.