Title:
Fatigue Tension-Softening Constitutive Model of Normal- Strength Concrete
Author(s):
Hong Chen, Meng-Di Jia, Rena C. Yu, Jian-Jun Zheng, and Zhi-Min Wu
Publication:
Materials Journal
Volume:
122
Issue:
3
Appears on pages(s):
37-50
Keywords:
compressive strength grade; crack propagation; fatigue fracture; tension-softening constitutive model
DOI:
10.14359/51746713
Date:
5/1/2025
Abstract:
The fatigue tension-softening constitutive model of concrete is
a crucial material property for the nonlinear analysis of fatigue
crack propagation processes. However, existing models are derived
and calibrated based on concrete with a single strength grade,
which limits their applicability. To address this issue, this study
develops a fatigue tension-softening constitutive model applicable
to normal-strength grade concrete. First, based on the fracture
test results of three-point bending (TPB) beams, the relationship
between the external work and the energy consumed for fatigue
crack propagation is established using the principle of energy
conservation. The second-order derivative of this relationship is
then used to determine the cohesive stress under fatigue loading.
It is found that the cohesive stress decreases with the increase in
both fatigue crack opening displacement and the number of fatigue
cycles. For a given fatigue load level, the higher the tensile strength
of the concrete, the slower the degradation rate of cohesive stress.
Subsequently, by introducing the number of fatigue cycles, crack
opening displacement, and tensile strength as key parameters, the
fatigue tension-softening constitutive model for normal-strength
concrete is formulated. Finally, the model is validated by using it to
predict the fatigue crack propagation length, fatigue life, and stress
intensity factor at the fatigue failure of TPB beams and comparing
these predictions with experimental results. The model proposed in
this study provides essential parameters for evaluating the fatigue
fracture performance of concrete.