Numerical and statistical analysis about displacements in reinforced concrete beams using damage mechanics

2012 ◽  
Vol 10 (3) ◽  
pp. 307-330 ◽  
Author(s):  
Jose J. De C. Pituba ◽  
Rodrigo G. Delalibera ◽  
Fabio S. Rodrigues
2016 ◽  
Vol 9 (2) ◽  
pp. 153-191
Author(s):  
W. M. Pereira Junior ◽  
D. L. Araújo ◽  
J. J. C. Pituba

ABSTRACT This work deals with numerical modeling of the mechanical behavior of steel-fiber-reinforced concrete beams using a constitutive model based on damage mechanics. Initially, the formulation of the damage model is presented. The concrete is assumed to be an initial elastic isotropic medium presenting anisotropy, permanent strains, and bimodularity induced by damage evolution. In order to take into account the contribution of the steel fiber to the mechanical behavior of the media, a homogenization procedure is employed. Finally, numerical analyses of steel-fiber-reinforced concrete beams submitted to bending loading are performed in order to show the good performance of the model and its potential.


2018 ◽  
Vol 11 (1) ◽  
pp. 26-51 ◽  
Author(s):  
G. P. PELLIZZER ◽  
E. D. LEONEL ◽  
C. G. NOGUEIRA

Abstract Every structure is subjected to the effects of time and environment on which they are located. The consideration of these effects and their consequences in design phase is called nowadays as durability analysis of the structural system. The corrosion of the reinforcement steel through the chloride penetration inside the concrete is the main cause of the lifetime deterioration of the reinforced concrete structures. As a direct consequence, the corrosion affects the resistant capacity of the structural elements as the process evolves over time. Therefore, the appropriate prediction of the structural lifetime depends directly of the prevision capacity of those effects over the behavior of the structural systems. In this work, a mechanical model that combines the corrosion effects over the reinforcement and the concrete and steel material nonlinear responses is proposed to predict the resistant loss of reinforced concrete beams over the time. The steel and concrete nonlinear behavior was modeled by model based on unidimensional plasticity theory and damage mechanics, respectively. The Fick’s laws and empirical methods based on the Faraday’s laws were used to represent chloride penetration inside concrete and reinforced degradation, respectively. A simplified process was adopted to simulate the corrosion beginning in different times over the structure. The results showed that the rate of loss resistant capacity of the analyzed beam is higher in the first years after the beginning of corrosion and tend to stabilized in subsequent years. Furthermore, the structural behavior is very sensitive regarding the considered corrosive effects in the analyses.


2020 ◽  
Vol 14 (54) ◽  
Author(s):  
Thalyson Brito ◽  
Danilo Santos ◽  
Fabio Santos ◽  
Rafael Cunha ◽  
David Amorim

The analysis of reinforced concrete structures can be performed by means of experiments or numerical studies. The first way is usually quite expensive, so the second one sometimes is a good option to understand the physical behaviour of actual structures. Lumped damage mechanics appears as one of the latest nonlinear theories and presents itself as an interesting alternative to analyse the mechanical behaviour of reinforced concrete structures. The lumped damage mechanic applies concepts of the classic fracture and damage mechanics in plastic hinges for nonlinear analysis of reinforced concrete structures. Therefore, this paper deals with a novel physical definition of the correction factor γ for cracking evolution that ensures the presented lumped damage model depicts accuracy when it is compared to experimental observations of reinforced concrete beams and arches. Based on such experiments, the numerical analysis showed that γ value has upper and lower thresholds, depending on the physical and geometric properties of the reinforced concrete element. Notwithstanding, for γ values inside of the proposed interval, there is a best value of γ.


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