Stochastic damage model for bond stress-slip relationship of reinforcing bar embedded in concrete

2019 ◽  
Vol 194 ◽  
pp. 11-25 ◽  
Author(s):  
Le Huang ◽  
Hailong Ye ◽  
Shaohua Chu ◽  
Lihua Xu ◽  
Yin Chi
Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3151 ◽  
Author(s):  
Xiaoyong Lv ◽  
Zhiwu Yu ◽  
Zhi Shan ◽  
Ju Yuan

The stochastic bond stress-slip behavior is an essential topic for the rebar-concrete interface. However, few theoretical models incorporating stochastic behavior in current literature can be traced. In this paper, a stochastic damage model based on micro-mechanical approach for bond stress-slip relationship of the interface under monotonic loading was proposed. In order to describe the mechanical behaviors of the rebar-concrete interface, a microscopic damage model was proposed. By introducing a micro-element consists of parallel spring element, friction element and a switch element, the model is formulated. In order to reflect the randomness of the bond stress-slip behavior contributed by the micro-fracture in the interface, a series of paralleled micro-elements are adopted with the failure threshold of individual spring element is set as a random variable. The expression of both mean and variance for the bond stress-slip relationship was derived based on statistical damage mechanics. Furthermore, by utilizing a search heuristic global optimization algorithm (i.e., a genetic algorithm), parameters of the proposed model are able to be identified from experimental results, which a lognormal distribution has adopted. The prediction was verified against experimental results, and it reveals that the proposed model is capable of capturing the random nature of the micro-structure and characterizing the stochastic behavior.


2011 ◽  
Vol 250-253 ◽  
pp. 636-639
Author(s):  
Shan Suo Zheng ◽  
Yi Hu ◽  
Bin Liu ◽  
Ming Xie ◽  
Qing Lin Tao

The damage evolution laws of high strength and high performance concrete (HSHPC) are obtained by a large number of experiments on mechanical properties. Based on stochastic damage model, a new damage variable with two parameters is proposed to describe the damage constitutive relationship of HSHPC and the damage constitutive equation is established by boundary conditions. Compared mechanical test result of HSHPC with theoretical calculation, it is shown that the damage constitutive equation can reflect the damage characteristics of HSHPC reasonably. The research identifies a certain theoretical basis for further studying on dynamic and stochastic damage constitutive relationship of HSHPC.


Author(s):  
K. J. Thompson ◽  
R. Park

The stress-strain relationship of Grade 275 steel reinforcing bar under cyclic (reversed) loading is examined using experimental results obtained previously from eleven test specimens to which a variety of axial loading cycles has been applied. A Ramberg-Osgood function is fitted to the experimental stress-strain curves to follow the cyclic stress-strain behaviour after the first load run in the plastic range. The empirical constants in the function are determined by regression analysis and are found to depend mainly on the plastic strain imposed
in the previous loading run. The monotonic stress-strain curve for the steel, with origin of strains suitably adjusted, is assumed to be the envelope curve giving the upper limit of stress. The resulting Ramberg-Osgood expression and envelope is found to give good agreement with the experimentally measured cyclic stress-strain curves.


2018 ◽  
Vol 30 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Hye-Jin Lee ◽  
Keun-Hyeok Yang ◽  
Si-Jun Kim ◽  
Sang-Hun Park

2013 ◽  
Vol 47 (6) ◽  
pp. 1025-1039 ◽  
Author(s):  
An Duan ◽  
Ye Tian ◽  
Jian-Guo Dai ◽  
Wei-Liang Jin

2013 ◽  
Vol 17 (7) ◽  
pp. 1700-1707 ◽  
Author(s):  
Rashid Hameed ◽  
Anaclet Turatsinze ◽  
Frédéric Duprat ◽  
Alain Sellier

2013 ◽  
Vol 07 (03) ◽  
pp. 1350027
Author(s):  
JIE LI ◽  
QIAOPING HUANG

A new rate-dependent stochastic damage model for the dynamic modeling of concrete is presented in the paper. This model is formulated on the basis of the stochastic damage model, from which, the static stochastic evolution of damage is strictly derived. Then, rate dependency of concrete is included by means of viscous-damage mechanism. The model predictions are tested against experimental results on concrete specimens that cover different strain rates. The results demonstrate the proposed model may predict dynamic failure behavior of concrete quite well.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guohua Xing ◽  
Cheng Zhou ◽  
Tao Wu ◽  
Boquan Liu

To evaluate the bond behavior between the reinforcing bar and surrounding concrete, a total of six-group pullout specimens with plain steel bars and two-group specimens with deformed steel bars, serving as a reference, are experimentally investigated and presented in this study. The main test parameters of this investigation include embedment length, surface type of reinforcing bars, and bar diameter. In particular, the bond mechanism of plain steel reinforcing bars against the surrounding concrete was analyzed by comparing with six-group pullout specimens with aluminium alloy bars. The results indicated that the bond stress experienced by plain bars is quite lower than that of the deformed bars given equal structural characteristics and details. Averagely, plain bars appeared to develop only 18.3% of the bond stress of deformed bars. Differing from the bond strength of plain steel bars, which is based primarily on chemical adhesion and friction force, the bond stress of aluminium alloy bars is mainly experienced by chemical adhesion and about 0.21~0.56 MPa, which is just one-tenth of that of plain steel bars. Based on the test results, a bond-slip model at the interface between concrete and plain bars is put forward.


Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3295 ◽  
Author(s):  
Hankun Liu ◽  
Xiaodan Ren ◽  
Shixue Liang ◽  
Jie Li

Although considerable effort has been taken regarding concrete damage, the physical mechanism of concrete damage under compression remains unknown. This paper presents, for the first time, the physical reality of the damage of concrete under compression in the view of statistical and probabilistic information (SPI) at the mesoscale. To investigate the mesoscale compressive fracture, the confined force chain buckling model is proposed; using which the mesoscale parameters concerned could be directly from nanoindentation by random field theory. Then, the mesoscale parameters could also be identified from macro-testing using the stochastic damage model. In addition, the link between these two mesoscale parameters could be established by the relative entropy. A good agreement between them from nano- and macro- testing when the constraint factor approaches around 33, indicates that the mesoscale parameters in the stochastic damage model could be verified through the present research. Our results suggest that concrete damage is strongly dependent on the mesoscale random failure, where meso-randomness originates from intrinsic meso-inhomogeneity and meso-fracture arises physically from the buckling of the confined force chain system. The mesoscale random buckling of the confined force chain system above tends to constitute the physical mechanism of concrete damage under compression.


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