scholarly journals Reliability assessment of the behavior of reinforced and/or prestressed concrete beams sections in shear failure

2021 ◽  
Vol 15 (57) ◽  
pp. 195-222
Author(s):  
Karim Benyahi ◽  
Mohand Said Kachi ◽  
Youcef Bouafia ◽  
Salma Barboura ◽  
Jia Li

The object of this article is to be able to simulate the behavior of reinforced and/or prestressed concrete beam’s section in the shear loading through a model allowing the evaluation of nonlinear strains caused by shear, while taking into account the real behavior of the materials. In this approach, we are often confronted with problems of modeling uncertainties linked to some insufficiencies of the mechanical model allowing to describe the physical phenomena in a realistic way. For that, it is necessary to use a reliability model making it possible to evaluate their probability of failure, by establishing failure curves according to the different transition zones of the limit state curve of the nonlinear behavior in the shear loading up to at section failure of reinforced and/or prestressed concrete beams. In this work, we also propose a coupling of the reliability method by response surface to carry out the reliability optimization on complex mechanical models, where the mechanical and reliability models developed have been implemented on the Fortran. This allows the estimation in an efficient way of the different reliability characteristics according to each transition zone from the limit state curve to the real behavior until failure in the shear loading.

2015 ◽  
Vol 134 ◽  
pp. 450-459 ◽  
Author(s):  
Mantas Atutis ◽  
Juozas Valivonis ◽  
Edgaras Atutis

2008 ◽  
Vol 400-402 ◽  
pp. 567-573 ◽  
Author(s):  
Wen Zhong Zheng ◽  
Chong Xi Bai ◽  
Hui Dong Cheng

In order to research behaviors of unbonded prestressed concrete beams reinforced with CFRP tendons, static load experiments on 4 partially prestressed simple beams with unbonded CFRP tendons and 9 two spans partially prestressed concrete continuous beams with unbonded CFRP tendons were performed. Based on the experiment results of simple beams, the law of ultimate stress increment in unbonded CFRP tendons in simple beams was obtained. Based on the experiment results of continuous beams, the law of stress increment in unbonded CFRP tendons in continuous beams was obtained at serviceability state and at strength limit state of bending capacity. The calculation formula of length of equivalent plastic hinge for this kind of continuous beam was presented. The calculation formulas of moment modification coefficient with composite reinforcement index for intermediate support as variable and relative plastic rotation for intermediate support as variable were given respectively.


2013 ◽  
Vol 6 (1) ◽  
pp. 13-54
Author(s):  
P. M. Lazzari ◽  
A. Campos Filho ◽  
F. P. S. L. Gastal ◽  
R. A. Barbieri ◽  
R. C. Schwingel

This paper presents a suggestion for the automation of the design procedures of bonded and unbonded prestressed concrete flexural members, according to the Brazilian (NBR 6118:2007) and French (Règles BPEL 91) norm specifications. Prestressing of concrete structures has been increasingly used, mainly due to its building advantages, as well as allowing reducing crack incidence and element dimensions by the use of more resistant materials. Structure is analyzed by a numerical model that employs a hybrid type finite element for planar frames, considering geometric nonlinearity, cyclic loading and composite construction. The computational algorithm implemented considers full, partial and limited prestressing situations, evaluating in each case decompression limit state, limit state of cracking, ultimate limit state and final prestressing state. Finally, two examples comparing design situations according to the Brazilian and French norms are presented.


2011 ◽  
Vol 266 ◽  
pp. 126-129 ◽  
Author(s):  
Zuo Hu Wang ◽  
Xiu Li Du ◽  
Jing Bo Liu

Five beams were tested up to failure to study the shear behavior of concrete beams prestressed with fiber reinforced polymer (FRP). Different factors were taken into consideration: the type of prestressing tendons and the shear span ratio. The shear failure modes and the influence of different factors on shear behavior were investigated in details. The test results showed that FRP prestressed beams without stirrups had two shear failure modes: diagonal compression failure and shear compression failure; the shear span ratio was the most important factor to determine the failure mode and shear capacity of the prestressed beams. The shear capacity of concrete members prestressed with FRP tendons was lower than that of concrete beams prestressed with steel cables.


2012 ◽  
Vol 517 ◽  
pp. 595-600
Author(s):  
Qian Qian Li ◽  
Li Xin Liu ◽  
Sheng Dong He

This paper presents the test results of 2 prestressed concrete beams with manufactured sand under cyclic loading, the concrete is made of manufactured sand to replace natural sand with different replacement rates of 50% and 100%. The stress of re-bars and prestressed strands and the strain of manufactured sand concrete are discussed, the rigidity and cracking of the prestressed beams under cyclic loading are analyzed, and the flexural behavior of the beams after 2.5 million times cyclic loading are also discussed and analyzed. The results show that the fatigue behavior of the prestressed concrete beams with manufactured sand to replace the natural sand under cyclic loading is satisfied, the flexural bearing capacity of the prestressed beams after 2.5 million times cyclic loading is still sufficient. The results also show that the crack width and the mid-span deflection of the prestressed beams are in the allowable range at the serviceability limit state. This may be regarded as a reference for the applications of manufactured sand in the prestressed concrete structure .


2015 ◽  
Vol 8 (3) ◽  
pp. 427-446
Author(s):  
P. K. K. NACHT ◽  
L. F. MARTHA

This work presents an interactive graphics computational tool for the verification of prestressed concrete beams with post-tensioned bonded tendons to the serviceability limit state (SLS) stress check according to the Brazilian code NBR 6118:2014. The tool is an add-in for Autodesk Robot Structural Analysis Professional(r), which serves as a structural modeling platform. With data supplied by the user through a graphics user interface, the program here developed calculates all relevant prestress losses that occur throughout the structure's life-cycle, along with the prestress' equivalent loads during this period. The traditional calculation methods, obtained in the NBR 6118, are presented along with the modifications which had to be implemented in order to allow for incremental loss calculations. Usage examples and results are presented, validating the adopted methodology. At the end of the software's calculation, the user receives two outputs: the prestress' equivalent loads in the Robot model and an Excel spreadsheet. The spreadsheet contains the resultant stresses in the beam and warns whether these are greater than the permissible stresses in the SLS stress check. The loads may then be used in other calculations, such as shear reinforcement.


PCI Journal ◽  
1973 ◽  
Vol 18 (1) ◽  
pp. 39-49
Author(s):  
A. A. Hamoudi ◽  
R. A. Bierweiler ◽  
M. K. S. Phang

Sign in / Sign up

Export Citation Format

Share Document