A fast stress integration algorithm for reinforced concrete sections with axial loads and biaxial bending

Abstract Reinforced concrete structures may have reduced strength due to the degradation of their mechanical properties by temperature. This can increase the risk of structural collapses. Thus, the structural design should consider its behavior at room temperature and in fire situation (ABNT NBR 14432:2001). This study presents the development of an algorithm to verify the strength of any reinforced concrete sections subjected to unsymmetrical bending at room temperature and in fire situation. For this purpose, a stress integration algorithm was implemented from the strain profile of the section according to ABNT NBR 15200:2012, linked to a finite element mesh generator and a thermal analysis algorithm. For validation of the developed program, called Pisafo, the results obtained were compared with those in the technical literature: obtained in experiments (with differences of up to 28.5%) and with recognized software solutions (with differences of up to -14.8%). The largest variations in relation to the experiments can be attributed to the differences between the thermal properties of the concrete in the experiments with those prescribed in the technical standards used by the program and the non-consideration of spalling in the computational analysis.

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Reliability Assessment of Reinforced Concrete Pylons Subjected to Biaxial Bending

Maintenance, Safety, Risk, Management and Life-Cycle Performance of Bridges ◽

10.1201/9781315189390-150 ◽

2018 ◽

pp. 1107-1114

Author(s):

Ji Hyeon Kim ◽

Hae Sung Lee

Keyword(s):

Reinforced Concrete ◽

Reliability Assessment ◽

Biaxial Bending

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Behaviour of Steel Reinforced Concrete Section with CFRP Wrapping Under Axial Compression

International Journal of Engineering and Advanced Technology - Regular Issue ◽

10.35940/ijeat.a9522.109119 ◽

2019 ◽

Vol 9 (1) ◽

pp. 1955-1958 ◽

Cited By ~ 1

Keyword(s):

Reinforced Concrete ◽

Concrete Columns ◽

Radial Compression ◽

Axial Loads ◽

Structural Element ◽

Reinforced Concrete Column ◽

Element Analysis ◽

Steel Reinforced Concrete ◽

Tubular Columns ◽

Cfrp Wrapping

The composite structural element under study is a carbon fiber wrapped, steel I section reinforced concrete column. The wrapped CFRP is under tension and reinforced concrete under radial compression. The aim of the research is to determine the behavior of the composite structural element under axial loads. The Stress-strain characteristics and load bearing capacity of control and CFRP wrapped tubular columns were determined experimentally. Further, Finite element analysis of steel, reinforced concrete and CFRP wrapped concrete columns sections, was conducted using ANSYS Workbench 15.0 software. The experimental and analytical results were compared.

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Short reinforced concrete column capacity under biaxial bending and axial load

Canadian Journal of Civil Engineering ◽

10.1139/l00-054 ◽

2000 ◽

Vol 27 (6) ◽

pp. 1173-1182 ◽

Cited By ~ 1

Author(s):

H P Hong

Keyword(s):

Reinforced Concrete ◽

Probabilistic Analysis ◽

Axial Load ◽

Failure Surface ◽

Biaxial Bending ◽

Reinforced Concrete Column ◽

Rc Columns ◽

Nonlinear Stress ◽

Modeling Errors ◽

Error Optimization

The paper describes the development of a simple theoretical approach in estimating the capacity of short reinforced concrete (RC) columns under biaxial bending and axial load. The developed approach considers the nonlinear stress-strain relations of concrete and reinforcing steel and does not make the assumption about the limiting strain of extreme compression fiber of concrete. The solution is obtained using a nonlinearly constrained optimization algorithm. The approach was used to estimate the theoretical capacities of many tested RC columns found in the literature. A probabilistic analysis of the modeling errors was carried out using the ratios of the test-to-predicted results. The probabilistic analysis was extended to include two simplified theoretical methods: the reciprocal load method given by Bresler and the failure surface method given by Hsu.Key words: biaxial bending, modeling error, optimization, probability distribution.

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