scholarly journals ELASTIC-PLASTIC FRACTURE ANALYSIS OF STRUCTURAL COLUMNS

2006 ◽  
Vol 12 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Abdesselam Zergua ◽  
Mohamed Naimi
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Correlation Study ◽  
Flow Rule ◽  
Elastic Plastic ◽  
Concrete Members ◽  
Proposed Model ◽  
Compression Region ◽  
Frame Work ◽  
Compressive Axial Load

This research is achieved in the general frame‐work of the study of the concrete behaviour. It has for objective the development of a numerical tool able to predict the behaviour of reinforced concrete columns with circular and square cross‐sections under an increasing compressive axial load. The concrete behaviour is assumed as elastic‐plastic model with an associated flow rule in compression region and as elastic with tension stiffening behaviour in the tension region. Two yield surfaces have been taken into account according to the Drucker‐Prager and Rankine failure criterions. However, the reinforcing steel is assumed as an elastic strain hardening model. A finite element method using solid cube elements for concrete, and bar elements for the reinforcement have been used. Correlation study between numerical and experimental results is conducted with the objective to establish the validity of the proposed model and identify the significance of the transverse reinforcement volumetric ratio effect on the response of reinforced concrete members. Good agreement has been observed in comparing these results.

Analysis of Shear-critical reinforced concrete columns under variable axial load

2022 ◽  
pp. 1-24
Author(s):  
Dimitrios K. Zimos ◽  
Panagiotis E. Mergos ◽  
Vassilis K. Papanikolaou ◽  
Andreas J. Kappos
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Full Range ◽  
Element Model ◽  
Independent Verification ◽  
Lateral Response ◽  
Proposed Model ◽  
Compressive Axial Load

Older existing reinforced concrete (R/C) frame structures often contain shear-dominated vertical structural elements, which can experience loss of axial load-bearing capacity after a shear failure, hence initiating progressive collapse. An experimental investigation previously reported by the authors focused on the effect of increasing compressive axial load on the non-linear post-peak lateral response of shear, and flexure-shear, critical R/C columns. These results and findings are used here to verify key assumptions of a finite element model previously proposed by the authors, which is able to capture the full-range response of shear-dominated R/C columns up to the onset of axial failure. Additionally, numerically predicted responses using the proposed model are compared with the experimental ones of the tested column specimens under increasing axial load. Not only global, but also local response quantities are examined, which are difficult to capture in a phenomenological beam-column model. These comparisons also provide an opportunity for an independent verification of the predictive capabilities of the model, because these specimens were not part of the initial database that was used to develop it.

scholarly journals Tension stiffening approach for deformation assessment of flexural reinforced concrete members under compressive axial load

2019 ◽  
Vol 20 (6) ◽  
pp. 2056-2068 ◽  
Author(s):  
Pui‐Lam Ng ◽  
Viktor Gribniak ◽  
Ronaldas Jakubovskis ◽  
Arvydas Rimkus
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Tension Stiffening ◽  
Concrete Members ◽  
Compressive Axial Load

scholarly journals Efficiency of Stress-Strain Models of Confined Concrete With and Without Steel Jacketing to Reproduce Experimental Results

2016 ◽  
Vol 10 (1) ◽  
pp. 65-86 ◽  
Author(s):  
G. Campione ◽  
L. Cavaleri ◽  
M.F. Ferrotto ◽  
G. Macaluso ◽  
M. Papia
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Constitutive Law ◽  
Confined Concrete ◽  
Good Prediction ◽  
Existing Buildings ◽  
Combined System ◽  
Concrete Members ◽  
External Reinforcement ◽  
Strength And Deformation

The improvement and the capacity assessment of existing buildings has become the main topic of the last years so that different studies can be found devoted to damaged structures or structures not having a capacity compatible with the safety levels of the actual codes. Reinforced concrete framed structure buildings represent a conspicuous rate of the existing constructions so many efforts are addressed to them. Referring to this type of buildings, a good prediction of strength and deformation capacity requests models able to interpret the constitutive law of concrete confined by internal reinforcement or by eventual external reinforcement applied to increase capacity of cross-sections. Considering that one of the techniques much diffused for the improvement of the capacity of reinforced concrete members is the steel jacketing by the combined system of angles and battens, models able to predict the real contribution of this kind of intervention are desirable. In this connection the paper discusses the different confined concrete models available in the literature, analyzing all the characteristics and comparing the σ-ε constitutive laws for different type of RC cross sections. Also, an experimental campaign aimed to the validation of the above models is presented. Through the paper, the results of tests on columns reinforced with steel jacketing are described and the reliability of some costitutive laws for concrete confined by steel jacketing is examined.

Deflection of GFRP-reinforced concrete beams

2021 ◽  
pp. 002199832110029
Author(s):  
Katarína Gajdošová ◽  
Róbert Sonnenschein ◽  
Stanislav Blaho
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Fiber Reinforced Polymers ◽  
Concrete Members ◽  
Glass Fiber Reinforced ◽  
Gfrp Reinforcement

This paper presents an investigation of the performance of concrete beams reinforced with glass fiber-reinforced polymers (GFRP) under short-term loading. A total of six specimens with rectangular cross-sections (75 mm in height and 150 mm in width) were tested under a four-point bending test to failure. Each specimen was reinforced with two GFRP bars with diameters of 8 mm. The results of this study demonstrated the behavior of GFRP-reinforced concrete members and a validation of the available calculation methods for the deflection of these members and assumed possibilities of the use of a GFRP reinforcement over the long term. The results of the study presented show a very good agreement of an experimentally measured and theoretically calculated instantaneous deflection when using the approaches in the European and American standards. In calculations of long-term deflections, the results are highly inconsistent and seem to be quite overestimated in some cases. The study shows the necessity of real-time long-term measurements to demonstrate the real deformations to be assumed during design of structures reinforced with GFRP reinforcement.

scholarly journals An effective model for analysis of reinforced concrete members and structures under blast loading

2016 ◽  
Vol 19 (12) ◽  
pp. 1815-1831 ◽  
Author(s):  
Zhongxian Li ◽  
Bo Zhong ◽  
Yanchao Shi
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Damage Effect ◽  
Computational Time ◽  
Isotropic Hardening ◽  
High Fidelity ◽  
Beam Model ◽  
Blast Loads ◽  
Concrete Members ◽  
Proposed Model

The traditional fiber beam model has been widely used in the seismic analysis of reinforced concrete members and structures. However, the inability to capture shear failure restricts its application to blast loadings. In this article, a numerical model that considers both rate-dependent shear behavior and damage effect is proposed based on the traditional fiber beam element. This is achieved using the modified compression-field theory with a concrete damage model and bilinear steel model in the principal directions. Meanwhile, a condensed three-dimensional stress–strain relation from the isotropic hardening plasticity model is implemented to simulate longitudinal reinforcement bars, as large shear strain would be produced under severe blast loads. The proposed model is validated by comparing the numerical and test results. The high-fidelity physics-based finite element model, validated by the same experiment, is also used in the study to prove the efficiency of the proposed model. Case studies of a reinforced concrete beam and a six-story reinforced concrete frame structure subjected to blast loads are then carried out. The results indicate that the proposed model is reliable compared with the high-fidelity physics-based model. In addition to the accuracy, comparisons of the computational time show an excellent performance with respect to the efficiency of the proposed model.

Nonlinear Analysis of Two Shear Walls Using Elastic Plastic Damage Model

2012 ◽  
Vol 182-183 ◽  
pp. 1581-1584
Author(s):  
Lin Lin ◽  
Cheng He Li ◽  
Hu Qi
Keyword(s):  
Static Loading ◽  
Damage Model ◽  
Shear Walls ◽  
Shear Wall ◽  
Damage Distribution ◽  
Elastic Plastic ◽  
Concrete Members ◽  
Plastic Damage ◽  
Proposed Model ◽  
Simulation Results

In this paper, the elastic plastic damage model for concrete under static loading previously proposed by Hu Qi et al. is developed in ABAQUS via UMAT, and it is verified by the simulation of two shear wall members under horizontal loading. The simulation results indicate that this constitutive model can accurately predict typical nonlinear performances of reinforcement concrete shear walls. Using the proposed model one can get the damage distribution of reinforced concrete members which is helpful for researchers to get the failure pattern of structures.

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