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1 – 10 of 315
Article
Publication date: 7 August 2017

Martin Neuenschwander, Claudio Scandella, Markus Knobloch and Mario Fontana

This paper aims to investigate with strain-rate controlled uniaxial cyclic compression tests the softening behavior of concrete and its elastic stiffness degradation with…

Abstract

Purpose

This paper aims to investigate with strain-rate controlled uniaxial cyclic compression tests the softening behavior of concrete and its elastic stiffness degradation with increasing plastic straining.

Design/methodology/approach

Such tests at ambient temperature show that concrete exhibits the phenomenon of elastic stiffness degradation, which can be captured by damage-plasticity models.

Findings

The experimentally derived evolutions of the elastic stiffness with plastic strain confirm the suitability of the damage-plasticity modeling concept for concrete in compression at elevated temperatures and provide novel calibration data.

Originality/value

Temperature-dependent concrete models implementing this modeling concept are often used presently in structural fire engineering, despite the lack of experiment-based validation data.

Details

Journal of Structural Fire Engineering, vol. 9 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 5 January 2010

J. Faleiro, S. Oller and A.H. Barbat

The purpose of this paper is to develop an improved analytical model for predicting the damage response of multi‐storey reinforced concrete frames modelled as an elastic…

1355

Abstract

Purpose

The purpose of this paper is to develop an improved analytical model for predicting the damage response of multi‐storey reinforced concrete frames modelled as an elastic beam‐column with two inelastic hinges at its ends.

Design/methodology/approach

The damage is evaluated in the hinges, using the concentrated damage concepts and a new member damage evaluation method for frame members, which leads to a meaningful global damage index of the structure. A numerical procedure for predicting the damage indices of the structures using matrix structural analysis, plastic theory and continuum damage model is also developed. The method is adequate for the prediction of the failure mechanisms.

Findings

Using the proposed framework numerical examples are finally included. From the obtained results, the advantages and limitation of the proposed model are observed.

Originality/value

The numeric model presented is useful to solve multi‐storey reinforced concrete frames using an inexpensive procedure that combines structural finite elements (beams) of low execution cost, with the moment‐curvature constitutive models deriving from classic stress‐strain ones. The proposed techniques give an inexpensive and reliability procedure to model the frame structures.

Details

Engineering Computations, vol. 27 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 12 March 2020

Tianlai Yu, Linlin Zhang and Zizheng Liu

The fatigue problems of the carriageway slabs of reinforced concrete rib-beam bridges were studied. The analysis of the carriageway slabs could not achieve the actual stress state.

Abstract

Purpose

The fatigue problems of the carriageway slabs of reinforced concrete rib-beam bridges were studied. The analysis of the carriageway slabs could not achieve the actual stress state.

Design/methodology/approach

Based on this characteristic, the reinforced concrete T-beam group structure system was taken as the research object. Four scale models of the carriageway slabs of reinforced concrete ribbed bridges were designed. The fatigue failure modes and actual fatigue resistance of the carriageway slabs with different length-to-side ratios were systematically studied through static load and fatigue experiments. Based on this, the concrete damage plasticity model (CDP model) was combined with numerical simulation analysis to study the influence of the length-to-short-side ratio of the carriageway slab on the fatigue performance and the remaining bearing capacity.

Findings

The results show that the fatigue failure of the carriageway slab is a three-stage failure; the ratio of the long and short sides has a significant effect on the fatigue performance of the carriageway slab. Under the same fatigue load level, the smaller the ratio of the long and short sides of the carriageway slab.

Originality/value

The fatigue resistance of the unidirectional board is significantly lower than that of the bidirectional board. It is recommended to use the bidirectional board in actual engineering design.

Details

International Journal of Structural Integrity, vol. 12 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 2 December 2022

Naveen Revanna and Charles K.S. Moy

This paper employs a textile reinforcement strain comparison to study the response of Textile Reinforced Mortars (TRM) strengthened reinforced concrete one-way slab members in…

Abstract

Purpose

This paper employs a textile reinforcement strain comparison to study the response of Textile Reinforced Mortars (TRM) strengthened reinforced concrete one-way slab members in flexure using the finite element method. Basalt TRM (BTRM) is a relatively new composite in structural strengthening applications. Experimental data on BTRMs are limited in the literature and numerical analyses can help further the understanding of this composite. With this notion, Abaqus finite element software is utilised to create a numerical method to capture the mechanical response of strengthened slab members instead of time-consuming laboratory experiments.

Design/methodology/approach

A numerical method is developed and validated using existing experimental data set on one-way slabs strengthened using Basalt TRMs from the literature. An explicit solver is utilised to analyse the finite element model created using calibrated Concrete Damage Plasticity (CDP) parameters according to the experimental requirements. The generated model is applied to extract load, deflection and rebar strains sustained by strengthened reinforced concrete slabs as observed from the experimental reference chosen. The applicability of the developed model was studied beyond parametric studies by comparing the generated finite element tensile strain by the textile fibre with available formulae.

Findings

CDP calibration done has shown its adaptability. The predicted results in the form of load versus deflection, tensile and compressive damage patterns from the numerical analysis showed good agreement with the experimental data. A parametric study on various concrete strength, textile spacing and TRM bond length obtained shows TRM’s advantages and its favourability for external strengthening applications. A set of five formulae considered to predict the experimental strain showed varied accuracy.

Originality/value

The developed numerical model considers strain sustained by the textile fibre to make results more robust and reliable. The obtained strain from the numerical study showed good agreement with the experiment results.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 28 August 2019

Fatemeh FaghihKhorasani, Mohammad Zaman Kabir, Mehdi AhmadiNajafabad and Khosrow Ghavami

The purpose of this paper is to provide a method to predict the situation of a loaded element in the compressive stress curve to prevent failure of crucial elements in…

Abstract

Purpose

The purpose of this paper is to provide a method to predict the situation of a loaded element in the compressive stress curve to prevent failure of crucial elements in load-bearing masonry walls and to propose a material model to simulate a compressive element successfully in Abaqus software to study the structural safety by using non-linear finite element analysis.

Design/methodology/approach

A Weibull distribution function was rewritten to relate between failure probability function and axial strain during uniaxial compressive loading. Weibull distribution parameters (shape and scale parameters) were defined by detected acoustic emission (AE) events with a linear regression. It was shown that the shape parameter of Weibull distribution was able to illustrate the effects of the added fibers on increasing or decreasing the specimens’ brittleness. Since both Weibull function and compressive stress are functions of compressive strain, a relation between compressive stress and normalized cumulative AE hits was calculated when the compressive strain was available. By suggested procedures, it was possible to monitor pretested plain or random distributed short fibers reinforced adobe elements (with AE sensor and strain detector) in a masonry building under uniaxial compression loading to predict the situation of element in the compressive stress‒strain curve, hence predicting the time to element collapse by an AE sensor and a strain detector. In the predicted compressive stress‒strain curve, the peak stress and its corresponding strain, the stress and strain point with maximum elastic modulus and the maximum elastic modulus were predicted successfully. With a proposed material model, it was illustrated that the needed parameters for simulating a specimen in Abaqus software with concrete damage plasticity were peak stress and its corresponding strain, the stress and strain point with maximum elastic modulus and the maximum elastic modulus.

Findings

The AE cumulative hits versus strain plots corresponding to the stress‒strain curves can be divided into four stages: inactivity period, discontinuous growth period, continuous growth period and constant period, which can predict the densifying, linear, non-linear and residual stress part of the stress‒strain relationship. By supposing that the relation between cumulative AE hits and compressive strain complies with a Weibull distribution function, a linear analysis was conducted to calibrate the parameters of Weibull distribution by AE cumulative hits for predicting the failure probability as a function of compressive strain. Parameters of m and θ were able to predict the brittleness of the plain and tire fibers reinforced adobe elements successfully. The calibrated failure probability function showed sufficient representation of the cumulative AE hit curve. A mathematical model for the stress–strain relationship prediction of the specimens after detecting the first AE hit was developed by the relationship between compressive stress versus the Weibull failure probability function, which was validated against the experimental data and gave good predictions for both plain and short fibers reinforced adobe specimens. Then, the authors were able to monitor and predict the situation of an element in the compressive stress‒strain curve, hence predicting the time to its collapse for pretested plain or random distributed short fibers reinforced adobe (with AE sensor and strain detector) in a masonry building under uniaxial compression loading by an AE sensor and a strain detector. The proposed model was successfully able to predict the main mechanical properties of different adobe specimens which are necessary for material modeling with concrete damage plasticity in Abaqus. These properties include peak compressive strength and its corresponding axial strain, the compressive strength and its corresponding axial strain at the point with maximum compressive Young’s modulus and the maximum compressive Young’s modulus.

Research limitations/implications

The authors were not able to decide about the effects of the specimens’ shape, as only cubic specimens were chosen; by testing different shape and different size specimens, the authors would be able to generalize the results.

Practical implications

The paper includes implications for monitoring techniques and predicting the time to the collapse of pretested elements (with AE sensor and strain detector) in a masonry structure.

Originality/value

This paper proposes a new method to monitor and predict the situation of a loaded element in the compressive stress‒strain curve, hence predicting the time to its collapse for pretested plain or random distributed short fibers reinforced adobe (with AE sensor and strain detector) in a masonry building under uniaxial compression load by an AE sensor and a strain detector.

Article
Publication date: 10 April 2017

Mojtaba Labibzadeh, Mojtaba Zakeri and Abdol Adel Shoaib

The purpose of this paper is to present a new method for determining the input parameters of the concrete damaged plasticity (CDP) model of ABAQUS standard software. The existing…

1088

Abstract

Purpose

The purpose of this paper is to present a new method for determining the input parameters of the concrete damaged plasticity (CDP) model of ABAQUS standard software. The existing available methods in the literatures are case sensitive, i.e., they give different input parameters of CDP for a unique concrete class used in different finite element (FE) simulation of concrete structures. In this study, the authors attempt to introduce a new approach for the identification of the input parameters of the CDP model, which guarantees the uniqueness and precision of the model. In other words, by this method, the input parameters obtained for a specific concrete class with a unique characteristic strength can be used for FE simulation of the different concrete structures which were constructed by this concrete without the need to additional modifications raised from any new application.

Design/methodology/approach

For the input parameter identification of the CDP model, different standard tests of plain concrete are simulated by the ABAQUS standard software. These test simulations are performed for various set of input parameters. In the end, those set of input parameters which represents the best curve fitting with the experimental results is chosen as the optimum parameters.

Findings

By comparison of the FE simulation results obtained from the ABAQUS for two different concrete structures using the proposed input parameters for the CDP model with the experimental results, it was shown that the presented method for determining those parameters can guarantee the uniqueness and precision of the CDP model in simulation.

Originality/value

The method described for determining the input parameters of the CDP model of the ABAQUS standard software has not been previously presented.

Details

International Journal of Structural Integrity, vol. 8 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 26 November 2020

Martyana Dwi Cahyati, Wei-Hsing Huang and Hsieh-Lung Hsu

This study aims to investigate the size effect of the patched repairing material applied to the cracked beam.

Abstract

Purpose

This study aims to investigate the size effect of the patched repairing material applied to the cracked beam.

Design/methodology/approach

Numerical analysis was conducted on a simply supported cracked beam with a dimension of 200 × 25 × 15 cm using ABAQUS software. The behavior of concrete and engineered cementitious composites (ECC) in the simulation are described as concrete damage plasticity model. Linear elastic-plastic model was used to represent the behavior of rebar steel. The type of patching consisted of the varying ratio of lengths and depths, including patching length to total length ratios of 0.2, 0.3 and 0.4, and patching depth to total depth ratios of 0.2, 0.3, 0.4 and 0.5.

Findings

Results show that variations in the patching length and depth ratios affect the maximum flexural load, stiffness and ductility of the repaired beam. It was also found that repairing the cracked beam by using ECC provides higher flexural load of the beam than the use of conventional concrete, owing to the superior tensile strength of ECC.

Originality/value

ECC is the cementitious-based mortar that contains the special selected poly vinyl alcohol fiber having high tensile strength. ECC has been known to exhibit high ductility, high tensile strength and improve durability performance. Thus, ECC is suitable as repairing material for patching cracked beam. By investigating the size of the patched repairing material applied to the cracked beam, the structural performance of repairing beam and the effectiveness of the various patching size were achieved.

Details

World Journal of Engineering, vol. 18 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 27 April 2022

Nadia Talbi, Aghiles Nekmouche, Mohand Ould Ouali, Naceur-Eddine Hannachi and Mohammed Naboussi Farsi

This paper aims to model the performances of frames structures by comparing the predictions of ordinary control concrete (CC) and concretes reinforced by fibers. Two types of…

Abstract

Purpose

This paper aims to model the performances of frames structures by comparing the predictions of ordinary control concrete (CC) and concretes reinforced by fibers. Two types of steel fibers were used in this work, industrial steel fibers (ISF) and tire-reclaimed fibers obtained by cutting virgin steel tire-cord to 50 mm, noticed virgin steel fibers (VSF). In total, 3% of VSF are used. The results obtained in this paper clearly show the contribution of fibers in improving the global and local behavior of the frames structures. VSF gives the same or better overall behavior as the use of industrial fibers for the same percentage of fibers, with the advantage that VSF contributes to the protection of the environment and limit the wastage of steel.

Design/methodology/approach

This work was carried out using the commercial finite element code Abaqus/Explicit. The behavior of the different concretes used in this study was modeled by the concrete damage plasticity (CDP) constitutive law. The methodology adopted to complete this work consisted in identifying, by calibration of the available experimental results with the numerical predictions, the parameters of the corresponding CDP model for each of the concretes used in this work. To this end, the authors have successively identified the CDP parameters for the CC-V (control concrete used by Vecchio and Emara, 1992) used in frame structure (R + 1). Subsequently, the CDP parameters of the CC-T (control concrete used by Tlemat, 2004), the CVSF (concrete with virgin steel fibers) and the CISF-1 (concrete with industrial steel fibers type 1, ISF-1) are identified using the experimental results of beams under bending tests. Once the model parameters were determined for each concrete, the authors conducted a series of simulations to show the benefit of introducing claimed and industrial fibers in frame structure (R + 1) and (R + 2). This approach recommends the use of concrete reinforced with steel fibers, mainly 6% by mass of VSF and ISF-1, in place of ordinary concrete in new construction to increase the resistance of structures and contribute, if applicable, to the protection of the environment.

Findings

The main findings of this study can be summarized by: the strength and ductility of the frames structures made of concrete fiber are significantly increased. The use of tire-reclaimed steel fibers (VSF) gives the same or better overall behavior as the use of industrial fibers. In addition to their good mechanical contribution, the tire-reclaimed fibers contribute to the protection of the environment and limit the wastage of steel. The use of fibers reduces the cracking zones in concrete fiber frames structures. The usefulness of distinguishing the interstory displacement limits set by codes, in particular, uniform building code (UBC-97), for ordinary concretes and concrete reinforced with fibers is addressed.

Originality/value

The contribution of tire-reclaimed and industrial fibers on the strength and ductility of reinforced concrete-frames structures is addressed. The use of tire-reclaimed steel fibers gives the same or better overall behavior as the use of industrial fibers, the tire-reclaimed fibers having the advantage of contributing to the protection of the environment and limiting the wastage of steel. The paper also points to the usefulness of distinguishing the interstory displacement limits set by codes, in particular UBC-97, for ordinary concrete and concrete reinforced with fibers, in accordance to the predictions of the capacity curves.

Details

World Journal of Engineering, vol. 20 no. 5
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 27 November 2023

Maha Assad, Rami Hawileh, Ghada Karaki, Jamal Abdalla and M.Z. Naser

This research paper aims to investigate reinforced concrete (RC) walls' behaviour under fire and identify the thermal and mechanical factors that affect their performance.

Abstract

Purpose

This research paper aims to investigate reinforced concrete (RC) walls' behaviour under fire and identify the thermal and mechanical factors that affect their performance.

Design/methodology/approach

A three-dimensional (3D) finite element (FE) model is developed to predict the response of RC walls under fire and is validated through experimental tests on RC wall specimens subjected to fire conditions. The numerical model incorporates temperature-dependent properties of the constituent materials. Moreover, the validated model was used in a parametric study to inspect the effect of the fire scenario, reinforcement concrete cover, reinforcement ratio and configuration, and wall thickness on the thermal and structural behaviour of the walls subjected to fire.

Findings

The developed 3D FE model successfully predicted the response of experimentally tested RC walls under fire conditions. Results showed that the fire resistance of the walls was highly compromised under hydrocarbon fire. In addition, the minimum wall thickness specified by EC2 may not be sufficient to achieve the desired fire resistance under considered fire scenarios.

Originality/value

There is limited research on the performance of RC walls exposed to fire scenarios. The study contributed to the current state-of-the-art research on the behaviour of RC walls of different concrete types exposed to fire loading, and it also identified the factors affecting the fire resistance of RC walls. This guides the consideration and optimisation of design parameters to improve RC walls performance in the event of a fire.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 6 July 2022

Marya Alraqad, Rabab Allouzi and Amer Alkloub

Short columns can cause serious damage when subjected to an earthquake due to their high stiffness with low ductility. These columns can be exposed to multidirectional shear…

54

Abstract

Purpose

Short columns can cause serious damage when subjected to an earthquake due to their high stiffness with low ductility. These columns can be exposed to multidirectional shear forces, which encouraged this study to investigate the behavior of structural short columns under bi-directional shear.

Design/methodology/approach

Finite element analysis (FEA) using ABAQUS is conducted and calibrated based on experimental data tested by previous researchers who studied the uni-directional behavior of short columns subjected to cyclic shear displacements. Then, the calibrated column models are further investigated to study the influence of bidirectional cyclic shear. Two scenarios are investigated, namely “simultaneous” and “sequential,” to compare the performance in terms of shear strength reduction.

Findings

The results show that the shear strength reduction significantly appears when 1:1 simultaneous bi-directional cyclic shear is applied. However, the shear reduction is more significant when the sequential scenario is applied. The seismic forces or deformations applied in orthogonal directions should be combined to achieve the maximum seismic response of structures as specified in Federal Emergency Management Agency (FEMA) 356 Standard. Finally, the combinations presented in literature to consider bi-directional shear are investigated. Based on FE results, the effect of applied 1:0.30 bi-directional cyclic shear simultaneously does not result in significant effect on the considered columns properly design for seismic forces.

Originality/value

To investigate the effect of multidirectional shear forces on the shear strength capacity of short columns, the presented effect of multidirectional shear forces in literature to consider bi-directional shear are investigated.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

1 – 10 of 315