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Article
Publication date: 17 December 2021

Malika Belhocine, Youcef Bouafia, Mohand Said Kachi and Karim Benyahi

The calculation and design of the structures are carried out with the aim of obtaining a sufficiently ductile behavior to allow the structure to undergo displacements…

Abstract

Purpose

The calculation and design of the structures are carried out with the aim of obtaining a sufficiently ductile behavior to allow the structure to undergo displacements, without risk of sudden breaks or loss of stability. The purpose of this study is to develop and validate a computer program (Thin beam2), allowing the modeling and simulation of the nonlinear behavior of reinforced concrete elements, on the other part, it is estimating the local and global ductility of the sections or elements constituting these structures.

Design/methodology/approach

The authors present two nonlinear analysis methods to carry out a parametric study of the factors influencing the local and global ductility of reinforced concrete structures. The first consists in evaluating the nonlinear behavior at the level of the cross-section of the reinforced concrete elements used in the elaborate Sectenol 1 program, it allows us to have the local ductility. The second, allows us to evaluate the nonlinear behavior of the element used in the modified thin beam 2 program, it allows us to estimate the overall ductility of the element.

Findings

The validation results of the Thin beam2 program are very satisfactory, by conferring the analytic and experimental results obtained by various researchers and the parametric study shows that each factor such as the compressive strength of the concrete has a favorable effect on ductility. Conversely, the normal compression force and the high resistance of tensioned reinforcements adversely affect ductility.

Originality/value

The reliability of the two programs lies in obtaining the local and global ductility of reinforced concrete structures because the calculation and design of the structures are carried out with the aim of obtaining ductile behavior without risk of breakage and instability.

Details

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

Keywords

Article
Publication date: 1 April 1997

D. Mukherjee

The surface science and engineering discipline has emerged recently and become more high‐profile. Functional performance of the surface is given top priority, although…

296

Abstract

The surface science and engineering discipline has emerged recently and become more high‐profile. Functional performance of the surface is given top priority, although some of the bulk parameters play a very important role in the performance of the surface. Residual ductility is one such parameter, which directly controls the probability of surface embrittlement during the service stage of any engineering product, thereby controlling the embrittlement‐induced galvanic corrosion. Residual ductility also indirectly controls the metal dissolution in a corrosive environment by improving the adhesion of the corrosion product films to the surface. Discusses the role of residual ductility, in the control of environmentally induced deterioration of the metallic surfaces, highlighting the parameters which may eventually interfere with its level on the surface. Improvement of ductility also improves the attachment of the nearest neighbour elements of the matrix, resulting in the improvement of the surface stability. On the contrary, a brittle surface undergoes higher reactive interaction with the environment. Also discusses the possibility of using the residual ductility parameter for obtaining the rate values of an imaginary defect for subsequent extrapolation of the approximate residual life values of some carbon‐steel materials.

Details

Anti-Corrosion Methods and Materials, vol. 44 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 January 1988

W. Engelmaier and A. Wagner

With the fatigue ductility test the ductility of metallic foils and flexible metal foil/dielectric laminates can be determined. Ductility together with tensile strength…

Abstract

With the fatigue ductility test the ductility of metallic foils and flexible metal foil/dielectric laminates can be determined. Ductility together with tensile strength allows prediction of the fatigue behaviour of flexible printed wiring (FPW) in both the low‐cycle/high‐strain (ductility dependent) and the high‐cycle/low‐strain (strength dependent) ranges. However, for laminates and FPW with Kapton as the dielectric the standard fatigue ductility test method does not produce the expected results and flex life predictions deviate from experimental results. The results of a study to determine the cause of this anomalous behaviour of Kapton FPW and to find correlative correction procedures are reported. Corrections to account for both the cyclic strain‐hardening of rolled annealed copper foil and the Kapton/adhesive/copper interactions for asymmetric single‐sided FPW are presented. With these corrections the ductility determination for copper foil laminated to a Kapton substrate using the fatigue ductility test produces good results, and the fatigue life of symmetric Kapton FPW can be predicted from the copper foil properties. The underlying mechanisms for the strong deviational flex behaviour of asymmetric single‐sided FPW could not be identified. The recommendation is made that for high‐cycle flex applications the FPW construction be precisely symmetrical. FPW made from copper‐clad Kapton with rolled annealed copper foil is the overwhelming choice and it is important that one has proper acceptance criteria at incoming inspection and that a valid prediction methodology for FPW flexural resistance and fatigue behaviour is available.

Details

Circuit World, vol. 14 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 4 March 2016

Esther Moreno, Alfonso Cobo and Maria Nieves Gonzalez

One of the meaningful effects of concrete reinforcement steel corrosion on concrete structures is the decrease of mechanical properties, specifically the ductility of…

Abstract

Purpose

One of the meaningful effects of concrete reinforcement steel corrosion on concrete structures is the decrease of mechanical properties, specifically the ductility of steel. The term ductility of steel refers to a group of properties which determine the reinforced concrete structures and it is necessary to take this property into account for the recalculation of structures that have been already corroded until the point to condition in many occasions the analysis methodology.

Design/methodology/approach

This research studies the variation on ductility of concrete embedded steels bars after going through an accelerated corrosion process. Tensile strength of high ductility reinforcements with different corrosion levels has been tested. Ductility was studied in terms of ultimate tensile strength, yield strength, ultimate strain, energy density of deformation and “equivalent steel” criterion. It also makes some considerations about what is the best methodology of structural analysis according to the obtained results.

Findings

Based on the obtained results, conclusions are established that determine whether the corroded steel satisfy the requirements of different codes in order to identify them as “steels with special characteristics of ductility” assessing in each case the possibility of reallocating solicitations in structures which might need to be repaired.

Originality/value

The analysis of existing RC structures should address moment redistribution to be able to compare ultimate strength values, rather than to a single value obtained with elastic linear models to a range of values centred on the elastic and linear values obtained and defining an interval equal to double the value of the maximum redistribution capacity. This greatly enhances the possibility of “saving” a standing structure. In ductile structures the effect of actions can be distributed. The ascertainment of corroded reinforcement ductility variation is of key importance in structural re‐engineering and recalculation of structures. The research developed in this article is motivated by the need to contribute to knowledge of the behavior of reinforced concrete structures with reinforcement damaged.

Details

International Journal of Structural Integrity, vol. 7 no. 2
Type: Research Article
ISSN: 1757-9864

Article
Publication date: 4 August 2021

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static…

Abstract

Purpose

This study aims to present comprehensive nonlinear material modelling techniques and simulations of reinforced concrete (RC) beams subjected to short-term monotonic static load using the robust and reliable general-purpose finite element (FE) software ANSYS. A parametric study is carried out to analyse the flexural and ductility behaviour of RC beams under various influencing parameters.

Design/methodology/approach

To develop and validate the numerical FE models, a total of four experimentally tested simply supported RC beams are taken from the available literature and two beams are selected from each author. The concrete, steel reinforcements, bond-slip mechanism, loading and supporting plates are modelled using SOLID65, LINK180, COMBIN39 and SOLID185 elements, respectively. The validated models are then used to conduct parametric FE analysis to investigate the effect of concrete compressive strength, percentage of tensile reinforcement, compression reinforcement ratio, transverse shear reinforcement, bond-slip mechanism, concrete compressive stress-strain constitutive models, beam symmetry and varying overall depth of beam on the ultimate load-carrying capacity and ductility behaviour of RC beams.

Findings

The developed three-dimensional FE models can able to capture the load and midspan deflections at critical points, the accurate yield point of steel reinforcements, the formation of initial and progressive concrete crack patterns and the complete load-deflection curves of RC beams up to ultimate failure. From the numerical results, it can be concluded that the FE model considering the bond-slip effect with Thorenfeldt’s concrete compressive stress-strain model exhibits a better correlation with the experimental data.

Originality/value

The ultimate load and deflection results of validated FE models show a maximum deviation of less than 10% and 15%, respectively, as compared to the experimental results. The developed model is also capable of capturing concrete failure modes accurately. Overall, the FE analysis results were found quite acceptable and compared well with the experimental data at all loading stages. It is suggested that the proposed FE model is a practical and reliable tool for analyzing the flexural behaviour of RC members and can be used for performing parametric studies.

Details

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

Keywords

Article
Publication date: 30 October 2019

Sheng-cai Li and Guo Lin

The purpose of this paper is to study the seismic performance of the energy-saving block and invisible multi-ribbed frame composite walls (EBIMFCW), changing the…

Abstract

Purpose

The purpose of this paper is to study the seismic performance of the energy-saving block and invisible multi-ribbed frame composite walls (EBIMFCW), changing the shear-span ratio as the test parameter, the low-cycle reciprocating loading tests of six 1/2 scale wall models were carried out.

Design/methodology/approach

The test design method and analysis are used for the seismic performance of the EBIMFCW.

Findings

With the increase of shear-span ratio: the walls tend to occur bending failure even more, the initial stiffness of the wall decreases, the overall ductility of the wall is improved and the walls tend to occur bending failure.

Originality/value

The previous studies do not involve the seismic performance of EBIMFCW under different shear-span ratios. Therefore, the paper studies the hysteresis behavior, ductility, stiffness degradation and energy dissipation performance of EBIMFCW under different shear-span ratios.

Details

International Journal of Structural Integrity, vol. 11 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 January 1983

P.M. Smith

This paper examines the behaviour of acid copper baths with regard to ductility. The necessity for a fast and consistent method of measuring ductility is emphasised and…

Abstract

This paper examines the behaviour of acid copper baths with regard to ductility. The necessity for a fast and consistent method of measuring ductility is emphasised and various established techniques and their drawbacks are discussed. The more recently developed procedure, the Duktilomat method, is detailed and its success analysed.

Details

Circuit World, vol. 9 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 31 December 2019

Sassan Eshghi and Mohammad Mahdi Maddah

Mid-rise steel moment-resisting frames (MRFs) with intermediate ductility are a major part of conventional residential buildings in Iran. According to Iranian seismic…

Abstract

Purpose

Mid-rise steel moment-resisting frames (MRFs) with intermediate ductility are a major part of conventional residential buildings in Iran. According to Iranian seismic design codes, in this resisting system, considering the strong-column/weak-beam (SCWB) criterion is not mandatory. Where a metal deck ceiling system is used, the composite action of a concrete slab and steel beams could change the collapse mechanism of the structure, especially in the MRFs with intermediate ductility. The purpose of this paper is to investigate the influence of the composite action in the seismic collapse risk of this type of structures. Seismic collapse risk assessment can be carried out by using simplified pushover-based methods. In these methods, the cyclic deterioration of an equivalent single degree of freedom (ESDoF) system must be considered when the modified Ibarra–Medina–Krawinkler is used for nonlinear modeling of MRFs. Accordingly, a modified method is developed to use in simplified collapse risk assessment process. For these purposes, two mid-rise MRFs with intermediate ductility located in Tehran have been selected as case studies. The results confirm that the composite action is very effective in collapse risk value in the steel MRFs in which their SCWB ratio is less than 1. Moreover, the proposed approach of considering the cyclic deterioration of ESDoF systems increases the accuracy of the simplified collapse assessment approaches.

Design/methodology/approach

Identifying seismically vulnerable buildings to collapse requires using robust methods. These methods can be simplified based on pushover analysis methods. An attempt was made to apply one of these approaches for steel MRFs with intermediate ductility. In these frames, the composite action of a concrete slab and steel beams could change the collapse mechanism. Here, two MRFs were investigated in order to assess this effect on collapse risk value. This process was done by modifying the SPO2IDA method as a simplified collapse capacity evaluation approach by developing a relationship to consider the cyclic deterioration effects for the ESDoF systems.

Findings

The results showed that it is necessary to consider the slab effects in the analytical model in the collapse assessment process of MRFs with intermediate ductility, especially in the condition in which the SCWB ratios of the frame are less than 1. Furthermore, by utilizing the proposed method of considering the ESDoF cyclic deterioration, the error values of the SPO2IDA program were reduced significantly. Moreover, estimating the collapse risk parameters shows that the utilized simplified method presents suitable accuracy and could be an acceptable approach to collapse risk assessment of mid-rise steel MRFs.

Originality/value

The influence of the composite action in seismic collapse risk of MRFs with intermediate ductility is investigated. Also, a modified relationship is developed to consider the deterioration effects on the ESDoF parameters used in simplified collapse risk assessment process. Also, a framework is presented for utilized methodology.

Details

International Journal of Structural Integrity, vol. 11 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 July 1955

Alan V. Levy and Robert Wickham

The great fluidity of titanium metal in the molten condition lends itself to fusion welding without the addition of filler metal. The resulting welds are flush with the…

Abstract

The great fluidity of titanium metal in the molten condition lends itself to fusion welding without the addition of filler metal. The resulting welds are flush with the base metal and have high ductility, comparable to the ductility of the base metal. The welded joints can be made by hand or automatic methods. A critical requirement of this type of weld is fit‐up of the parts to be joined. The back‐up and hold‐down fixtures also have a decided effect on the resulting weld. A sheared surface resulting in a joint without gaps is required for a satisfactory weld. Fused welds have been principally used, to date, for longitudinal tight butt joints in material up to .062 in. thick. Further testing and experience should extend the limits of application. Bend tests made on welded samples have bent 180 deg. over a 2T bend radius exhibiting equal or greater ductility than the base metal. Welds tested in tension have exhibited over 100 per cent efficiency in all cases. The elimination of welding rod has reduced the amount of contamination in the weld and the weld area.

Details

Aircraft Engineering and Aerospace Technology, vol. 27 no. 7
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 March 1984

Dear Sir, The reply (in Vol. 10, No. 2, 1984) from Messrs P. M. Smith and R. Rolff to my correspondence regarding Mr Smith's paper ‘A New Method of Testing the Ductility

Abstract

Dear Sir, The reply (in Vol. 10, No. 2, 1984) from Messrs P. M. Smith and R. Rolff to my correspondence regarding Mr Smith's paper ‘A New Method of Testing the Ductility of Electroplated Foil’ in your February 1983 issue cannot stand without a further retort from me. Nothing that was advanced in their reply changes the points made in my initial letter.

Details

Circuit World, vol. 10 no. 4
Type: Research Article
ISSN: 0305-6120

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