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Article
Publication date: 4 January 2022

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The…

Abstract

Purpose

The partially prestressed concrete beam with unbonded tendon is still an active field of research because of the difficulty in analyzing and understanding its behavior. The finite-element (FE) simulation of such beams using numerical software is very scarce in the literature and therefore this study is taken to demonstrate the modeling aspects of unbonded partially prestressed concrete (UPPSC) beams. This study aims to present the three-dimensional (3-D) nonlinear FE simulations of UPPSC beams subjected to monotonic static loadings using the numerical analysis package ANSYS.

Design/methodology/approach

The sensitivity study is carried out with three different mesh densities to obtain the optimum elements that reflect on the load–deflection behavior of numerical models, and the model with optimum element density is used further to model all the UPPSC beams in this study. Three half-symmetry FE model is constructed in ANSYS parametric design language domain with proper boundary conditions at the symmetry plane and support to achieve the same response as that of the full-scale experimental beam available in the literature. The linear and nonlinear material behavior of prestressing tendon and conventional steel reinforcements, concrete and anchorage and loading plates are modeled using link180, solid65 and solid185 elements, respectively. The Newton–Raphson iteration method is used to solve the nonlinear solution of the FE models.

Findings

The evolution of concrete cracking at critical loadings, yielding of nonprestressed steel reinforcements, stress increment in the prestressing tendon, stresses in concrete elements and the complete load–deflection behavior of the UPPSC beams are well predicted by the proposed FE model. The maximum discrepancy of ultimate moments and deflections of the validated FE models exhibit 13% and −5%, respectively, in comparison with the experimental results.

Practical implications

The FE analysis of UPPSC beams is done using ANSYS software, which is a versatile tool in contrast to the experimental testing to study the stress increments in the unbonded tendons and assess the complete nonlinear response of partially prestressed concrete beams. The validated numerical model and the techniques presented in this study can be readily used to explore the parametric analysis of UPPSC beams.

Originality/value

The developed model is capable of predicting the strength and nonlinear behavior of UPPSC beams with reasonable accuracy. The load–deflection plot captured by the FE model is corroborated with the experimental data existing in the literature and the FE results exhibit good agreement against the experimentally tested beams, which expresses the practicability of using FE analysis for the nonlinear response of UPPSC beams using ANSYS software.

Details

Journal of Engineering, Design and Technology , vol. 22 no. 1
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 3 July 2017

Pengzhen Lu, Hua Shao and Jian Ting Cheng

The purpose of this paper is to develop a simplified optimization calculation method to assess cable force of self-anchored suspension bridge based on optimization theories.

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Abstract

Purpose

The purpose of this paper is to develop a simplified optimization calculation method to assess cable force of self-anchored suspension bridge based on optimization theories.

Design/methodology/approach

A simplified analysis method construction using Matlab is developed, which is then compared with the optimization method that considers the main cable’s geometric nonlinearity with software ANSYS in an actual bridge calculation.

Findings

This contrast proves the weak coherence and the adjacently interaction theory unreasonable and its limitation.

Originality/value

This paper analyzes the calculation method to assess cable force of a self-anchored suspension bridge and its application effect.

Details

Engineering Computations, vol. 34 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 August 1997

Zeljana Nikolic and Ante Mihanovic

Presents a non‐linear numerical model for the computations of post‐tensioned plane structures. Generally curved prestressing tendons and reinforcing bars are embedded into the…

1038

Abstract

Presents a non‐linear numerical model for the computations of post‐tensioned plane structures. Generally curved prestressing tendons and reinforcing bars are embedded into the concrete and they are modelled independently of the concrete mesh using one‐dimensional curvilinear elements. Among the losses which influence the decrease in the prestress force, it is possible to compute the losses caused by friction between tendons and the concrete, the losses which result from the concrete deformation and the losses in the anchorage zone. The computation for post‐tensioned structures is organized in phases: the phase preceding prestressing (Phase I), the prestressing phase (Phase II) and the phase following prestressing (Phase III). The load is applied incrementally until failure. The model is tested on a number of examples.

Details

Engineering Computations, vol. 14 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 July 2005

Pavao Marović, Željana Nikolić and Mirela Galić

To provide an insight in one relatively simple and efficient numerical model for analysing reinforced and prestressed concrete structures, and to raise a discussion leading to the…

Abstract

Purpose

To provide an insight in one relatively simple and efficient numerical model for analysing reinforced and prestressed concrete structures, and to raise a discussion leading to the creation of one universal and robust 3D algorithm.

Design/methodology/approach

A new numerical model for analysing reinforced and prestressed concrete structures is developed and main theoretical details are described to aid the understandings. The approach is clear, easily readable and the body of the text is divided into logical sections starting from theoretical explanations ending in the large number of different practical examples.

Findings

Provides information about developing new and relatively simple numerical model for analysing reinforced and prestressed concrete structures, indicating what can be improved. Recognises the lack of knowing real behaviour of 3D concrete and starts a discussion on it.

Research limitations/implications

The knowledge of the 2D and especially 3D concrete behaviour is still poor and the concrete model developers use many simplifications. So, many new experiments should be performed and better numerical models should be developed. There is large area for researchers but having in mind that experiments are very expensive.

Practical implications

Obtained results of the 3D analysis of reinforced and prestressed concrete structures can stand as a benchmark for future researches in this field especially to the young researchers and concrete model developers.

Originality/value

This paper presents new and very simple numerical model for analysing reinforced and prestressed concrete structures. Paper could be very valuable to the researchers in this field as a benchmark for their analyses.

Details

Engineering Computations, vol. 22 no. 5/6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 3 February 2012

R. Kalina, H. Wheat, S. MacLean and J. Breen

In order to complement a large-scale long-term investigation of prestressing strand types for post-tensionsing of bridges, passive and active electrochemical tests were carried…

Abstract

In order to complement a large-scale long-term investigation of prestressing strand types for post-tensionsing of bridges, passive and active electrochemical tests were carried out on bare and grouted specimens exposed to salt water conditions as a function of time. The materials tested included seven-wire strands made of hot dip galvanized or zinc coated steel, stainless steel, stainless clad steel, copper clad steel, flow-filled epoxy coated steel and conventional steel as control. Based on corrosion potentials, polarization resistance tests, potentiodynamic tests, weight loss, and visual observations, epoxy coated strands, stainless and stainless clad strands were identified as possible alternatives to conventional steel that might help to minimize corrosion.

Details

World Journal of Engineering, vol. 9 no. 1
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 16 October 2007

H. Al Nageim and D. Pountney

The aim is to present findings of a theoretical analysis for optimal design of a concrete trough for a new lightweight low‐profile rail track system.

Abstract

Purpose

The aim is to present findings of a theoretical analysis for optimal design of a concrete trough for a new lightweight low‐profile rail track system.

Design/methodology/approach

A non‐linear numerical optimisation technique is adopted to predict the minimum area of a pre‐tensioned pre‐stressed trough section satisfying the serviceability and ultimate limit states as per British Standard BS 8110 for critical loading and boundary conditions.

Findings

An optimum concrete trough section is calculated to carry all possible load combinations expected during the design life of the track. The performance of the rail, elastomeric pad and track base were found to be satisfactory under the same critical loading and boundary conditions.

Originality/value

The theoretical analysis gives a valuable insight into system parameter values that can optimise design performance and cost. However, these optimal design features now need to be tested experimentally.

Details

Construction Innovation, vol. 7 no. 4
Type: Research Article
ISSN: 1471-4175

Keywords

Article
Publication date: 22 June 2017

Jean-Marc Franssen and Thomas Gernay

This paper aims to describe the theoretical background and main hypotheses at the basis of SAFIR®, a nonlinear finite element software for modeling structures in fire. The paper…

2185

Abstract

Purpose

This paper aims to describe the theoretical background and main hypotheses at the basis of SAFIR®, a nonlinear finite element software for modeling structures in fire. The paper also explains how to use the software at its full extent. The discussed numerical modeling principles can be applied with other similar software.

Design/methodology/approach

Following a general overview of the organization of the software, the thermal analysis part is explained, with the basic equations and the different possibilities to apply thermal boundary conditions (compartment fire, localized fire, etc.). Next, the mechanical analysis part is detailed, including the time integration procedures and the different types of finite elements: beam, truss, shell, spring and solid. Finally, the material laws are described. The software capabilities and limitations are discussed throughout the paper.

Findings

By accommodating multiple types of finite elements and materials, by allowing the user to consider virtually any section type and to input the fire attack in multiple forms, the software SAFIR® is a comprehensive tool for investigating the behavior of structures in the fire situation. Meanwhile, being developed exclusively for its well-defined field of application, it remains relatively easy to use.

Originality value

The paper will improve the knowledge of readers (researchers, designers and authorities) about numerical modeling used in structural fire engineering in general and the capabilities of a particular software largely used in the fire engineering community.

Details

Journal of Structural Fire Engineering, vol. 8 no. 3
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 12 December 2023

T.M. Jeyashree and P.R. Kannan Rajkumar

This study focused on identifying critical factors governing the fire response of prestressed hollow-core slabs. The hollow-core slabs used as flooring units can be subjected to…

Abstract

Purpose

This study focused on identifying critical factors governing the fire response of prestressed hollow-core slabs. The hollow-core slabs used as flooring units can be subjected to elevated temperatures during a fire. The fire response of prestressed hollow-core slabs is required to develop slabs with greater fire endurance. The present study aims to determine the extent to which the hollow-core slab can sustain load during a fire without undergoing progressive collapse under extreme fire and heating scenarios.

Design/methodology/approach

A finite element model was generated to predict the fire response of prestressed hollow core slabs under elevated temperatures. The accuracy of the model was predicted by examining thermal and structural responses through coupled temperature displacement analysis. A sensitivity analysis was performed to study the effects of concrete properties on prediction of system response. A parametric study was conducted by varying the thickness of the slab, fire and heating scenarios.

Findings

Thermal conductivity and specific heat of concrete were determined as sensitive parameters. The thickness of the slab was identified as a critical factor at a higher load level. Asymmetric heating of the slab resulted in higher fire resistance compared with symmetric heating.

Originality/value

This is the first study focused on studying the effect of modeling uncertainties on the system response by sensitivity analysis under elevated temperatures. The developed model with a parametric study helps in identifying critical factors for design purposes.

Details

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

Keywords

Article
Publication date: 1 January 1984

W.S. Doyle and A.R. Lloyd

The finite element analysis capabilities of DART and the design routines for the computerized design in accordance with CP 110 and BS 5337 are briefly described. The DART program…

Abstract

The finite element analysis capabilities of DART and the design routines for the computerized design in accordance with CP 110 and BS 5337 are briefly described. The DART program is used to compare some reservoir roof systems including a novel floated dome. Temperature effects on reservoirs can appear to yield severe stresses, but do they? The DART program is used for the design of non‐axisymmetric loaded structures and examples are given of wind loads on water towers and chimneys. A simple procedure has been incorporated into DART to allow for soil—structure interaction. The DART program can print out reinforcing or prestressing requirements. An elementary cost study has been made on reservoir walls to compare the relevant merits of the two methods of design. A facility has been incorporated into the DART program to find the optimum shape of reservoirs and water towers for a given set of construction costs. The Dynamic Programming method has been used for this purpose. Natural frequencies and mode shapes can be determined by the DART program using the Sturm sequence property and inverse iteration respectively.

Details

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

Article
Publication date: 14 March 2016

Ya Wei, Francis T.K. Au, Jing Li and Neil C.M. Tsang

This paper aims to understand the structural fire performance of two-way post-tensioned flat slabs, particularly their deformations and load-carrying mechanisms in fire, and to…

Abstract

Purpose

This paper aims to understand the structural fire performance of two-way post-tensioned flat slabs, particularly their deformations and load-carrying mechanisms in fire, and to explore the behaviour of post-tensioned high-strength self-compacting concrete flat slabs with unbonded tendons in fire.

Design/methodology/approach

Four tests of post-tensioned high-strength self-compacting concrete flat slabs were conducted under fire conditions. Numerical modelling using the commercial package ABAQUS was conducted to help interpret the test results.

Findings

Two of the specimens with lower moisture contents demonstrated excellent fire resistance performance, while the others with slightly higher moisture contents experienced severe concrete spalling.

Originality/value

The test results were discussed in respect of thermal profiles, deflections, crack patterns and concrete spalling. The performance of post-tensioned high-strength self-compacting concrete flat slabs with unbonded tendons under fire conditions was better understood.

Details

Journal of Structural Fire Engineering, vol. 7 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

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