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Article
Publication date: 19 October 2021

Tong Wang, Jing Di and Hongliang Zuo

In view of the defects of glued wood beams, a new composite member – reconstituted bamboo board reinforced glued wood beams is proposed to improve the bearing capacity of glued…

Abstract

Purpose

In view of the defects of glued wood beams, a new composite member – reconstituted bamboo board reinforced glued wood beams is proposed to improve the bearing capacity of glued wood beams.

Design/methodology/approach

The bending test studied the ordinary glulam beams and the reinforced glulam beams with different layer numbers and different layer thicknesses by comparing with six kinds of glulam beams strengthened with bamboo scrimber and one kind of ordinary glulam beams and used the method of third-point stepwise loading on the glulam beams strengthened with bamboo scrimber.

Findings

The bamboo scrimber improved the bending behavior of the ordinary glulam beams. The 10 mm bamboo scrimber layer can meet the requirements of the maximum ultimate bending capacity and minimize the defects. So 10 mm bamboo scrimber layer was the optimal thickness. During the loading process, the strain change of the normal section of the reconstituted bamboo board reinforced glued wood beam basically conforms to the plane section assumption.

Originality/value

The bending rigidities of the glulam beams strengthened with bamboo scrimber increased up to 28.25%, 8.53% and 76.67%, and the ultimate bending capacity increased from 83.44% to 99.34% with the increase of the bamboo scrimber plate layers (the replacement rate). The ultimate bending capacities and the bending rigidities of the glulam beams strengthened with bamboo scrimber increased to 52.32%∼60.18% and 90.07%∼99.34% with the changing of the bamboo scrimber thicknesses from 7.1 mm to 25 mm.

Details

International Journal of Structural Integrity, vol. 13 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 13 August 2018

Jiawei Wang, Guanhua Zhang, Jinliang Liu and Yanmin Jia

During service period, the bridge structures will be affected by the environment and load, so the carrying capacity will decline. The purpose of this paper is to research on the…

Abstract

Purpose

During service period, the bridge structures will be affected by the environment and load, so the carrying capacity will decline. The purpose of this paper is to research on the bearing capacity of bridge structures with time.

Design/methodology/approach

Destructive test and non-linear finite element analysis are carried out by utilizing two pretensioning prestressed concrete hollow slabs in service for 20 years; using the structural test deflection value to simulate the stiffness degradation of the service bridge and the finite element calculation results verify the accuracy of the calculation.

Findings

The flexural rigidity of the main beam when the test beam is destructed is degraded to approximately 20 percent of that before the test, which agrees well with the result of finite element analysis and indicates that the method of deducing the flexural rigidity of the structure according to the measured deflection value can effectively simulate the rigidity degradation law of the bridge in service. The crack resistance property of the test beam degrades obviously and the ultimate bearing capacity of the bending resistance does not degrade obviously.

Originality/value

The research results truly reflect the destruction process, destructive form, bearing capacity and rigidity degradation law of the old beam of the concrete bridge in service for 20 years and can provide technical basis for optimization design of newly built bridges of the same type and maintenance and reinforcement design of existing old bridges.

Details

International Journal of Structural Integrity, vol. 9 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 26 September 2019

Monica Malhotra, Vaishali Sahu, Amit Srivastava and Anil Kumar Misra

The purpose of this study is to investigate the effect of presence of buried flexible pipe on the bearing capacity of shallow footing. First, a model study is performed where…

Abstract

Purpose

The purpose of this study is to investigate the effect of presence of buried flexible pipe on the bearing capacity of shallow footing. First, a model study is performed where shallow footing model is tested for its load settlement behavior, with and without the existence of buried PVC pipe lying vertically below the base of the footing.

Design/methodology/approach

The experimental set-up consisted of a steel box filled with sand at two different relative density values [RD = 50 per cent (medium dense) and RD = 80 per cent (dense sand)] and vertical load was applied on the model footing through hydraulic jack and reaction frame arrangement connected with a proving ring. Test results are verified numerically using commercially available finite element code PLAXIS 2D. With due verification, a parametric study has been conducted, numerically, by varying the range of input parameters, such as unit weight, angle of internal friction, diameter of buried conduit and the Elastic modulus of the soil to assess the pre cent reduction in the capacity of the foundation soil because of the presence of underlying buried flexible pipe.

Findings

Results show that for each footing, there exists a critical depth below which the presence of the buried conduit has negligible influence on the footing performance. When the conduit is located above the critical depth, the bearing capacity of the footing varies with various factors, such as geotechnical parameters of soil and location and diameter of the buried conduit.

Originality/value

It is an original paper performed to assess the presence of buried flexible pipe on the bearing capacity of the shallow footing.

Details

Journal of Engineering, Design and Technology , vol. 18 no. 3
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 1 April 1962

H.L. WUNSCH

Bearings of either the rolling or sliding type form an integral part of most moving machinery and their lubrication has been the subject of much research. Until quite recently…

Abstract

Bearings of either the rolling or sliding type form an integral part of most moving machinery and their lubrication has been the subject of much research. Until quite recently, lubricants have generally taken the form of oil or grease and it is only in the last ten to fifteen years that the use of air in this field has really been considered. In many applications, in the nuclear power and missile field, for example, it has been found that conventional lubricants do not meet the demands of high temperature, radio‐active environments, etc., and this has stimulated research into the subject of air, or more generally, gas bearings.

Details

Industrial Lubrication and Tribology, vol. 14 no. 4
Type: Research Article
ISSN: 0036-8792

Article
Publication date: 4 July 2023

Yixing Ding, Yanmin Jia, Jiangyue Li, Huiming Li and Xiaobo Zhang

The purpose of this study is to investigate the effects of stud height, stud diameter, ultimate stress of stud and concrete strength on the static behaviour of studs in push-off…

Abstract

Purpose

The purpose of this study is to investigate the effects of stud height, stud diameter, ultimate stress of stud and concrete strength on the static behaviour of studs in push-off tests based on the ductile fracture theory.

Design/methodology/approach

Push-off tests of headed stud shear connectors with different heights and diameters used in concrete of various strengths were designed and implemented. A finite element model was established based on a ductile fracture criterion of ML15 cold-heading steel with stress triaxiality and Lode angle parameter. Based on the results of the parametric study of the numerical model, equations were proposed to evaluate the effect of stud height hs, stud area As, concrete strength fc and stud ultimate strength fsu used in concrete of various strengths on the static behaviour of studs.

Findings

The typical failure phenomenon observed among the test specimens was the fracture of the shank of studs. The microscopic images of the stud fracture surfaces and the verified finite element model indicate that the studs were fractured as a result of the combined action of tension and shear.

Originality/value

A new method for calculating ultimate load Pu and ultimate slip Su is proposed in this paper. In the method, Pu is linearly related to fsu0.2143, As0.7790, hs0.0974, fc0.2065. Su is linearly related to fsu1.078, As0.4681, hs(−0.3135), fc(−0.3480).

Details

International Journal of Structural Integrity, vol. 14 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 6 July 2022

Baocheng Liu, Jinliang Liu, Yanqian Wen, Qinglin Hu, Liang Liu and Shili Zhao

In this paper, to obtain shear and bending performance of carbon fiber-reinforced polymer (CFRP)-strengthened beams bonded by geopolymers, the effects of impregnated adhesive…

Abstract

Purpose

In this paper, to obtain shear and bending performance of carbon fiber-reinforced polymer (CFRP)-strengthened beams bonded by geopolymers, the effects of impregnated adhesive types, strengthened scheme, CFRP layer and pre-cracked width are investigated, and the performance of CFRP-strengthened beams is validated by the establishment of Finite Element Models (FEMs).

Design/methodology/approach

In this paper, static loading test and finite element analysis of epoxy-CFRP-strengthened (ECS) and geopolymer-CFRP-strengthened (GCS) were carried out, and the bearing capacity and stiffness were compared, the results show that GCS reinforced concrete (RC) beam is feasible and effective.

Findings

The bearing capacity, crack distribution and development, load–deflection curves of GCS RC beams with different pre-crack widths were investigated. The reinforcement effect of geopolymer achieves the same as epoxy, effectively improving the ultimate bearing capacity of the beam, with a maximum increase rate of 28.9%. The failure mode of CFRP is broken in the yield failure stage of GCS RC beam with reasonable strengthening form, and the utilization rate of CFRP is improved. CFRP-strengthened layers, pre-cracked widths significantly affect the mechanical properties, and deformation properties of the strengthened beams.

Originality/value

Compared with ECS RC beams, the bearing capacity and stiffness of GCS RC beams are similar to or even better, indicating that GCS RC beam is feasible and effective. It is a new method for CFRP-strengthened beams, which not only conforms to the concept of national ecological civilization construction, but also provides an economical, environmentally friendly and excellent performance solution for structural reinforcement.

Details

International Journal of Structural Integrity, vol. 13 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 5 September 2018

Ehsan Sadrossadat, Behnam Ghorbani, Rahimzadeh Oskooei and Mahdi Kaboutari

This study aims to examine the potential of two artificial intelligence (AI)-based algorithms, namely, adaptive neuro-fuzzy inference system (ANFIS) and gene expression…

Abstract

Purpose

This study aims to examine the potential of two artificial intelligence (AI)-based algorithms, namely, adaptive neuro-fuzzy inference system (ANFIS) and gene expression programming (GEP), for indirect estimation of the ultimate bearing capacity (qult) of rock foundations, which is a considerable civil and geotechnical engineering problem.

Design/methodology/approach

The input-processing-output procedures taking place in ANFIS and GEP are represented for developing predictive models. The great importance of simultaneously considering both qualitative and quantitative parameters for indirect estimation of qult is taken into account and explained. This issue can be considered as a remarkable merit of using AI-based approaches. Furthermore, the evaluation procedure of various models from both engineering and accuracy viewpoints is also demonstrated in this study.

Findings

A new and explicit formula generated by GEP is proposed for the estimation of the qult of rock foundations, which can be used for further engineering aims. It is also presented that although the ANFIS approach can predict the output with a high degree of accuracy, the obtained model might be a black-box. The results of model performance analyses confirm that ANFIS and GEP can be used as alternative and useful approaches over previous methods for modeling and prediction problems.

Originality/value

The superiorities and weaknesses of GEP and ANFIS techniques for the numerical analysis of engineering problems are expressed and the performance of their obtained models is compared to those provided by other approaches in the literature. The findings of this research provide the researchers with a better insight to using AI techniques for resolving complicated problems.

Article
Publication date: 20 August 2021

Pandimani, Markandeya Raju Ponnada and Yesuratnam Geddada

This paper aims to present nonlinear numerical simulations using the versatile finite element (FE) analysis tool ANSYS and theoretical analysis based on code provisions to assess…

Abstract

Purpose

This paper aims to present nonlinear numerical simulations using the versatile finite element (FE) analysis tool ANSYS and theoretical analysis based on code provisions to assess the load-carrying capacity of reinforced concrete (RC) beams under two-point monotonic static loadings.

Design/methodology/approach

Four quarter-size FE models with load and geometry symmetry conditions were constructed, the load-bearing capacity and associated mid-span deflections at critical points are verified against the full-scale experimental RC beams available in the literature. These developed FE models incorporated the tension stiffening effects and bond–slip behaviour. Theoretical analyses based on Indian standard code IS: 456–2000 and ACI 318–19 were also carried to verify the experimental and numerical predicted moments at critical loading points.

Findings

The load-deflection curves predicted through FE models exhibit closer corroboration with the experimental curves throughout the loading history. The contour plots for deflections, concrete principal stresses, reinforcement yield stresses are satisfactorily predicted by the FE models, which reveal the complete information of nonlinear behaviour of RC beams. The developed model well captured the initial and progressive crack patterns at each load increments.

Practical implications

The FE modelling is an efficient, valid and economical tool that is an alternative to the expensive experimental program and can be used to explore, analyse and fully understand the nonlinear response of RC beams under static loadings.

Originality/value

The ultimate moment capacity evaluated based on ACI 318–19 code provision show a better correlation with the experimental data as compared to the IS: 456–2000 code provision. The ultimate loads and associated centre-span deflections predicted by RN-2, RN-3, RB-12 and RB-16 FE model show a discrepancy of 1.66 and –0.49%, –4.68 and –0.60%, –9.38 and –14.53% and –4.37 and 4.21%, respectively, against the experimental results, which reveals that the developed ANSYS FE models predict consistent results and achieved a reasonable agreement with the experimental data.

Details

Journal of Engineering, Design and Technology , vol. 21 no. 4
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 20 January 2022

Pragyan Paramita Das, Vishwas Nandkishor Khatri, Rahul Doley, Rakesh Kumar Dutta and Jitendra Singh Yadav

This paper aims to estimate the bearing capacity of a surface strip and circular footings lying on layered sand using numerical limit analysis.

Abstract

Purpose

This paper aims to estimate the bearing capacity of a surface strip and circular footings lying on layered sand using numerical limit analysis.

Design/methodology/approach

Lower and upper bound limit analysis, as well as finite elements and second-order conic programming (SOCP), are used in this analysis. The yield criterion of Mohr-Coulomb is used to model soil behavior. Using this technique, stringent lower and upper bounds on ultimate bearing capacity can be achieved by assuming an associated flow law.

Findings

The obtained results indicate that the exact collapse load is typically being bracketed to within 6% about a mean of both the bounds. The obtained results are compared with the existing literature wherever applicable.

Originality/value

To the best of the authors’ knowledge, no study has used lower and upper bound limit analysis, as well as finite elements and SOCP, to estimate the bearing capacity of a surface strip and circular footings lying on layered sand.

Details

Journal of Engineering, Design and Technology , vol. 22 no. 2
Type: Research Article
ISSN: 1726-0531

Keywords

Article
Publication date: 22 May 2023

Pandimani

The ultimate capacity and ductility behavior of a reinforced concrete (RC) beam generally depends on its constituent material properties. This study aims to use ANSYS to…

Abstract

Purpose

The ultimate capacity and ductility behavior of a reinforced concrete (RC) beam generally depends on its constituent material properties. This study aims to use ANSYS to accentuate the nonlinear parametric finite element (FE) simulations of RC sections under monotonic loading.

Design/methodology/approach

The concrete matrix and steel reinforcement are the primary constituent materials of RC beams. The material properties such as tensile reinforcement area, tensile bars yield strength, concrete compressive strength and strain rate in tensile reinforcement at nominal strength have significantly influenced the ultimate response of RC beams. Therefore, these intensive parameters are considered in this study to ascertain their effect on the RC beam's ultimate behavior. The nonlinear response up to the ultimate load capacity and the crack evolutions of RC beams are predicted efficiently.

Findings

The parametric study reveals that increasing the tensile steel reinforcements (from Ast = 213–857 mm2) significantly improves the ultimate load capacity by 229% and yield deflections by 20%. However, it declines the ultimate deflection by 47% and ductility by 56% substantially. Varying the strain limit (?tn = 0.010–0.0015) of tensile reinforcement has proficiently increased the ultimate load-resisting capacity by 20%, whereas the ductility declined by 62%. When the concrete strength increases (from fck = 25–65 MPa), the cracking load increases profoundly by 51%, whereas the ultimate capacity has found an insignificant effect.

Originality/value

The load-deflection response plots extracted from the proposed numerical model exhibit satisfactory accuracy (less than 9% deviation) against the experimental curves available in the literature, which emphasizes the proficiency of the proposed FE model.

Details

Multidiscipline Modeling in Materials and Structures, vol. 19 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

11 – 20 of over 7000