Pub Date : 2021-09-01DOI: 10.18057/ijasc.2021.17.3.2
Ankur Kumar, Krishanu Roy, Asraf Uzzaman, James B. P. Lim
This paper presents the results of a finite element investigation on cold-formed steel (CFS) channel sections with circular web holes under end-two-flange (ETF) loading condition and subjected to elevated temperatures. The stress strain curve for G250 CFS with 1.95 mm thickness at elevated temperatures was taken from Kankanamge and Mahendran and the temperatures were considered up to 700 oC. To analyse the effect of web hole size and bearing length on the strength of such sections at elevated temperatures, a parametric study involving a total of 288 FE models was performed. The parametric study results were then used to assess the applicability of the strength reduction factor equation presented by Uzzaman et al. for CFS channel-sections with web holes under ETF loading from ambient temperature to elevated temperatures. It is shown that the reduction factor equation is safe and reliable at elevated temperatures.
{"title":"FINITE ELEMENT ANALYSIS OF UNFASTENED COLD-FORMED STEEL CHANNEL SECTIONS WITH WEB HOLES UNDER END-TWO-FLANGE LOADING AT ELEVATED TEMPERATURES","authors":"Ankur Kumar, Krishanu Roy, Asraf Uzzaman, James B. P. Lim","doi":"10.18057/ijasc.2021.17.3.2","DOIUrl":"https://doi.org/10.18057/ijasc.2021.17.3.2","url":null,"abstract":"This paper presents the results of a finite element investigation on cold-formed steel (CFS) channel sections with circular web holes under end-two-flange (ETF) loading condition and subjected to elevated temperatures. The stress strain curve for G250 CFS with 1.95 mm thickness at elevated temperatures was taken from Kankanamge and Mahendran and the temperatures were considered up to 700 oC. To analyse the effect of web hole size and bearing length on the strength of such sections at elevated temperatures, a parametric study involving a total of 288 FE models was performed. The parametric study results were then used to assess the applicability of the strength reduction factor equation presented by Uzzaman et al. for CFS channel-sections with web holes under ETF loading from ambient temperature to elevated temperatures. It is shown that the reduction factor equation is safe and reliable at elevated temperatures.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"17 1","pages":"231-242"},"PeriodicalIF":1.7,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41552213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.18057/ijasc.2021.17.1.9
Jui-Lin Peng, Shu Hong Wang, Chung-Sheng Wang, Judy P. Yang
A scaffolding system is a temporary structure that is commonly adopted on construction sites. As steel scaffolds are modular members manufactured with fixed dimensions, the total height of a scaffolding system seldom fits the headroom of a building when scaffolds are set up in multiple stories. This results in a difference in elevation, i.e. gap, between the top of the scaffolding system and the ceiling slab. In addition, scaffold configurations may need to be adjusted if the interior of a building has inclined planes on the ceiling slab or stairs on the ground. This study shows that the gap between the scaffold and the ceiling slab can be eliminated by altering the lengths of adjustable base jacks or adjustable U-head jacks. When the ceiling slab is inclined, it is suggested that a combined system of scaffolds with wooden shores of different lengths should be installed in the out-of-plane direction of the scaffold unit. This system can also be used when the ceiling slab is inclined and the ground has a difference in elevation (e.g., stairs) in a building. By using the second-order elastic analysis with semi- rigid joints, the load-bearing capacity and failure model are found to be very close to those obtained in the loading tests using various scaffold configurations. In the loading tests for reused scaffolds, the lower bound of the load-bearing capacity of the scaffolding systems can be obtained by applying a subsequent load on the scaffolding systems, which are commonly adopted on the construction sites. The strength reduction factor ( ) of these scaffolding systems installed by reused scaffolds can be obtained by calculating the mean value and standard deviation, which can serve as a reference for the strength design of scaffolding systems with different safety requirements. the stability behavior of various scaffolding systems, an inclined ceiling slab, adjustable U-head jacks, base jacks lengths, an difference on the ground second-order semi-rigid
{"title":"STABILITY STUDY ON SCAFFOLDS WITH INCLINED SURFACES AND EXTENDED JACK BASES IN CONSTRUCTION","authors":"Jui-Lin Peng, Shu Hong Wang, Chung-Sheng Wang, Judy P. Yang","doi":"10.18057/ijasc.2021.17.1.9","DOIUrl":"https://doi.org/10.18057/ijasc.2021.17.1.9","url":null,"abstract":"A scaffolding system is a temporary structure that is commonly adopted on construction sites. As steel scaffolds are modular members manufactured with fixed dimensions, the total height of a scaffolding system seldom fits the headroom of a building when scaffolds are set up in multiple stories. This results in a difference in elevation, i.e. gap, between the top of the scaffolding system and the ceiling slab. In addition, scaffold configurations may need to be adjusted if the interior of a building has inclined planes on the ceiling slab or stairs on the ground. This study shows that the gap between the scaffold and the ceiling slab can be eliminated by altering the lengths of adjustable base jacks or adjustable U-head jacks. When the ceiling slab is inclined, it is suggested that a combined system of scaffolds with wooden shores of different lengths should be installed in the out-of-plane direction of the scaffold unit. This system can also be used when the ceiling slab is inclined and the ground has a difference in elevation (e.g., stairs) in a building. By using the second-order elastic analysis with semi- rigid joints, the load-bearing capacity and failure model are found to be very close to those obtained in the loading tests using various scaffold configurations. In the loading tests for reused scaffolds, the lower bound of the load-bearing capacity of the scaffolding systems can be obtained by applying a subsequent load on the scaffolding systems, which are commonly adopted on the construction sites. The strength reduction factor ( ) of these scaffolding systems installed by reused scaffolds can be obtained by calculating the mean value and standard deviation, which can serve as a reference for the strength design of scaffolding systems with different safety requirements. the stability behavior of various scaffolding systems, an inclined ceiling slab, adjustable U-head jacks, base jacks lengths, an difference on the ground second-order semi-rigid","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"17 1","pages":"73-83"},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67607085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.18057/IJASC.2021.17.2.10
Jiahong Ning, Siwei Liu, Jianhong Wan, Wei Huang
Subsea pipeline is the critical component in the offshore systems for transporting oil and gas from resource sites to ports. Its structural failure will be a disaster of heavily polluting the environment leading to unpredictable losses. The mediums inside subsea pipelines are conventionally heated in service for easier transporting after increasing fluidity, resulting in accumulative thermal expansion of the pipeline to induce thermal expansion, triggering upheaval buckling. It is crucial when designing subsea pipelines but always challenging to evaluate rigorously because of the complexities in such consideration. A pipeline might length for miles, while the numerical analysis model using conventional solid finite elements is huge in computational expense, making the successful analysis very time-consuming. This research innovatively develops a new line element, namely the pipeline element, featuring the explicit considerations of soil -pipe interactions and thermal expansion. This element is numerically efficient by eliminating modeling buried soils. The element derivation procedure is elaborated with details, while a Newton-Raphson typed numerical analysis procedure is proposed for nonlinear analysis of pipelines subjected to thermal expansion. An Updated-Lagrangian description is employed for facilitating large deflections. Three groups of examples are provided to demonstrate the numerical robustness of the proposed method. Finally, a case study is given to identify the vital influential factors to the thermal upheaval buckling of pipelines. Received: Revised: Accepted: 11 April 2021 21 May 2021 21 May 2021
{"title":"Line-element formulation for upheaval buckling analysis of buried subsea pipelines due to thermal expansion","authors":"Jiahong Ning, Siwei Liu, Jianhong Wan, Wei Huang","doi":"10.18057/IJASC.2021.17.2.10","DOIUrl":"https://doi.org/10.18057/IJASC.2021.17.2.10","url":null,"abstract":"Subsea pipeline is the critical component in the offshore systems for transporting oil and gas from resource sites to ports. Its structural failure will be a disaster of heavily polluting the environment leading to unpredictable losses. The mediums inside subsea pipelines are conventionally heated in service for easier transporting after increasing fluidity, resulting in accumulative thermal expansion of the pipeline to induce thermal expansion, triggering upheaval buckling. It is crucial when designing subsea pipelines but always challenging to evaluate rigorously because of the complexities in such consideration. A pipeline might length for miles, while the numerical analysis model using conventional solid finite elements is huge in computational expense, making the successful analysis very time-consuming. This research innovatively develops a new line element, namely the pipeline element, featuring the explicit considerations of soil -pipe interactions and thermal expansion. This element is numerically efficient by eliminating modeling buried soils. The element derivation procedure is elaborated with details, while a Newton-Raphson typed numerical analysis procedure is proposed for nonlinear analysis of pipelines subjected to thermal expansion. An Updated-Lagrangian description is employed for facilitating large deflections. Three groups of examples are provided to demonstrate the numerical robustness of the proposed method. Finally, a case study is given to identify the vital influential factors to the thermal upheaval buckling of pipelines. Received: Revised: Accepted: 11 April 2021 21 May 2021 21 May 2021","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"17 1","pages":"210-220"},"PeriodicalIF":1.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67607419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.18057/ijasc.2020.16.4.8
Weihang Ouyang, Yi Yang, Jianhong Wan, Siwei Liu
Comparing to other supporting pile walls, steel sheet piles with a lower flexural rigidity have a more obvious and significant second-order effect with the large deformation. Also, the nonlinear Soil-Structure Interaction (SSI) can highly influence the efficiency and accuracy of the deformation and buckling of the steel sheet pile. Currently, some empirical methods with linear assumptions and the discrete spring element method are always used for the design of steel sheet piles in practical engineering. However, these methods are normally inaccurate or inefficient in considering the nonlinear SSI and the second-order effect. In this paper, a new line element, named pile element, is applied to analyze the structural behaviors of the steel sheet pile. In this new element, the soil resistance and pressure surrounding the pile as well as the pile shaft resistance are all integrated into the element formulation to simulate the nonlinear SSI. The Gauss-Legendre method is innovatively introduced to elaborate the realistic soil pressure distribution. For reducing the nonlinear iterations and numerical errors from the buckling behavior, the proposed numerical method and Updated-Lagrangian method will be integrated within a Newton-Raphson typed approach. Finally, several examples are given for validating the accuracy and efficiency of the developed pile element with the consideration of the realistic soil pressures. It can be found that the developed pile element has a significant advantage in simulating steel sheet piles.
{"title":"SECOND-ORDER ANALYSIS OF STEEL SHEET PILES BY PILE ELEMENT CONSIDERING NONLINEAR SOIL-STRUCTURE INTERACTIONS","authors":"Weihang Ouyang, Yi Yang, Jianhong Wan, Siwei Liu","doi":"10.18057/ijasc.2020.16.4.8","DOIUrl":"https://doi.org/10.18057/ijasc.2020.16.4.8","url":null,"abstract":"Comparing to other supporting pile walls, steel sheet piles with a lower flexural rigidity have a more obvious and significant second-order effect with the large deformation. Also, the nonlinear Soil-Structure Interaction (SSI) can highly influence the efficiency and accuracy of the deformation and buckling of the steel sheet pile. Currently, some empirical methods with linear assumptions and the discrete spring element method are always used for the design of steel sheet piles in practical engineering. However, these methods are normally inaccurate or inefficient in considering the nonlinear SSI and the second-order effect. In this paper, a new line element, named pile element, is applied to analyze the structural behaviors of the steel sheet pile. In this new element, the soil resistance and pressure surrounding the pile as well as the pile shaft resistance are all integrated into the element formulation to simulate the nonlinear SSI. The Gauss-Legendre method is innovatively introduced to elaborate the realistic soil pressure distribution. For reducing the nonlinear iterations and numerical errors from the buckling behavior, the proposed numerical method and Updated-Lagrangian method will be integrated within a Newton-Raphson typed approach. Finally, several examples are given for validating the accuracy and efficiency of the developed pile element with the consideration of the realistic soil pressures. It can be found that the developed pile element has a significant advantage in simulating steel sheet piles.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"16 1","pages":"354-362"},"PeriodicalIF":1.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44104300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.18057/ijasc.2020.16.4.4
C. Gong, Z. Hou, G. Cheng, Gang Wang, Y. Chen
A new composite slim floor system with voided RC slab is proposed, where the precast RC slab is used as the structural component as well as the permanent formwork, with the large voids achieved by light-weight fillers introduced to reduce the slab weight. The overlapping rebars pass through the web openings of steel beam, thus enhancing the interaction between the RC slab and steel beam. As a pilot study of the proposed floor system, the bending behavior of the new composite slim beam was investigated experimentally on four specimens. The full interaction between the RC slab and steel beam is demonstrated by the test and finite element analysis results. In addition, a calculation method for bending capacity is proposed. Biaxial-hollow slab; Asymmetric steel beam; Bending capacity.
{"title":"BENDING CAPACITY OF BIAXIAL-HOLLOW RC SLAB WITH ASYMMETRIC STEEL BEAMS","authors":"C. Gong, Z. Hou, G. Cheng, Gang Wang, Y. Chen","doi":"10.18057/ijasc.2020.16.4.4","DOIUrl":"https://doi.org/10.18057/ijasc.2020.16.4.4","url":null,"abstract":"A new composite slim floor system with voided RC slab is proposed, where the precast RC slab is used as the structural component as well as the permanent formwork, with the large voids achieved by light-weight fillers introduced to reduce the slab weight. The overlapping rebars pass through the web openings of steel beam, thus enhancing the interaction between the RC slab and steel beam. As a pilot study of the proposed floor system, the bending behavior of the new composite slim beam was investigated experimentally on four specimens. The full interaction between the RC slab and steel beam is demonstrated by the test and finite element analysis results. In addition, a calculation method for bending capacity is proposed. Biaxial-hollow slab; Asymmetric steel beam; Bending capacity.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"16 1","pages":"321-327"},"PeriodicalIF":1.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46842212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.18057/ijasc.2019.15.4.2
A. Tran, Lars Bernspång, M. Veljković, C. Rebelo, L. Silva
This paper describes a study of the S650 high strength steel material properties including the effect of cold -formed angle. Coupon specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160° and 180°) and different thicknesses (4 mm and 6 mm) were examined. Relationships between cold-formed angle and yield stress as well as tensile stress of the material were determined, based on the tensile coupon test results. Yield and tensile stresses assessed by consid ering the influence of the cold-formed angles were compared with those without considering this influence. Analyses revealed that both yield and tensile stresses decreased with increasing cold-formed angle. Ductile-damage material models available in the finite element analysis software ABAQUS were used to simulate tensile coupon tests. The experimental and numerical results showed good agreements. Received: Revised: Accepted: 19 March 2018 20 April 2019 05 May 2019
{"title":"INFLUENCE OF COLD-FORMED ANGLE ON HIGH STRENGTH STEEL MATERIAL PROPERTIES","authors":"A. Tran, Lars Bernspång, M. Veljković, C. Rebelo, L. Silva","doi":"10.18057/ijasc.2019.15.4.2","DOIUrl":"https://doi.org/10.18057/ijasc.2019.15.4.2","url":null,"abstract":"This paper describes a study of the S650 high strength steel material properties including the effect of cold -formed angle. Coupon specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160° and 180°) and different thicknesses (4 mm and 6 mm) were examined. Relationships between cold-formed angle and yield stress as well as tensile stress of the material were determined, based on the tensile coupon test results. Yield and tensile stresses assessed by consid ering the influence of the cold-formed angles were compared with those without considering this influence. Analyses revealed that both yield and tensile stresses decreased with increasing cold-formed angle. Ductile-damage material models available in the finite element analysis software ABAQUS were used to simulate tensile coupon tests. The experimental and numerical results showed good agreements. Received: Revised: Accepted: 19 March 2018 20 April 2019 05 May 2019","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"1 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46438910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-07DOI: 10.18057/ijasc.2019.15.3.4
A. Tran, Lars Bernspång, M. Veljković, C. Rebelo, L. Silva
This paper describes a study of the behaviour of cold-formed high strength steel angles. Thirty-six specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160°, and 170°) and different thicknesses (4 mm and 6 mm) were considered. The initial geometric imperfections of the specimens were determined using the 3D laser scanning method. The magnitudes of these geometric imperfections for torsional and torsional-flexural buckling and flexural buckling analyses were proposed. The commercial finite element analysis (FEA) programme ABAQUS with shell elements S4R was used for finite element analyses. Different material strengths in corner and flat parts along with different proof stresses (0.2%, 0.01%, and 0.006%) were considered in the numerical models. The experimental and FEA results showed good agreement. Influence of cold-formed angle on non-dimensional slenderness and reduction factor curves of the 4 mm thick columns with 90° and 120° cold-formed angles was analysed.
{"title":"RESISTANCE OF COLD FORMED HIGH STRENGTH STEEL ANGLES","authors":"A. Tran, Lars Bernspång, M. Veljković, C. Rebelo, L. Silva","doi":"10.18057/ijasc.2019.15.3.4","DOIUrl":"https://doi.org/10.18057/ijasc.2019.15.3.4","url":null,"abstract":"This paper describes a study of the behaviour of cold-formed high strength steel angles. Thirty-six specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160°, and 170°) and different thicknesses (4 mm and 6 mm) were considered. The initial geometric imperfections of the specimens were determined using the 3D laser scanning method. The magnitudes of these geometric imperfections for torsional and torsional-flexural buckling and flexural buckling analyses were proposed. The commercial finite element analysis (FEA) programme ABAQUS with shell elements S4R was used for finite element analyses. Different material strengths in corner and flat parts along with different proof stresses (0.2%, 0.01%, and 0.006%) were considered in the numerical models. The experimental and FEA results showed good agreement. Influence of cold-formed angle on non-dimensional slenderness and reduction factor curves of the 4 mm thick columns with 90° and 120° cold-formed angles was analysed.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"15 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43206528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-30DOI: 10.18057/IJASC.2019.15.2.6
S. Gunalan, M. Mahendran
Cold-formed steel members are becoming increasingly popular in the building industry due to their superior strength to weight ratio and ease of fabrication as opposed to hot-rolled steel members. However, they are susceptible to various buckling modes at stresses below the yield stress of the member because of their relatively high width-to-thickness ratio. Web crippling is one of the failure modes that occurs in steel channel sections under transverse concentrated loads or reactions. Recently a test method has been proposed by AISI to obtain the web crippling capacities under both one-flange and two-flange load cases. Using this test method 21 tests were conducted in this research to investigate the web crippling behaviour and strengths of an unlipped channel section with stocky webs known as DuraGal Channels under end-one-flange (EOF) and interior one-flange (IOF) load cases. DuraGal channels with different web slenderness and bearing lengths were tested with their flanges unfastened to supports. In this research the suitability of the currently available design rules for unlipped channels subject to web crippling under one flange load cases was investigated, and suitable modifications were proposed where necessary. This paper presents the details of this experimental study and the results.
{"title":"EXPERIMENTAL STUDY OF UNLIPPED CHANNEL BEAMS SUBJECT TO WEB CRIPPLING UNDER ONE FLANGE LOAD CASES","authors":"S. Gunalan, M. Mahendran","doi":"10.18057/IJASC.2019.15.2.6","DOIUrl":"https://doi.org/10.18057/IJASC.2019.15.2.6","url":null,"abstract":"Cold-formed steel members are becoming increasingly popular in the building industry due to their superior strength to weight ratio and ease of fabrication as opposed to hot-rolled steel members. However, they are susceptible to various buckling modes at stresses below the yield stress of the member because of their relatively high width-to-thickness ratio. Web crippling is one of the failure modes that occurs in steel channel sections under transverse concentrated loads or reactions. Recently a test method has been proposed by AISI to obtain the web crippling capacities under both one-flange and two-flange load cases. Using this test method 21 tests were conducted in this research to investigate the web crippling behaviour and strengths of an unlipped channel section with stocky webs known as DuraGal Channels under end-one-flange (EOF) and interior one-flange (IOF) load cases. DuraGal channels with different web slenderness and bearing lengths were tested with their flanges unfastened to supports. In this research the suitability of the currently available design rules for unlipped channels subject to web crippling under one flange load cases was investigated, and suitable modifications were proposed where necessary. This paper presents the details of this experimental study and the results.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"15 1","pages":"165-172"},"PeriodicalIF":1.7,"publicationDate":"2019-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46808505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.18057/IJASC.2018.14.4
J. K. Hsiao, S. Shrestha
: When a tension load is transmitted to some, but not all of the cross-sectional elements of a tension member, the tensile force is not uniformly distributed over the cross-sectional area of the tension member. The non-uniform stress distribution in the tension member is commonly referred to as the out-of-plane shear lag effect. The unequal-length longitudinal welds and the in-plane shear lag effect, however, are not addressed by the current American Institute of Steel Construction (AISC) Specification for the determination of the shear lag factors for tension members other than plates and Hollow Structural Sections (HSS). The purpose of this work is to propose a procedure for the computation of shear lag factors accounting for combined in-plane and out-of-plane shear lag effects on unequal-length longitudinal welded angles. The finite element method using three-dimensional solid elements and nonlinear static analyses accounting for combined material and geometric nonlinearities are conducted in this work to verify the accuracy of the proposed procedure.
{"title":"Shear Lag Factors for Tension Angles with Unequal-Length Longitudinal Welds","authors":"J. K. Hsiao, S. Shrestha","doi":"10.18057/IJASC.2018.14.4","DOIUrl":"https://doi.org/10.18057/IJASC.2018.14.4","url":null,"abstract":": When a tension load is transmitted to some, but not all of the cross-sectional elements of a tension member, the tensile force is not uniformly distributed over the cross-sectional area of the tension member. The non-uniform stress distribution in the tension member is commonly referred to as the out-of-plane shear lag effect. The unequal-length longitudinal welds and the in-plane shear lag effect, however, are not addressed by the current American Institute of Steel Construction (AISC) Specification for the determination of the shear lag factors for tension members other than plates and Hollow Structural Sections (HSS). The purpose of this work is to propose a procedure for the computation of shear lag factors accounting for combined in-plane and out-of-plane shear lag effects on unequal-length longitudinal welded angles. The finite element method using three-dimensional solid elements and nonlinear static analyses accounting for combined material and geometric nonlinearities are conducted in this work to verify the accuracy of the proposed procedure.","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"14 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67607145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.18057/ijasc.2019.15.2.5
O. Masri, E. Lui
Residual stresses and geometrical imperfections are important factors that affect the inelastic lateral-torsional buckling (LTB) capacity of flexural members. In this paper, the influence of the magnitudes of residual stresses and initial geometrical imperfections in the form of member out-of-straightness on the flexural resistance of steel delta girders (SDG) is investigated. Based on test data reported for welded plates and monosymmetric welded I -sections, a residual stress pattern for SDG is proposed. Six different combinations of residual stress and geometrical imperfection magnitudes are then used in a finite element simulation study of a series of SDG under uniform bending and simply-supported boundary conditions. The flexural resistance curves computed for these SDG are compared with one another to demonstrate that both residual stresses and initial member out-of-straightness have a noticeable influence on the moment capacity of SDG, especially in the inelastic LTB region. These curves are also compared against the flexural strength equations provided in the current AISC specifications. The comparison reveals that the AISC equations often over-predict the flexural strength of SDG. An SDG flexural strength reduction factor is then proposed to allow for the design of these SDG using the AISC design equations. Received: Revised: Accepted: 23 December 2017 26 July 2018 12 August 2018
{"title":"INFLUENCE OF IMPERFECTIONS ON THE FLEXURAL RESISTANCE OF STEEL DELTA GIRDERS","authors":"O. Masri, E. Lui","doi":"10.18057/ijasc.2019.15.2.5","DOIUrl":"https://doi.org/10.18057/ijasc.2019.15.2.5","url":null,"abstract":"Residual stresses and geometrical imperfections are important factors that affect the inelastic lateral-torsional buckling (LTB) capacity of flexural members. In this paper, the influence of the magnitudes of residual stresses and initial geometrical imperfections in the form of member out-of-straightness on the flexural resistance of steel delta girders (SDG) is investigated. Based on test data reported for welded plates and monosymmetric welded I -sections, a residual stress pattern for SDG is proposed. Six different combinations of residual stress and geometrical imperfection magnitudes are then used in a finite element simulation study of a series of SDG under uniform bending and simply-supported boundary conditions. The flexural resistance curves computed for these SDG are compared with one another to demonstrate that both residual stresses and initial member out-of-straightness have a noticeable influence on the moment capacity of SDG, especially in the inelastic LTB region. These curves are also compared against the flexural strength equations provided in the current AISC specifications. The comparison reveals that the AISC equations often over-predict the flexural strength of SDG. An SDG flexural strength reduction factor is then proposed to allow for the design of these SDG using the AISC design equations. Received: Revised: Accepted: 23 December 2017 26 July 2018 12 August 2018","PeriodicalId":56332,"journal":{"name":"Advanced Steel Construction","volume":"15 1","pages":"157-164"},"PeriodicalIF":1.7,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67606887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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