Study of the strength and behaviour of single-coped beam under combined bending, shear and axial loads

IF 5.7 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures Pub Date : 2025-03-31 DOI:10.1016/j.tws.2025.113258

Michael C.H. Yam , Xiuzhang He , Mingyuan Zhang , Jinqi Yang , Ke Ke

{"title":"Study of the strength and behaviour of single-coped beam under combined bending, shear and axial loads","authors":"Michael C.H. Yam , Xiuzhang He , Mingyuan Zhang , Jinqi Yang , Ke Ke","doi":"10.1016/j.tws.2025.113258","DOIUrl":null,"url":null,"abstract":"<div><div>Coped beams are often used as a secondary member to support a floor slab system. The coped beam ends are achieved by removing the flange(s) of the beam to facilitate the connection to the main beam. Although coped beams are mainly used to resist gravity loads in a building structure, the beams may be subjected to axial force due to the transfer of lateral loads such as wind loads from the building façade to the lateral load resisting system. Hence, the coped beams are subjected to combined loadings of bending, shear and axial force. However, existing design methods for single-coped beams do not account for the influence of axial loads and the combined load effects. This study presents an experimental and numerical investigation of the structural behaviour and local web buckling strength of single-coped beams under combined bending, shear and axial loading scenarios. Ten full-scale tests of single-coped beams subjected to combined loadings were conducted with varied test parameters including the axial force level, cope details and web slenderness ratio. In general, all the test specimens failed by local web buckling at the coped region. The test results demonstrated that the ultimate strength of the coped beam specimens subjected to gravity loads decreased with the presence of compressive axial force. For instance, a compressive axial force corresponding to 4 % of the section yield load reduced the ultimate strength of a coped beam specimen by 10.1 % when comparing to that without the compressive force. Finite element (FE) analyses were subsequently conducted to further explore the effect of axial force on the strength and behaviour of coped beams with various cope details. It was found that the existing design methods, which do not account for the combined load effects, could not produce satisfactory predictions of the web buckling strength of single-coped beams when compared to the test and FE results. To address these shortcomings, a design equation was proposed to evaluate the strength of the coped beams under combined bending, shear and axial loads. The test-to-predicted ratios based on the proposed design equation ranged from 0.94 to 1.22 with a mean value of 1.05 and a coefficient of variation of 0.07. A reliability analysis was conducted, and the results indicated that a partial factor of <em>γ<sub>M</sub></em> = 1.09 was suggested for practical application to ensure safety and reliability in structural design.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"213 ","pages":"Article 113258"},"PeriodicalIF":5.7000,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thin-Walled Structures","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0263823125003520","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}

引用次数: 0

Abstract

Coped beams are often used as a secondary member to support a floor slab system. The coped beam ends are achieved by removing the flange(s) of the beam to facilitate the connection to the main beam. Although coped beams are mainly used to resist gravity loads in a building structure, the beams may be subjected to axial force due to the transfer of lateral loads such as wind loads from the building façade to the lateral load resisting system. Hence, the coped beams are subjected to combined loadings of bending, shear and axial force. However, existing design methods for single-coped beams do not account for the influence of axial loads and the combined load effects. This study presents an experimental and numerical investigation of the structural behaviour and local web buckling strength of single-coped beams under combined bending, shear and axial loading scenarios. Ten full-scale tests of single-coped beams subjected to combined loadings were conducted with varied test parameters including the axial force level, cope details and web slenderness ratio. In general, all the test specimens failed by local web buckling at the coped region. The test results demonstrated that the ultimate strength of the coped beam specimens subjected to gravity loads decreased with the presence of compressive axial force. For instance, a compressive axial force corresponding to 4 % of the section yield load reduced the ultimate strength of a coped beam specimen by 10.1 % when comparing to that without the compressive force. Finite element (FE) analyses were subsequently conducted to further explore the effect of axial force on the strength and behaviour of coped beams with various cope details. It was found that the existing design methods, which do not account for the combined load effects, could not produce satisfactory predictions of the web buckling strength of single-coped beams when compared to the test and FE results. To address these shortcomings, a design equation was proposed to evaluate the strength of the coped beams under combined bending, shear and axial loads. The test-to-predicted ratios based on the proposed design equation ranged from 0.94 to 1.22 with a mean value of 1.05 and a coefficient of variation of 0.07. A reliability analysis was conducted, and the results indicated that a partial factor of γ_M = 1.09 was suggested for practical application to ensure safety and reliability in structural design.

查看原文本刊更多论文

弯曲、剪切和轴向联合荷载作用下单向梁的强度和性能研究

复盖梁通常用作支撑楼板系统的次要构件。复制梁端是通过去除梁的法兰来实现的，以方便与主梁的连接。虽然叠接梁主要用于抵抗建筑结构中的重力荷载，但由于侧向荷载（如风荷载）从建筑立面转移到侧向荷载抵抗系统，梁可能会受到轴向力的影响。因此，叠接梁受到弯曲、剪切和轴力的联合荷载。然而，现有的单向梁设计方法没有考虑轴向荷载和组合荷载的影响。本研究对弯曲、剪切和轴向复合荷载作用下的单向梁的结构性能和局部腹板屈曲强度进行了实验和数值研究。采用不同的试验参数，包括轴力水平、截面细节和腹板长细比，对受组合荷载作用的单叠梁进行了10次全尺寸试验。总的来说，所有试件的破坏都是由于局部腹板屈曲造成的。试验结果表明，在轴向压缩力作用下，受重力荷载作用的叠合梁试件的极限强度降低。例如，压缩轴向力相当于截面屈服荷载的4%，与没有压缩力的试件相比，压缩梁试件的极限强度降低了10.1%。随后进行了有限元（FE）分析，以进一步探讨轴向力对具有不同cope细节的copy梁的强度和性能的影响。结果表明，现有的设计方法未考虑组合荷载的影响，与试验和有限元计算结果相比，不能给出令人满意的单向梁腹板屈曲强度预测。针对这些不足，提出了一种计算叠合梁在弯曲、剪切和轴向复合荷载作用下强度的设计方程。基于设计方程的试验预测比范围为0.94 ~ 1.22，平均值为1.05，变异系数为0.07。进行了可靠度分析，结果表明，为保证结构设计的安全可靠，在实际应用中建议采用γM = 1.09的偏系数。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Thin-Walled Structures 工程技术-工程：土木

CiteScore

9.60

自引率

20.30%

发文量

801

审稿时长

66 days

期刊介绍： Thin-walled structures comprises an important and growing proportion of engineering construction with areas of application becoming increasingly diverse, ranging from aircraft, bridges, ships and oil rigs to storage vessels, industrial buildings and warehouses. Many factors, including cost and weight economy, new materials and processes and the growth of powerful methods of analysis have contributed to this growth, and led to the need for a journal which concentrates specifically on structures in which problems arise due to the thinness of the walls. This field includes cold– formed sections, plate and shell structures, reinforced plastics structures and aluminium structures, and is of importance in many branches of engineering. The primary criterion for consideration of papers in Thin–Walled Structures is that they must be concerned with thin–walled structures or the basic problems inherent in thin–walled structures. Provided this criterion is satisfied no restriction is placed on the type of construction, material or field of application. Papers on theory, experiment, design, etc., are published and it is expected that many papers will contain aspects of all three.