Experimental study of LSF truss floor-ceiling systems made of top hat sections

IF 5.7 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures Pub Date : 2025-03-11 DOI:10.1016/j.tws.2025.113193

Gihan Ranasinghe , Son Tung Vy , Mahen Mahendran , Anthony Ariyanayagam

{"title":"Experimental study of LSF truss floor-ceiling systems made of top hat sections","authors":"Gihan Ranasinghe , Son Tung Vy , Mahen Mahendran , Anthony Ariyanayagam","doi":"10.1016/j.tws.2025.113193","DOIUrl":null,"url":null,"abstract":"<div><div>Light gauge steel framed (LSF) floor-ceiling systems, which employ cold-formed steel (CFS) joists, offer high strength, fast construction and cost-effectiveness. CFS trusses are examples of such joists with several advantages over conventional lipped channel joists. However, limited research exists on LSF truss floor-ceiling systems made of top hat sections, despite their popularity. This study addressed this gap by examining the flexural behaviour of LSF truss floor-ceiling systems made of top hat sections through a series of four-point bending tests. The experiments were conducted with variations in support conditions, truss configurations, top hat thickness, and the types of fasteners used in web-to-chord connections. Test results highlighted the complex failure mechanisms of top hat trusses, including early local buckling failures at the removed lips and edge stiffeners near the ends of diagonal web members. The use of nylon spacers and additional screws to the bolt connections proved effective in delaying early web member failures. Tested trusses did not fail abruptly, instead, the loads were redistributed to other members, resulting in higher ultimate failure loads. A comparison with the current truss design method which is based on elastic analysis to determine member forces and the direct strength method (DSM) to calculate member capacities showed that this approach overestimates the truss failure loads, particularly where web-to-chord connections had only one bolt. This research underscores the need to consider combined compression-bending actions when designing web members with eccentric connections and to strengthen these connections to prevent or delay early local buckling failures. It also highlights the importance of considering the unlipped portion of web members at connections when designing top hat trusses and provides design recommendations for top hat truss floor systems.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"212 ","pages":"Article 113193"},"PeriodicalIF":5.7000,"publicationDate":"2025-03-11","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/S0263823125002873","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

Light gauge steel framed (LSF) floor-ceiling systems, which employ cold-formed steel (CFS) joists, offer high strength, fast construction and cost-effectiveness. CFS trusses are examples of such joists with several advantages over conventional lipped channel joists. However, limited research exists on LSF truss floor-ceiling systems made of top hat sections, despite their popularity. This study addressed this gap by examining the flexural behaviour of LSF truss floor-ceiling systems made of top hat sections through a series of four-point bending tests. The experiments were conducted with variations in support conditions, truss configurations, top hat thickness, and the types of fasteners used in web-to-chord connections. Test results highlighted the complex failure mechanisms of top hat trusses, including early local buckling failures at the removed lips and edge stiffeners near the ends of diagonal web members. The use of nylon spacers and additional screws to the bolt connections proved effective in delaying early web member failures. Tested trusses did not fail abruptly, instead, the loads were redistributed to other members, resulting in higher ultimate failure loads. A comparison with the current truss design method which is based on elastic analysis to determine member forces and the direct strength method (DSM) to calculate member capacities showed that this approach overestimates the truss failure loads, particularly where web-to-chord connections had only one bolt. This research underscores the need to consider combined compression-bending actions when designing web members with eccentric connections and to strengthen these connections to prevent or delay early local buckling failures. It also highlights the importance of considering the unlipped portion of web members at connections when designing top hat trusses and provides design recommendations for top hat truss floor systems.

查看原文本刊更多论文

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.