• Steel and Composite Structures
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• 제21권3호
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• pp.629-659
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• 2016

In cold-formed stainless steel lipped channel-sections, web openings are becoming increasingly popular. Such openings, however, result in the sections becoming more susceptible to web crippling, especially under concentrated loads applied near the web opening. This paper presents the results of a finite element parametric study into the effect of circular web openings on the web crippling strength of cold-formed stainless steel lipped channel-sections for the interior-one-flange (IOF) loading condition. This involves a bearing load applied to the top flange of a length of member, away from the end supports. The cases of web openings located centred beneath the bearing load (i.e. beneath the bearing plate delivering the load) and offset to the bearing plate, are considered. Three grades of stainless steel are considered: duplex EN1.4462, austenitic EN1.4404 and ferretic EN1.4003. In total, 2218 finite element models were analyzed. From the results of the parametric study, strength reduction factors for load bearing capacity are determined, where these reduction factors are applied to the bearing capacity calculated for a web without openings, to take account the influence of the web openings. The strength reduction factors are first compared to equations recently proposed for cold-formed carbon steel lipped channel-sections. It is shown that for the case of the duplex grade, the strength reduction factor equations for cold-formed carbon steel are conservative but only by 2%. However, for the cases of the austentic and ferritic grades, the cold-formed carbon steel equations are around 9% conservative. New strength reduction factor equations are proposed for all three stainless steel grades.

• Steel and Composite Structures
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• 제23권3호
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• pp.363-383
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• 2017

In cold-formed stainless steel lipped channel-sections, use of web openings for service purposes are becoming increasingly popular. Web openings, however, result in the sections becoming more susceptible to web crippling. This paper presents a finite element investigation into the web crippling strength of cold-formed stainless steel lipped channel-sections with circular web openings under the interior-two-flange (ITF) loading condition. The cases of web openings located centred and offset to the bearing plates are considered in this study. In order to take into account the influence of the circular web openings, a parametric study involving 2,220 finite element analyses was performed, covering duplex EN1.4462, austenitic EN1.4404 and ferritic EN1.4003 stainless steel grades. From the results of the parametric study, strength reduction factor equations are proposed. The strengths obtained from reduction factor equations are first compared to the strengths calculated from the equations recently proposed for cold-formed carbon steel lipped channel-sections. It is demonstrated that the strength reduction factor equations proposed for cold-formed carbon steel are unconservative for the stainless steel grades by up to 17%. New coefficients for web crippling strength reduction factor equations are then proposed that can be applied to all three stainless steel grades.

• 한국강구조학회 논문집
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• 제15권2호
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• pp.109-116
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• 2003

벽체용 박판냉간성형 Lip-C-형강의 구조적인 거동에 관한 연구의 일환으로 횡하중을 받는 스터드 벽체의 휨강도에 관한 실험적인 연구가 수행되었다. 시험체는 3개 또는 4개의 Lip-C-형강 스터드 부재의 양단을 C-형강 트랙으로 고정하여 제작되었다. 실험의 주요 변수는 스터드 복부의 천공 여부, 보강채널(bridge channel)의 간격 및 개수 그리고 보강 채널의 고정 및 스터드 플랜지의 간격 유지용 특수 클립(Clip)의 개수 등이며, 스터드의 인장측 플랜지에 부착된 합판과 석고보드의 벽에 강도에 미치는 영향이 연구되었다. 실험에 의한 휨강도는 AISI시방서(1996)에 근거한 강도와 비교하였다.

• Advances in Computational Design
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• 제3권1호
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• pp.71-86
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• 2018

Thin-walled cross-sections can be optimized to enhance their resistance and progress their behaviour, leading to more competent and inexpensive structural system. The aim of this study is to afford a methodology that would facilitate progress of optimized cold formed steel (CFS) column section with maximum ultimate strength for practical applications. The proposed sections are designed to comply with the geometrical standards of pre-qualified column standards for CFS structures as well as with the number of industrialized and practical constraints. The stiffening evaluation process of CFS lipped channel columns, a five different cross section are considered. The experimental strength and behaviour of the proposed sections are verified by using the finite element analysis (FEA). A series comprehensive parametric study is carried out covering a wide range of section slenderness and overall slenderness ratio of the CFS column with and without intermediate web stiffeners. The ultimate strength of the sections is determined based on the Direct Strength Specification and other design equation available from the literature for CFS structures. A modified design method is proposed for the DSM specification. The results indicate that the CFS column with complex edge and intermediate web stiffeners provides an ultimate strength which is up to 78% higher than standard optimized shapes with the same amount of cross sectional area.

• 한국강구조학회 논문집
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• 제17권1호통권74호
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• pp.83-92
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• 2005

본 논문은 압축과 모멘트 조합하중을 받는 냉간성형강 기둥의 내력성능을 평가하는데 목적이 있다. 단면은 춤이 90, 150 mm이고 웨브에 엠보싱이 있는 립 ㄷ형강이다. 부재길이와 단부모멘트비를 변수로 하였고, 편심압축력을 가력하여 총 24개 실물실험을 수행하였다. 미국 AISI와 유럽 EC3 기준의 특징을 체계적으로 분석하였고, 실험결과와 기준 산정결과를 비교하였다. 두 기준 모두 합리적임을 알 수 있었다.

• 전산구조공학
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• 제9권4호
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• pp.135-140
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• 1996

박벽개단면을 갖는 단일 형강재는 압축재로 될 수 있는데 예를 들면 트러스에서 복재가 이런 경우이다. 이 때에는 부재의 조립 때문에 발생하는 필연적 편심을 구조설계시에는 보통 무시한다. 그러나 편심의 영향은 부재를 설계할 때, 특히 압축부재의 설계에서는 고려되어야 할 사항이다. 비틀림이나 혹은 휨과 비틀림에 의해서 좌굴을 일으키는 압축재의 임계하중은 지배하는 비분방정식의 해를 구함으로써 결정된다. 본 논문에서는 채널([), 등변앵글(L), 리프채널(C)의 편심변화에 따른 내하력을 도표로 나타내기로 한다. 또한 식이복잡하므로 컴퓨터를 이용하여 계산한 후, 그 결과를 SURFER프로그램을 사용하여 그래프로 표시하였다.

• Steel and Composite Structures
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• 제44권1호
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• pp.33-47
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• 2022

This paper presents a finite element model for predicting the monotonic behaviour of bolted endplate joints connecting steel-concrete composite walls and steel beams. The demountable Hollo-bolts are utilised to facilitate the quick installation and dismantling for replacement and reuse. In the developed model, material and geometric nonlinearities were included. The accuracy of the developed model was assessed by comparing the numerical results with previous experimental tests on hollow/composite column-to-steel beam joints that incorporated endplates and Hollo-bolts. In particular, the Hollo-bolts were modelled with the expanded sleeves involved, and different material properties of the Hollo-bolt shank and sleeves were considered based on the information provided by the manufacture. The developed models, therefore, can be applied in the present study to simulate the wall-to-beam joints with similar structural components and characteristics. Based on the validated model, the authors herein compared the behaviour of wall-to-beam joints of two commonly utilised composite walling systems (Case 1: flat steel plates with headed studs; Case 2: lipped channel section with partition plates). Considering the ease of manufacturing, onsite erection and the pertinent costs, composite walling system with flat steel plates and conventional headed studs (Case 1) was the focus of present study. Specifically, additional headed studs were pre-welded inside the front wall plates to enhance the joint performance. On this basis, a series of parametric studies were conducted to assess the influences of five design parameters on the behaviour of bolted endplate wall-to-beam joints. The initial stiffness, plastic moment capacity, as well as the rotational capacity of the composite wall-to-beam joints based on the numerical analysis were further compared with the current design provision.