• Structural Engineering and Mechanics
• /
• v.74 no.3
• /
• pp.381-394
• /
• 2020

The structural performance of cold-formed steel (CFS) built-up battened columns were numerically investigated in this paper. The built-up column sections were formed by connecting two-lipped channels back-to-back, with a regular spacing of battens plates, and have been investigated in the current study. Finite element models were validated with the test results reported by the authors in the companion paper. Using the validated models, the parametric study was extended, covering a wider range of overall slenderness to assess the accuracy of the current design rules in predicting the design strengths of the CFS built-up battened columns. The parameters viz., overall slenderness, different geometries, plate slenderness (b/t ratio) and yield stress were considered for this study. In total, a total of 228 finite element models were analyzed and the results obtained were compared with current design strength predicted by Effective Width Method of AISI Specifications (AISI S100:2016) and European specifications (EN1993-1-3:2006). The parametric study results indicated that the current design rules are limited in predicting the accuracy of the design strengths of CFS built-up battened columns. Therefore, a design equation was proposed for the AISI and EC3 specifications to predict the reliable design strength of the CFS Built-up battened columns and was also verified by the reliability analysis.

• Journal of the Korean housing association
• /
• v.5 no.2
• /
• pp.29-40
• /
• 1994

The purpose of this study is to survey the transition of the type of openings in korean traditional archiectures. To do this, various types of openings at the backside of Daechung of 23 Hyang-Gyo Myung-Ryun-Dangs were investigated. After the classification in some groups according to their types and their periods of constuction, the tasnsition of the type of openings was analysed. Results are as follows. (1) The openings constructed form 16th to 17th century, the earliest form, is a ledged and battened panel window(or framed and ledged panel window) whose mullion is built on the frame of window. It is presumed that these types were widely used before 17th century. (2) The next type is ledged and battened panel window(door) (or framed and ledged panel window) which lacks a mullion. These types were thought to be customed after 18th century. (3) The lastest type, which is appeared from 19th to 20th century, is an characteristic backside opening(ledged and battened panel window or framed and ledged panel window) that among 3 column spacings the central one is enlarged in comparison with the right and left ones. Through this transition pattern of the openings, can be menifested that the trend of 20th century is to enlarge convenience of usage by constuctiong door and eliminating some windows.

• Structural Engineering and Mechanics
• /
• v.83 no.3
• /
• pp.387-400
• /
• 2022

The practice of using encased steel-concrete columns in medium to high-rise structures has expanded dramatically in recent years. The study evaluates existing methodologies and codal guidelines for estimating the ultimate load-carrying characteristics of concrete-encased short columns experimentally. The present condition of composite column design methods was analyzed using the Egyptian code ECP203-2007, the American Institute of Steel Construction's AISC-LRFD-2010, Eurocode EC-4, the American Concrete Institute's ACI-318-2014, and the British Standard BS-5400-5. According to the codes, the axial load carrying characteristics of both the encased steel and concrete sections was examined. The effect of load-carrying capacities in different forms of encased steel sections on encased steel-concrete columns was studied experimentally. The axial load carrying capacity of twelve concrete-encased columns and four conventional reinforced columns were examined. The conclusion is that the confinement was not taken into account when forecasting the strength and ductility of the encased concrete, resulting in considerable disparities between codal provisions and experimental results. The configuration of the steel section influenced the confining effect. Better confinement is achieved with the laced and battened section than with the infilled steel tube reinforced and conventionally reinforced section. The ECP203-2007 code reported the most conservative results of all the codes used.