Parametric Studies on Inter-Column Brace Forces

Abstract

In past studies on the design forces of inter-column braces, only the randomness of the initial imperfections of the columns was considered and the horizontal inter-column braces located at mid-height of columns were assumed to be effective only in compression. Actually, the initial imperfections of both the columns and the braces are random variables and the combination of the initial imperfections between them is also random. In this paper, the initial imperfections of the columns and the braces were randomly taken by Monte Carlo method, and a large number of the column-bracing systems with random combinations of the initial imperfections were modeled and analyzed by second-order analysis using finite element method. The binormal probability density function of bracing forces was found based on numerical calculations, parametric analyses and probability statistics. The results indicate that random combination of the initial imperfections between columns and braces leads to the randomness of horizontal inter-column brace forces in compression or in tension. The design forces of these braces have been obtained and a design formula has also been proposed. It is found that the design forces of these braces are smaller than those given in GB50017–2003, Eurocode 3 -1992 and AS4100–1998.

Keywords

inter-column braces bracing forces Monte Carlo method initial imperfection random combination binormal distribution

Get full access to this article

View all access options for this article.

References

Australian standard (1998). Steel Structures (AS4100–1998), Standards Association of Australia.

Eurocode 3 (1992). Design of Steel Structures, Part 1.1: General Rules and Rules for Buildings, Commission of European Communities, Brussels.

GB50017–2003 (2003). Code for Design of Steel Structures, Chinese Planning Press, China (in Chinese).

Heungbae

and Yura

J.A.

(1999). “Bracing requirements of inelastic columns”, Journal of Constructional Steel Research, Vol. 51, No. 1, pp. 1–19.

Plaut

R.H.

(1993). “Lateral bracing forces in columns with two unequal spans”, Journal of Structural Engineering, ASCE, Vol. 119, No. 10, pp. 2896–2913.

Vickey

P.J.

and Twisdale

L.A.

(1995). “Prediction of hurricane wind speeds in the United States”, Journal of Structural Engineering, ASCE, Vol. 121, No. 11, pp. 1691–1699.

Tong

G.S.

(1986). “Design approach of horizontal braces between columns”, Journal of Xi'an Institute of Metallurgy and Construction Engineering, Vol. 20, No. 3, pp. 110–140 (in Chinese).

Tong

G.S.

and Chen

S.F.

(1987). “Design forces of horizontal inter-column braces”, Journal of Constructional Steel Research, Vol. 7, No. 5, pp. 363–370.

Tong

G.S.

and Chen

S.P.

(2003). “Design requirements for bracings between columns”, Industrial Construction, Vol. 33, No. 5, pp. 9–12 (in Chinese).

10.

Winter

(1958). “Lateral bracing of columns and beams”, Journal of Structural Division, ASCE, Vol. 84, No. ST2, pp. 1561:1–22.

11.

Z.J.

(1985). Monte Carlo Method, Shanghai Technology and Science Publishing House, Shanghai, China (in Chinese).

12.

Yura

J.A.

(1996). “Winter's bracing approach revised”, Engineering Structures, Vol. 18, No. 10, pp. 821–825.

13.

Zhao

J.Y.

(2005). Study on the Design Method of Braces Between the Columns, Master Thesis, Harbin Institute of technology, harbin, China (in Chinese).