Title:
ROLL-FORMED RECTANGULAR STEEL TUBE
Document Type and Number:
WIPO Patent Application WO/2014/142205
Kind Code:
A1
Abstract:
Provided is a roll-formed rectangular steel tube having a cross sectional shape capable of increasing or at least sustaining the local buckling stress level, second moment of area, or section modulus compared to conventional rectangular steel tubes even with smaller cross sectional areas. The roll-formed rectangular steel tube: satisfies equations (1) and (2) when the width-to-thickness ratio (A/t or B/t), which is the ratio of the vertical side length (A) or the horizontal side length (B) to the thickness (t), is x and the yield stress level for design is F(N/mm2); satisfies equation (3) when the ratio (CA/A) of the corner length in the vertical direction (CA) and the vertical side length (A) or the ratio (CB/B) of the corner length in the horizontal direction (CB) and the horizontal side length (B) is y; and satisfies condition (4) of satisfying one of either equation (41) or equation (42). 15.6≤x≤740/√F (1). 235≤F≤325 (2). y≤0.30 (3). For 15.6≤x<25.5, y≥-0.0061x+0.2557 (41). For 25.5≤x≤740/√F, y≥0.1 (42). However, the case of y=0.16 is excluded.
Inventors:
OKADA TADAYOSHI (JP)
KAWABATA YOSUKE (JP)
KAWABATA YOSUKE (JP)
Application Number:
PCT/JP2014/056578
Publication Date:
September 18, 2014
Filing Date:
March 12, 2014
Export Citation:
Assignee:
NIPPON STEEL & SUMIKIN METAL PRODUCTS CO LTD (JP)
International Classes:
E04C3/04; E04B1/24; E04C3/32
Foreign References:
| JP2004330222A | 2004-11-25 | |||
| JP2006328942A | 2006-12-07 |
Other References:
TOYO SUPERIOR STEELTUBE WORKS CO., LTD., TOYO TOKUSHU NO KAKU KOKAN SIZE HYO SEKKEI SHIRYO, vol. 15, 2007, pages 1 - 29
Attorney, Agent or Firm:
KAGAWA Yukihiko et al. (JP)
Masahiko Kagawa (JP)
Masahiko Kagawa (JP)
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