الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Designing purl ins for roof systems attached to through-fastened panels has been a subject well researched in the past. The AISI and AS/NZS specifications are using a simplified approach to the design of these members where the fully braced moment capacity of such members is multiplied by a reduction factor (R-value) in cases of
braced tension flange. This value represents the point in between of the fully braced and fully unbraced member behavior. There was a big difference between the two provisions in conditions of the R-value. The R-value changes depending mainly on section depth in AISI. However, the AS/NZS provisions depend on number of points
that laterally braced for R-value determination. Design of purlins that have laterally braced tension flanges as laterally unsupported is very conservative. Since the Egyptian code had no specifications for the design of such cases, the experimental investigation was conducted in collaboration with Mancrew and Alex Steel to determine the R-value and compare the results with the values of AISI and AS/NZS. The test setup was as similar as possible to the previous R-
value tests. Since AISI S 100 and AS/NZS 4600 has limitations to the design equation, comparisons were done between the test setup and the equation limitations. Based on the findings of this test program, the R-value was closer to AS/NZS provisions. For C-purlins, the R-value found to be 0.71 for depth d:S 6.5 in (165mm) and for 6.5in (165mm) < d:S 8.5in (216mm) was 0.702. No significant change happened when deeper section was used.