D3.C.7 Composite Sections

The definition of composite sections has been provided for in the standard sections definition (refer to TR.20.1 Assigning Properties from Steel Tables for details). This is purely for analysis and for obtaining the right section properties. It uses the American requirement of 18 times depth (CT) as the effective depth. For more control with British sections two new options are available in user provided tables.

D3.C.7.1 Wide Flange Composite

Using the standard definition of I sections in WIDE FLANGE, 4 additional values can now be provided. The first is the width of concrete to the left of center of the steel web (b1). The second is the concrete width to the right (b2). The third is the concrete depth (d1) to be considered. The last is the modular ratio. The above values are accepted in the program by adding a '-' at the first position on the first line of data. The program now awaits four extra values on line 2 as described above. If (-) is provided on the second line the program requires another 2 breadths + 1 thickness for the bottom plate.

D3.C.7.2 I Section

The same is true for ISECTION definition in user table.

D3.C.7.3 Example

UNIT  CM
WIDE  FLANGE
C45752
-66.5  44.98 .76 15.24 1.09 21345 645 21.3 34.185 33.223 
150  150 30 10
ISECTION
PG9144
-92.05  2.15 92.05 42.05 3.66 42.05 3.66 197.9 153.9 1730
40 40  12 1

The larger British sections have been coded as USER TABLES under wide flange and are available on request to any existing user. Please note however that composite design is not available in this portion of STAAD.