This window is displayed by selecting New Analysis from the File menu. The Analysis Wizard is used to easily create the geometry and loads for many common beam and column configurations. Once you finish the Wizard, you have full editing capabilities for the analysis.
The second page of the Analysis Wizard is used to define the parameters for members and supports. After you enter the parameters you want, press the Next button to proceed to the next page (see Page 3).
| Section | The name of the section file to use for the members. This drop-down list contains all of the sections currently open in CFS. |
| Span Lengths | The length of each span, or distance between vertical supports, separated by commas (or periods if a comma is your decimal separater). You may enter up to 20 spans. |
| Cantilever Length | The length of cantilever beyond the first and last supports. |
| Lap Length | The length of beam overlap on each side of the supports. Lapped members are assumed to provide full continuity. This input is only available for Multi-Span Beam with Laps. |
| Fixed End Supports | Indicates whether the extreme ends of the members are in rotation about both the X and Y axes. If checked, you cannot have a cantilever length. |
| Bearing Length | The length of bearing in the longitudinal direction (width of the supports). |
| Fastened Support | Indicates whether the bearing flanges are fastened to the supports. This can affect the web crippling strength at the support. |
| Member Bracing | Indicates the type of bracing between vertical supports: None, Mid-Point, Third-Points, Quarter-Points, or Fully Braced. This will create horizontal (X) and torsional (T) supports at the specified intervals. These brace points will restrain all flanges against twisting and lateral movement. |
| Braced Flange | For members having one flange fastened to deck, sheathing, roof system, or other continually connected system, select the flange that is attached: Bottom, Top, Left, or Right. Otherwise, select None. You can have both a braced flange and discrete member bracing at the same time. |
| Moment Reduction, R | If there is a braced flange, enter the moment reduction factor as defined in the
AISI or ASCE Specification for your situation. For example: R=0.70 for continuous span Z sections R=0.60 for continuous span C sections R=0.70 for simple span C or Z section, depth £ 6.5" R=0.65 for simple span C or Z section, 6.5" < depth £ 8.5" R=0.50 for simple span Z section, 8.5" < depth £ 12" R=0.40 for simple span C section, 8.5" < depth £ 12" |
| Stiffness, kf | The rotational stiffness provided to the braced flange by connection to the bracing material (deck, sheathing, etc.). This stiffness is incorporated in the distortional buckling calculations for the flange which is braced (bottom, top, left, or right). The units for this input are moment/radian/unit length (such as k-in/rad/in) which is then reduced to a force (such as k). Refer to the AISI Specification and Commentary for more information on determining what value to use. |
| Length, Lm | The distance along the
length of the member between discrete rigid restraints that restrict
distortional buckling. If there are no discrete restraints for distortional
buckling, leave this as a large value (such as the span length) and CFS will
calculate the distortional buckling wavelength. If the member is fully
restricted against distortional buckling, use Lm = 0. If the shape does not
have a distortional buckling failure mode, the value of Lm has no effect. In cases where rotational stiffness is provided to the braced flange by connection to bracing material, Lm does not represent the spacing between fasteners. It is the distance between rigid restraints against distortional buckling, if they exist. |