The Web Crippling Check report is created when you choose Web Crippling from the Compute menu. For sections, you must enter the web crippling parameters and loads. For an analysis, you must select the member locations to perform the check(s).
This report consists of a summary of the web crippling parameters and loads, web crippling strength computations, and the appropriate interaction equation(s). For an analysis with multiple members at the specified location, the bearing load and bending moment on each member is proportional to its moment of inertia about the axis of bending.
The web crippling strength of the section is determined by summing the strengths of all the web elements. If other elements in the section lie between a web element's bearing flange and the bearing surface, that web element will be excluded from the strength summation.
The appropriate web crippling equation from the selected specification is determined for each web. The following abbreviations are used in classifying the type of calculation performed for each element:
FS FU US UU |
Fastened, Stiffened flange Fastened, Unstiffened flange Unfastened, Stiffened flange Unfastened, Unstiffened flange | |
EOF ETF IOF ITF |
End-One-Flange loading End-Two-Flange loading Interior-One-Flange loading Interior-Two-Flange loading |
If any parameters exceed the limits imposed by the selected specification (R/t, h/t, N/t, N/h, etc.), those limits are noted for each web element checked.
For web elements that do not have a bearing flange, the same equations are used with a zero bend radius. For web elements with holes, the hole is assumed to be positioned longitudinally at the edge of bearing. Although the hole provisions apply to C-sections with centered web holes, CFS uses the same calculations for other conditions.
If the bearing flange is not perpendicular to the direction of loading, the strength in the direction of loading is determined by dividing the strength by the cosine of the angle between the flange and the surface perpendicular to the direction of loading. This assumes that the component parallel to the flange is resisted by an adequate connection.
If any of the web element strengths listed should not be considered, be sure to subtract it from the section strength. This might occur if the support does not contact all of the assumed bearing flanges.