This input screen is displayed when the two check boxes in the Web Stiffening and Local Transverse Forces section in the Cold-Formed section of the Details dialog box (see Chapter 3.1.7) are selected. In Window 1.14, you can define the parameters that are required for the local transverse force design according to EN 1993-1-3 [3] 6.1.7 for cold-formed sections. This design ensures that there is no compression or buckling of the web due to local transverse forces through the flange into the web.
The local transverse force design is only possible for cross-sections with non-stiffened webs according to [3] 6.1.7.2 and 6.1.7.3. Web cross-sections with longitudinal stiffenings cannot be designed according to [3] 6.1.7.4.
In the upper part of the window, you can specify for which members the local transverse force design should be performed and which length of the stiff bearing is to be applied in each case. If you enter the transverse forces manually, you can set specific settings for the member selected above in the Settings section.
The consideration of the Transverse Forces is activated for all members by default. Thus, the shear force distribution is used for the design of the web loading for local load application. If the check box in column A is cleared in one row, this design is omitted for the corresponding member.
During the design, the locations of discontinuity resulting from the shear force distribution are analyzed. All parameters for determining the web resistance Rw,Rd are determined automatically; the Nominal length of stiff bearing ss is preset to 0.10 m, but can be adjusted globally for each member. If the internal force distribution of a member does not represent the actual conditions, the introduced load can be defined individually. To do this, activate Manual input in column B. In doing so, additional fields in the table and in the Settings become accessible.
The Number of shear loads determines how many design locations exist on the member. In the Local Transverse Forces columns, you can define positions x for which you want to perform an analysis. These locations can be arranged anywhere on the member: The design only uses the parameters that have to be defined for each position in the Settings section.
When entering the data manually, specify the design value of the Transverse Force FEd. If there is Influence of Free End, the resistance of the web Rw,Rd for the geometry condition c ≤ 1.5 hw is determined, for example, according to [3] Equation (6.15a), (6.15b), or (6.15c); for cross-sections with two or more stiffened webs, category 1 according to [3] Figure 6.9 is applied. When the check box is cleared, [3] Equation (6.15d) or (6.15e) is used. The Influence of Opposing Force or Support check box controls whether the design is performed according to [3] Figure 6.1 a) or Figure 6.7 b) for cross-sections with only one web. If it is selected, a distance e ≤ 1.5 hw is assumed. Cross-sections with two webs are classified in category 1 (see [3] Figure 6.9). The Prevented web rotation check box controls whether the resistance of the web Rw,Rd is determined with equations according to [3] 6.1.7.2(4). For each position, the Nominal length of stiff bearing ss can be specified by the user. When designing a cross-section with two webs, the Ratio of shear forces VEd,2/VEd,1, with which the effective support length la is calculated according to [3] 6.1.7.3(4) for category 2, has to be specified as well. βv is determined as follows:
An example of local load introduction design is presented in a technical article that can be found in the Knowledge Base on our website.
Literature