Cross frame definition

The Cross-frame definition dialog is used to define all the profiles needed within the current project for transverse components of the bridge superstructure like diaphragms and cross-frames.

On the top of the dialog there are two options in order to select the profile type (CF type) and name (CF name).The CF type provides a list of predefined shapes: one chord, two chords, X-frame, K-frame, Inverted K-frame, Rhomb- frame commonly used in practice.

Depending on the selected CF type the picture will be actualized and each structural member of the cross frame will be available for definition: Top chord, Bottom chord, Diagonals. For each of them you must press the Profile ID button and select from the list the appropriate steel profiles created in Profile definition dialog. If no profile is present you have the option to Add a new one and you will be transferred directly to Profile Definition dialog where you can create the necessary profile.

Setting

Description

Alignment reference points

These points are typical points in cross-sections to be used for measuring distances between different parts or members. So for each chord or diagonal you must specify a reference point (AR Chord/AR Diagonal) depending on the profile type used, and two points on the left/right main girders (AR girder left/AR girder right) between which distances will be measured.

Distances

Setting	Description
Chord	d-left: Distance from AR girder left point situated on main member to AR Chord point. d-right: Distance from AR girder right point situated on main member to AR Chord point.
Diagonal	d-left: Distance from AR girder left point situated on main member to AR Diagonal point. d-right: Distance from AR girder right point situated on main member to AR Diagonal point. d-center: For K–frames we have a convention for arrangement of diagonals at center of chords.

Layout

depending on the desired cross frame type, you can select between 3 types: regular, parallel and arbitrary that will ease the input of distances in the cross frame definition menu.

Regular: when this option is selected, a modified value for distance is copied to all other distance inputs.
Parallel: allows copying one distance input value from left to right and vice-versa.
Arbitrary: this option allows user to input different values for each of distance inputs, without any copy.

Cross frames usually consist of angles or WT sections, while diaphragms use channels or I-sections so the list restricts T-shaped and Rectangular profiles which are used in Stiffeners definition dialog and vice-versa.

After selecting the right distances/profile Id’s and a name In CF name field is entered just click Add and a new Cross frame profile is present in the list on the right side of the dialog. Using modify option changes can be applied to an existing profile in the list, but the name cannot be changed anymore.