Curtain Wall – Profile Division vs Profile Joint

Schucal FWS family has two options for creating profile joint for mullion or transom.

The first type is Profile Division.

This is the simple method that creates divisions for all profile members (mullion, pressure plate, cover cap, insulator). This method only divides the members, does not add any structural connectors to the division.

Right click on the profile you want to add the division to (mullion or transom) and from contextual menu choose Add profile division:

Profile division interface window let you define two division parameters: Position of division and Expansion joint for each of profile members.

Position of division is measured from the bottom point of the mullion.

If the defined unit profile length is longer than stock extrusion length Schucal will automatically define the division for this maximum possible length with the option do decrease it.

After entering these values, the interface will sequentially pass to another row of the member on the list. You can define different position of division for each member (they should not overlap). You can enter same or different expansion gap (joint) for each member, you can omit the gap as well.

After confirming the edition process, you can see defined joint in the 3D model represented by triangle node. You can double click it to Edit or right click to Delete or Move individual joint to other position on the mullion preserving the gap offsets between members.

The second type of profile split is Profile Joint.

This is more sophisticated method that not only divides profiles but also adds all structural connectors for the profiles in three possible structural cases and defaults offset and gap parameters.

The method of creating the Profile Joint differs from the way how Profile Division was created. In this case you need to right click the existing façade node represented by white circle and choose command Add profile joint, then later define the position of newly created Profile Joint as a reference offset to this node:

Add profile joint window will appear and there are few settings that needs special explanation.

Use joint for:

• Mullion – All members will be divided: Mullion, Pressure plate, Cover cap
• Transom – Only Pressure plate and Cover cap will be divided.

New joint location is defined as an offset from originally selected node under Distance from joint field. Positive value positions new joint above the node, negative under the node.

All other joint locations refer to main joint location (Distance between joints) with the same rule: positive value – above the joint, negative – below.

You can remove any member from the joint structure by checking off the checkbox next to it.

The article order numbers and cutting lengths are picked automatically by Schucal accordingly to K1013945, depending on the profile part number at the profile joint and the selected joint type. Regardless to this you still can override accessory part number, length, and the quantities.

The most important setting for this type of joint is Joint type.

For the preliminary structural calculation, you can determine how the profile joint should be evaluated for aluminum façades: as a structurally rigid joint, as a cross-section weakness or as a hinged joint.

– Structurally rigid joint:
If an insert profile with sufficient insert length is used as a joint and an identical or larger moment of inertia (Ix) is used as the moment of inertia of the mullion, then this is considered to be a structurally rigid joint. The rigidity of the profile must also exist in the joint. Safety against buckling must be assured. A structurally rigid joint is made by fixing exact, fabricated by customer, steel insert profiles, which sit in the hollow chamber of the profile. The dimensions of the cross-section of the steel insert profiles must be calculated by the structural engineer for the project based on the moment. The insert length (L) can be taken from the drawing K1013945. Once checked by a project structural engineer, it can also be made shorter, depending on the loading.

– Cross-section weakness:
If an insert profile with sufficient insert length is used as a joint and a smaller moment of inertia (Ix) is used as the moment of inertia of the mullion, then this is considered to be a cross-section weakness in the overall system. A partial fixing is therefore generated in the transition from the mullion to the insert profile. The size of the partial fixing varies depending on the relative rigidity between the mullion and the insert profile. When calculating the structural system, the effective length of the cross-section weakness is always assumed to be 500 mm irrespective of the length of the insert profile. The insert length (L) can be taken from the drawing K1013945. Once checked by a project structural engineer, it can also be made shorter, depending on the loading.

– Hinged:
If only a short profile is used as a joint, this type of joint has the effect of a hinged joint in the overall system. Longitudinal and latitudinal forces are transmitted with joints of this type, but no bending moments are transferred. Twisting the two profile ends against one another (bend in the deformation figure) is desirable in connections of this type.

After confirming Add profile joint editor window you will find your new joint in 3D model represented by white circle (red when selected). Under right click action you can change all parameters, delete or relocate to new position.

The gaps of the split are rendered in 3D, but some accessories of the joint e.x. splice insert profiles are not. Notwithstanding these pars are correctly calculated in the Schucal and placed on bulk quantity list, article list, cutting optimization lists and are included in the structural model for Preliminary Structural Calculation.

In the Preliminary structural calculation list, the location of the cross-section weaknesses is identified by two vertical lines in the structural diagram for the support reaction. The position of a hinged joint is identified by a circle.

For mullions with a cross-section weakness, the individual cross sections are detailed with cross-section values in the list. The stresses and the requisite moments of inertia (Wx) are rendered for each cross section. The deflections (f) are rendered for each field of the structural system.