After the verification of a complex member you can select and verify elements connecting individual member chords. Analysis of chord connections in a complex member is run by clicking the Lattice button in the Detailed Results dialog. The Connection of Chords dialog consists of two tabs containing data about connectors in planes XY and XZ needed for calculations. For each of the planes the analysis is carried out independently.
Depending on the earlier defined type of chord connection in individual planes (battens or lattice selected in the Complex Section dialog) possible solutions for connection details are automatically provided.
There are the following analysis types available for battens:
- welded connection to member: fillet weld
- welded connection to member: butt weld
- bolted connection to member
for lattice:
- welded connection to member: fillet weld
- bolted connection to member.
Verification of the chord connection includes a resistance check of the element connecting the chords (batten resistance, compression with buckling of diagonals and posts) and resistance check of welds (bolts) connecting battens (lattice) with a member section.
While defining parameters of a batten connection with a column section, verification of basic geometrical parameters of the connection is performed. For a fillet weld connection the program checks allowable dimensions of fillet welds. It is assumed that the fillet weld takes the shape of letter C. If the length of horizontal parts of a weld is not greater than 40 mm, then these parts are not considered in calculations (only vertical parts of the weld are considered in calculations).
The geometrical verification of the distribution of bolts is performed in a batten connection and if data is incorrect. For the butt weld it is assumed that the weld length equals the batten height, while the thickness is a lesser value of the batten thickness and the thickness of flanges of the column chords.
Verification of a connection of lattice elements with the column section is carried out in a simplified manner. For fillet weld connections, the total length of welds connecting the lattice with the column section is required. The center of gravity of the weld system is collinear with the member axis (the system is subjected only to shear without considering possible eccentricities). For bolted connections, the section axis and the axis of bolt positions are collinear. Therefore, load capacity of such a connection is a total of capacities of all the bolts included in the connection.
To start calculations of chord connections, click the Calculations button. The Detailed Results dialog shows the additional tab Battens /Lattice which contains the most important results of connection verification (entire data and all verification results in a table form).
Click the Save button to save chord connections together with a member. After defining the connection of chords in a member, during the next verification, you can obtain complete results together with the full verification of the connection (without the need to open the Connections of chords dialog again). Delete the results by clicking the Delete button.
Information about chord connections in a column is linked with a specific section and a specific lattice type defined during member parameter definition. If a different section is ascribed to a member or if a lattice definition is modified, then information on chord connections is removed.
You can also define chord connections for several members simultaneously. It may be done in two ways:
After group verification:
The result of verification of a member group is indication by the program of the group's representative with the greatest ratio. After opening the Detailed Results dialog for this member, you can design a connection of member chords. If the Save button is clicked after designing this connection, then definition of this connection is ascribed to all the members included in the verified group. Take note, however, that it is possible only on condition that for all the members the same section and appropriate lattice types have been defined. From this moment on, verification of all members in a group will be carried out taking account of the chord connection check.
After group design:
The result of verification of a member group is an indication of the sections among member families defined for calculations, which satisfy the code conditions. After opening the Detailed Results dialog for a selected section, you can design a connection of chords.
The designed connection may be ascribed to a member on condition that the currently considered section is simultaneously assigned to the analyzed member group. If the Save button is clicked, then the section will simultaneously ascribe the chord connection (designed for this section) to the member group. Verification of all members in a group will then be carried out while taking account of the chord connection check.