Number of Joints (NOFJ)

The automatic joint specification has a number of headings to help automatically choose the correct joint on a connection. One of these is Number of Joints (NOFJ).

When a connection is made and there is no other connection at the same point, a JLDATU is created on the GENSEC, containing a PLDATU, which contains the FIXING. If the automatic joint selection option is turned on, the joint details are created automatically.

In the example, a bolted joint has been created automatically. In this case, the number of joints is 1, as there is one PLDATU in the owning JLDATU.

If another beam is created on the other side, the PLDATU is created under the same JLDATU and the number of joints is 2, as there are two PLDATUs in the owning JLDATU.

In many cases the number of joints does not matter and can be ignored. In this case, it does make a difference as both the connections cannot be bolted.

By default, if there is one connection, a bolted connection may be required, but if there are two connections, a different connection is required. This is when a NOFJ heading can be added to the automatic joint specification.

If the option is set to 0,0 the number of joints is ignored. In this case, if there is one joint, a bolted fixing is required (setting 1,1), but if there two joints, then a welded fixing is required (setting 2,2).

By creating a new row in the automatic joint specification and adding the NOFJ as described, it is possible to select a different joint detail based on the number of joints.

STRUCL Attribute

In the example, a bracing has been added which creates a PLDATU in the same JLDATU.

There are two joints, but in this scenario a bolted connection is still required. If the STRUCL attribute of the beam and the bracing are different then the NOFJ is still only regarded as one, as the number of joints function only assesses the number based on the connected items STRUCL. Some projects may not use STRUCL, and all GENSECs have an unset STRUCL. In this case, the beam connection is set incorrectly to a welded connection, by setting the STRUCL of one of the GENSECs to BRACING or BEAM, the correct bolted connection is created.