Modify Joint

Structural Design User Guide

Modify Sections : Modify Joint

Joints have a number of attributes whose settings allow the user to position and orientate them and to modify the ends of sections connected to them.

A Shelf Angle Joint as defined in the Catalogue (only the Neutral Axis pline is shown for clarity).

Position and Orientation of a Secondary Joint Relative to a Secondary Node

Connect a Joint to the Start of an Attached Section

How the origin plane of the Joint is set with reference to the Owning Section (via the POSL attribute), while its position within the constraints of that plane is set with reference to the Attached Section (by aligning the plines defined by the JLINs of both Joint and Section). That is, with reference to the orientation of the diagram, to move the Joint horizontally change its POSL and vertically change its JLIN. Both the Section and the Joint can be rotated independently by changing their BANGs (the Section rotates about its NA, the Joint about its OPDI).

How the Section End Configuration depends on the Joint to which it is attached

(a wedge-shaped Joint is used to demonstrate the principles).

For the purposes of this user guide, this section shows the user how to add some simple bolted flanges where the beams are attached to the columns. The joint elements (SJOIs in the model explorer) already exist as a result of connecting the sections together. To define each joint’s geometry, set a pointer to the joint specification in the catalogue.

From the SECTIONS tab, in the Modify group, click Fitting. The user is prompted to A Joint Specification window is displayed for the joint to which the picked section end is attached.

Note:

The user can apply a Joint Specification to the connected end of a GENSEC element. Click CE to load the current element (only if the element is a FIXING) to the Joint Specification window.

The method of selection from the available joint specifications is the same as that used to select section profiles. In this case select Column Connections, Column Flange, 6M24_flange and leave all other form settings at their defaults.

Click Properties. A subsidiary Modify Properties window is displayed which allows the user to specify some local dimensional data for the selected type of joint.

For this joint set Thickness of Plt, Dist from TOS, and Dist from BOS. Click OK to close the Modify Properties window and Apply the Joint Specification window to complete the setting of the joint specification. (The geometry of most types of joint can be modified via appropriate entries in a window such as this. How the catalogue has been set up can affect this.)

To see a correct representation of the joint set up the graphical view so that it displays holes (negative volumes) as well as solid items (positive volumes).

On the PROJECT tab, in the Settings group, click Graphics to display the Graphics Settings window.

On the Representation tab, select the Holes Drawn checkbox. Click OK to apply the setting and close the window.

Zoom in close to the beam end to see what the joint looks like. The height and width of the endplate are set automatically from the dimensions of the beam and column, respectively, with adjustments to suit the values entered in the Define Properties window. If the joint dimensions in the catalogue are specified as design parameters whose values are derived from the attached and owning sections. The joint displayed as shown:

The attached beam has been shortened to accommodate the thickness of the plate and the bolt holes in the plate have generated corresponding holes in the column flanges.

The position of the joint relative to the profile of the column (its owning section) is determined by the joint’s position line. To see the effect of changing this. On the SECTIONS tab, in the Modify group, click Section, select Joint Line from the drop-down list to display the Joint Line window.

The displayed Position Line window shows the current setting as either BOS or TOS (depending at which end of the beam the joint is situated). Change this to the opposite setting (that is TOS or BOS), select the Re-trim attached section checkbox, and click Apply. The joint and its attached section end move thus:


		(view rotated)

Reposition the joint correctly, then click Cancel to discard any information and close the Position Line and Joint Specification windows.

Rather than set each joint specification explicitly, the user can apply the specification for one joint to other joints. The facility is used to specify the joint at the other end of the beam which has just been viewed.

.On the SECTIONS tab, in the Modify group, click Joints, select Like Maintain Pline from the drop-down list.

Note:

The user can copy/pick the joints at the end of a GENSEC element or a SCTN element.

The user is prompted to ‘Identify end of section to be copied like’, pick the same section end as picked previously. When prompted to ‘Identify section end to be modified’, pick the other end of the same beam. Press Escape for both of the next prompts.

Zoom in close to the second joint and notice how its geometry matches that of the first joint. The position line settings for the two joints are, however, set automatically to opposite flanges of the column (TOS for one, BOS for the other), to give the correct alignment.

Note:

If the joints were ‘handed’, such as a shelf angle, the user would also see that the second joint has been rotated automatically about its vertical axis to match the start/end directions of the section. The endplate does not show this, on the PROJECT tab, in the Common group, click Attributes, the user is able to see which attributes differ between the two joints. If the user wants to reverse an action, from the Quick Access toolbar, select Undo.