Frame connections describe the positioning relationship between member systems. This positioning relationship defines the member orientation and offset of the supported member in relation to the supporting member. Two frame connections are placed when you place the member system, one at each end. Because frame connections define relationships between member systems, the frame connection might prevent you from moving a member. The types of frame connections are:
An align frame connection places the end of the supported member system at the intersection of three surfaces that you define. You can define offsets from all three surfaces. This frame connection is useful, for example, when you want a column to move with a wall or bulkhead on a lower floor or deck.
An axis along frame connection aligns the cardinal point on the supported member system with the cardinal point on the supporting member system. Use this frame connection when the member systems are different types (a beam framing into a column for example). Using this frame connection, the beam will slide along the length of the column, but will not cause the column to lengthen or shorten. You can specify an optional offset in all three directions.
An axis end frame connection aligns the cardinal point on the supported member system with the cardinal point on the supporting member system. Use this frame connection when both member systems are of the same type (both members are columns, or both members are beams). If you move one member system end, this frame connection automatically moves the other member system end to maintain the connection. You can specify an optional offset in all three directions. Use this frame connection for column splices.
The Axis End frame connection makes the members mutually editable. For example, if you move one member, the other member will extend or shorten to maintain the connection. Because of this, if you change the permission group of one member, the software automatically changes the permission group of the other member to match.
A centerline frame connection uses the supporting member's centerline to position the supported member.
A flush frame connection uses the supporting member's top and bottom extent to position the supported member. The supported member typically lies within the body of the supporting member.
A seated frame connection uses the supporting member's top or bottom extent to position the supported member. The supported member typically rests against the supporting member, but can be offset.
A gap connection defines offsets between members to provide clearance for welding or simply as a work point adjustment. Smart 3D can calculate the offset either axially along or radially around the support member. You must use the More... option and select the gap frame connection that you want to use. The software will not pick a gap frame connection when using the By Rule connection option.
There are three members in a gap frame connection:
The target member is the member always to move and is the owner of the frame connection. The target member is shown as blue in the figure below.
The primary member is the member to which the other two members are attached. The primary member is shown as red in the figure below.
The secondary member is the third member in the joint. The software does not require the secondary member to be in the same plane as the target member. The secondary member is shown as orange in the figure below.
There are four gap frame connections available:
Radial Gap Single - Moves the target member radial around the primary member. The gap is measured between the target and the secondary member.
Radial Gap Both - Moves two target members radial around the primary member. The gap is measured between the two target members. Both target members' frame connection on that member end must be Radial Gap Both.
Axial Gap Single - Moves the target member axial along the primary member. The gap is measured between the target member and the secondary member.
Axial Gap Both - Moves two target members axial along a primary member. The gap is measured between the two target members. Both target members' frame connection on that member end must be Axial Gap Both. For example, for chevron bracing you must define the Axial Gap Both frame connection for the ends of both braces for which you want define the gap. Then edit the properties of the Axial Gap Both frame connection to define the needed gap distance. The software recognizes the other brace frame connection is also an Axial Gap Both frame connection and moves both brace ends half the defined gap distance to achieve the gap.
A surface connection specifies the relationship between a supported member and the surface of the supporting object.
Surface-Default - Connects a member to a slab, wall, or plate.
Surface-Plate System - Connects a member to a marine plate system created in Molded Forms. The software never selects this frame connection when the By Rule option is selected. You must manually select this frame connection for use.
A tangent connection specifies a relationship between a supported member (1) and a supporting member (2). A circle, whose radius you define (3), is projected out from the centerline of the supporting member. The supported member is then made tangent to that circle. You can also control the plane of the tangent circle.
Vertical Corner Brace
A vertical corner brace connection specifies the location of a vertical brace that frames into a column-beam corner. You can define offsets in the X, Y, and Z-directions, and there are six work points to select from when using this connection.
An unsupported connection allows you to place a member end in free space. The top ends of columns have the unsupported frame connection.
Members connected to other members using the Axis-Along, Seated, Centerline, Flush, and Tangent frame connections use the Ratio option for Position Rule to maintain the position relationship between the supported and supporting members.
A Surface frame connection maintains the current direction of the member if the opposite member end (regardless of the frame connection at that end) is moved.
Selection of Frame Connections
During the placement of linear members, you can have the software determine frame connections by selecting the By Rule option. The software uses these rules based on supported member type category, type, permission group, and geometry as it connects to the supporting member to select frame connections:
When the member connects to non-member objects, the software selects the "Unsupported" frame connection unless the non-member object is a surface, in which case Surface-Default is chosen.
When a member connects to a single member, the software selects Axis Along unless:
The two members are end-matched and either the member being placed is a Brace member type or the member types and categories are the same, then the software selects Axis End.
The member being placed has a member type of Girt or Purlin and the two members are not parallel, then the software selects Seated-Top.
When placing a member and you select another member's frame connection as the end point, the software reads both the frame connection's member and its optional supporting member. If the member being placed is coplanar with those two members, then the software selects Vertical Corner Brace- WP2.
When placing a member and you select a split connection as the end point, the software reads the two members related to the split connection. If the member being placed is coplanar with those two members, then the software selects Vertical Corner Brace-WP2.
Locating Frame Connections
Frame connections do not display in the model except during member placement. However, if you set the Locate Filter to Frame Connections, you can locate and select frame connections for review and editing. Frame connections are located near the ends of member systems and appear as circles when you move the cursor over them. In addition, if you have a member part selected, press CTRL + END to switch the selection to the part's frame connections.