You can place linear and curved members. All linear members are placed using Place Linear Member Systems . All curved members are placed using Place Curve Members . Both commands provide options for selecting member type category, type, section name, cardinal point, and other options during placement.
In addition, the software provides several member placement productivity commands in the Structure task that, depending on what you are doing, might be a better choice than Place Linear Member System. For example, to place a column at each grid intersection in one operation, use Place Columns at Grid Intersections . If you want to place cross bracing, use Place Bracing . Use Place Framing Members to place secondary framing members in a bay. If you want to place support members around a vertical vessel, use Place Vessel Supports . Before you start placing members however, there are concepts that you need to know.
Although not required, we recommend that you place grid planes, elevations planes, and grid lines using the Grids task before placing structural members.
Standard Member Systems
Member systems are logical collections of member parts that maintain the design basis and physical alignment of the member parts for analysis, design, and manufacturing. For example, in vertical cross-bracing, typically one of the vertical braces is split into two parts so that it does not interfere with the other vertical brace in the cross. The member system for that split vertical brace maintains the co-linear alignment of the two parts when you move either outside corner of the vertical brace. Another example of a member system would be a jacket leg. The leg is comprised of different parts, including cans that have different cross-section sizes, but you want the entire leg to move as a single member. Use Place Splits to split member systems into member parts.
Member systems connect to other member systems using Frame Connections. For more information, see Frame Connections.
Member parts are children of a standard member system and represent the physical parts in the model. Member parts connect logically to other member parts using assembly connections. For more information, see Member Assembly Connections.
Designed members are composed of individual plates in the same fashion as a standard rolled member. For example, a designed member with a W-section has a plate for the top flange, a plate for the web, and a plate for the bottom flange. These plates behave just like all other plates in the model, which means you can detail and manufacture the plates in the Structural Detailing and Structural Manufacturing tasks. You can even edit the properties of the individual plates to adjust the plate thickness, for example, without affecting the designed member's cross-section. Because designed members are composed of plates, you can place members in the model that are prismatic, tapered, and non-prismatic. Use designed members to place tapered, can, cone, haunch, and other specialty members in your model. It is important to know that if a designed member is placed in a lapped configuration (for example, as a plate stiffener) on a plate system, no logical connections are created along the designed member’s toe trace. If needed, the logical connections must be placed manually. Sections for designed members are delivered in two section libraries: Built-Up-English and Built-Up-Metric.
Member Type Category and Type
Member categories are broader groupings of member types. For example, the software delivers a member type category called column. In the column type category are member types called column and stud. When placing a member, you have to select a member type category and a member type. You can define your own member categories and member types by editing the Structural Member Type select list in the Catalog task. Refer to the Catalog User's Guide for more information.
Member Local Coordinate System and Orientation
The software uses the following convention to determine the local coordinate system of a member. The member's local x-axis is along the member axis from member start to member end. The member's local z-axis is the strong axis of the member cross-section. The member's local y-axis is determined by the right- hand-rule using the local x- and z-axes.
When placing members, the software sets the local z-axis of the member parallel to the global Z-axis by default. However, if you rotate the member such that the local x-axis of the member becomes parallel to the global Z-axis, then the software switches the local z-axis of the member to be parallel to the positive global X-axis. When you select a member part, the software indicates the member's x- and z-axes with arrows that display at the member part start end.
Discrete or Contiguous Placement Methods
When placing members in the model, you can use either discrete placement or contiguous placement. The discrete placement method requires you to define both the start and the end points of the member, which is useful when placing columns. The contiguous placement method uses the end point of the previously placed member as the start point of the next member. This method is useful when placing multiple beams, because in most cases the end of the previous beam is where you want to start the next beam.
The Start and End commands on the ribbon are used to toggle between placement methods.