ACA Structural Member Styles - Part 5

First Article in the Series (Structural Member Catalog)
Previous Article in the Series (Manually Created Structural Member Styles)

Structural Member Contextual Ribbon Tab
In addition to the accessing the various Structural Member tools on the Manage ribbon tab, from the flyout of the Style & Display panel, once you have at least one Structural Member in your drawing file, you can select a Structural Member and access the Structural Member Catalog, Structural Member Wizard and Insert Member Shape tools as well as a tool to open the Style Manager filtered for Structural Member Styles from the Structural Member contextual ribbon tab, shown below in it ACA 2010 incarnation.

ACA Structural Member Styles - Part 4

First Article in the Series (Structural Member Catalog)
Previous Article in the Series (Manually Created Structural Member Shapes - Fun Facts)

Manually Created Structural Member Styles
As we have seen in the first three articles in this series, there are a number of opportunities for having AutoCAD^® Architecture generate a Structural Member Style automatically. When you need a Structural Member Style that has a single Structural Member Shape for both the start and end shapes, with no offsets, then you will want to take advantage of the automatic features. Even when you have a more complicated need, starting out by generating the style automatically may help save a few steps along the way. When the automatically generated styles will not meet your needs, you will need to either create a new style or edit a generated style. This article will take a look at some of the things you can do with manually created Structural Member Styles.

Structural Member Geometric References
Understanding how ACA labels the axes of a Structural Member is key to avoiding confusion when specifying the parameters we are about to examine. The diagram below shows the polyline from the High Detail shape for the W24x76 shape, inserted "as created" relative to the World UCS. The blue UCS Icon in the lower left corner shows the axes of the World UCS. For this shape, the insertion point was defined at the geometic midpoint of the shape. The X-axis of a Structural Member runs along the length of the member; the positive direction is from the starting point to the ending point. The Y-axis and the Z-axis are perpendicular to the X-axis. For a shape with no rotation, the positive Y-axis is the same as the World UCS positive X-axis of the shape and the positive Z-axis is the same as the World UCS positive Y-axis.

Confused? Keep the diagram above handy when editing the parameters of a Structural Member Style.

Another thing to keep in mind when setting up your Structural Member Style is that the final position of the shape(s) you define will depend upon the Justify property (found in the Dimensions category on the Design tab of the Properties palette) of the Structural Member. Baseline will place the insertion point of a shape at the starting point of the Structural Member, if no offsets have been applied to the shape. Middle Center will put the geometric midpoint of the shape(s) (with offsets, rotations and mirror applied, as applicable) at the starting point of the Structural Member, for the Medium Detail and High Detail geometry. Applying different offsets to the start and end shapes will also affect the calcuation of the geometric midpoint. Most Structural Member Styles will not need to be that complex; should you need to create one with that level of complexity, you will want to start as simply as possible, checking the effects of each edit before making the next one.

Automatic Structural Member Style
First, we will look at the automatically generated W24x76 Structural Member Style that was created in Part 1, to get an understanding of the inner workings. With a drawing open in which the W24x76 Structural Member Style has already been created, on the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool to open the Style Manager dialog. In the left pane, expand the Architectural Objects and Structural Member Styles nodes and select the W24x76 style. [Make certain you are under the Structural Member Styles node, and not the Structural Member Shape Definitions node.]

The General tab of a Structural Member Style has the usual features found when editing other styles and definitions. You can edit the Name, provide a more detailed Description, add a Keynote, attach Notes and attach Property Sets. In addition, you can specify whether or not objects of this style can act as boundaries for associative Spaces. As you can see below, an automatically generated style only has the Name you specified at the time of generation; you will have to add the Description, Keynote, Notes and/or style-based Property Sets that you want.

The heavy lifting for a Structural Member Style takes place on the Design Rules tab.

The W24x76 shape has a single Component, called Section. Structural Member Styles can have multiple Components; the display system allows for display control over a maximum of ten. The Add, Copy and Remove buttons in the lower right side of the Design Rules tab allow you to add a Component, add a copy of an existing Component or remove an existing Component, respectively. You can give each Component a name of your choosing, which can help when editing the display properties at the style- or object-override levels. Each Component has two sets of parameters associated with it, one set for the Start Shape and one set for the End Shape. If you are not seeing these, then the button labeled Hide Details in the image above will read Show Details; click it to show the parameters.

• Name The name parameter specifies the Structural Member Shape Definition assigned to this component, selected from a drop-down list of the shapes defined in the current file.
  
  Most times you will want to have all of the shapes you need defined before creating the Structural Member style. If the End Shape is to be the same as the Start Shape, and have the same Scale, Mirror, Rotation and X, Y and Z Offsets as the Start Shape, choose the same shape name, preceeded by an asterisk, from the End Shape Name drop-down. This will lock out those properties for the End Shape and assure that any changes made to the Start Shape will also be made to the End Shape. (This is the initial default when adding a new Component.) You can still specify the Relative to and Node parameters for the End Shape. If you want to use the same shape, but change anything other that Relative to and Node, choose the shape name without the initial asterisk from the End Shape Name drop-down list.
  
• Relative to The Start and End Shapes can be placed relative to either the very Start of the Structural Member or the very End of the Structural Member, by selecting either Start or End from a drop-down list. For an automatically generated, single-shape style, the style will be based on a single segment member, with the Start Shape set relative to the Start and the End Shape relative to the End.
• Node The Node parameter is an integer that indicates the Node number (relative to the Structural Member end specified in the Relative to parameter). A single-segment style has two Nodes, 0 and 1. Multiple-segment styles will always have one more Node than the number of segments. When Relative to is set to Start, the 0 Node is the first Node of the Structural Member, the 1 Node is the second Node, et cetera, with the highest number Node being the last Node. When Relative to is set to End, the numbering is reversed, with the last Node being the 0 Node, the second-to-last node being the 1 Node, et cetera, with the highest number Node being the first Node. That is why, in the W24x76 style, both the Start Shape and the End Shape are at Node 0. These are not the same Nodes, since the Relative to settings are Start and End, respectively.
• Scale You can apply a real-number scale factor to the shape, to uniformly increase or decrease the size of the shape from what is defined in the Structural Member Shape Defintion. This can allow a single definition to serve multiple sizes, when a single scale factor works for resizing the shape.
• Miror The Mirror parameter has a drop-down list with two choices, Yes or No. Yes will mirror the shape about the Z-axis of the Structural Member.
• Rotation The Rotation parameter takes a real-number angle value (in the drawing's current angle units), and rotates the shape about the shape's insertion point.
• X Offset The X Offset is a real number distance value (in the drawing's current linear units) and specifies an offset along the Structural Member's longitudinal axis from the Node at which the shape is placed. Positive values move the shape in the direction from the starting point toward the ending point.
• Y Offset The Y Offset is a real number distance value (in the drawing's current linear units) and specifies an offset along the Structural Member's Y-axis. (Refer to the first image above.)
• Z Offset The Z Offset is a real number distance value (in the drawing's current linear units) and specifies an offset along the Structural Member's Z-axis.

The final parameter of each Component is the Priority. You can ignore this for single-component styles or for single-segment (two nodes, 0 and 1) styles. Priority is used to control the mitering of components meeting at a common node. Components with the same priority will miter with each other, even if they do not intersect (provided there are no X offsets); components with different priorities will not. The Priority parameter can also be used to limit the justification of a structural member to just those components with the highest priority. This is done using the Justify components property on the Design tab of the Properties palette, found under the Basic category and Dimension sub-category. You can have the justification based on All components, or Highest priority only components.

Manual Structural Member Style Examples
The Start and End Shapes can be the same, as in the W24x76 style examined above, but they need not be. If different shapes are specified, ACA will transition from the Start Shape to the End Shape over the length of the component. For example, if the Start Shape is a 24x24 square and the End Shape is a 12" diameter circle, both with insertion points at the center of the shape, and added without any translations or rotations...

...you get something that looks like this.

Making a copy of the W24x76 Structural Member Style, changing the End Shape Name to W24x76 (without the asterisk) and applying a 90-degree rotation to just the End Shape...

...results in a Structural Member that does this.

In the W24x76 Double Structural Member Style shown below, I started out with a copy of the W24x76 Structural Member Style, selected the Section component and used the Copy button to create a copy of the Section component. I renamed the copied component to Section2 and then added Y Offsets of -9" to the Section component and 9" to the Section2 component.

This creates a double column.

Next Article in the Series (Structural Member Contextual Ribbon Tab)

ACA Structural Member Styles - Part 3A

First Article in the Series (Structural Member Catalog)
Previous Article in the Series (Manually Created Structural Member Shapes)

Manually Created Structural Member Shapes - Fun Facts
Here are a few additional items of interest related to Structural Member Shapes that I have discovered as I was experimenting for the next main article in this series.

1. In order to maintain maximum sanity, set the UCS to World and use the Plan command to orient the screen so that the X-axis is left and right, with positive in the right direction and the Y-axis is up and down, with positive in the up direction. In limited experimentation with a single, 2D polyline as the shape, it appears that the shape will be imported with the World Y axis (or its equivalent, if the plane of the polyline is not parallel to the World X-Y plane) running vertically in the dialog, with positive being up. For example, if you start with the World UCS and rotate the UCS about the Z-axis, that rotation is ignored when bringing the shape into the dialog. When selecting the insertion point, the values of the point selected in the current UCS are used, but are applied relative to the World UCS. In other words, ACA does not translate the insertion point picked from the current UCS to the World UCS, so the insertion point can end up in a very unexpected location, unless it is 0,0 and 0,0 is the same in both the World and current UCS. Someone with a better head for three-dimensional geometry than me may be able to deal with this, but for me, best practice will be to start out with UCS set to World and the screen oriented to the Plan view of the World UCS.
2. 2/10/2012 UPDATE: The following comment only applies to a Structural Member Style that has a single Structural Member Shape assigned to a single component. Insertion points do matter when more complex styles are created.
   2/10/2012 UPDATE 2: Insertion points always matter. The effects I was seeing and which prompted the following comment were due to the fact that all of the Structural Members I had created had their Justify property set to Middle Center, which places the geometric midpoint of the overall assembly at the starting point of the Structural Member. Setting the Justify property of the member to Baseline will place the insertion point of the shape at the starting point of the structural member, provided there are no Y Offsets or Z Offsets. The part of the comment regarding the Low Detail insertion point remains valid, however. Wherever the Medium Detail insertion point of a shape ends up, that is where the Low Detail insertion point for that Shape will also be.
   When assigning a Structural Member Shape to a Structural Member Style, the insertion point selected for the Shape will not necessarily be on the longitudinal axis of the Structural Member. For Medium Detail and High Detail, the shape is intially aligned at the "midpoint", with the midpoint being the point whose X-coordinate is the average of the shape's smallest and largest X-coordinate values and whose Y-coordinate is the average of the shape's smallest and largest Y-coordinate values. Even if you intentionally offset the High Detail insertion point from the Medium Detail insertion point, both will come in with the midpoint of each at the longitudinal axis of the Structural Member. The selected insertion point does matter for the Low Detail geometry, which does not have to be a closed shape and can have lines and arcs. Low Detail geometry will be placed such that its selected insertion point remains aligned with the selected insertion point of the Medium Detail geometry.

Next article in the series (Manually Created Structural Member Styles )

ACA Structural Member Styles - Part 3

First Article in the Series (Structural Member Catalog)
Previous Article in the Series (Structural Member Wizard)

Manually Created Structural Member Shapes
For those times when you want to create a Structural Member Style that does not have a standard cross-sectional shape, you will need to manually create the Structural Member Shape Definition and then add it to a Structural Member Style.

If you enjoy working from prompts on the Command: line, then you can use the
-AecsMemberShapeDefine command to do so. I find it easier to use the Style Manager, so that is the method that will be shown here. Before we dive into creating a custom Structural Member Shape Defintion, lets take a look at one, so we understand how it works. Structural Member Shapes support three levels of detail: Low Detail, Medium Detail and High Detail. Low Detail graphics can consist of lines, arcs, cirles or polylines. The image below shows the W24x76 Member Shape Definition (created from the Structural Member Catalog in Part 1 of this series) on the Design Rules tab in the Style Manager. This tab features a viewer pane that shows the cross-sectional geometry associated with this shape. Selecting Low Detail in the upper right corner highlights the Low Detail geometry in green; the Medium and High Detail geometry remains visible in the viewer, in white. A small "x" indicates the insertion point for the shape. As always, click on any image to see a full size version. If your browser replaces the current page with the image, use the Back button to return here.

Low Detail is intended for small-scale drawings, such as overall floor plans, where representing a wide-flange shape by three lines would be an appropriate level of detail.

The Medium and High Detail graphics have to be closed polylines, splines, elipses or cirlces. You can have more than one of these objects, but they cannot intersect each other, nor can they self-intersect. The Medium Detail graphics for the W24x76 Member Shape Definition consists of a single closed polyline showing the overall size and thickness of the web and flanges, and is appropriate for medium scale representations.

The High Detail graphics for the W24x76 shape also consist of a single, closed polyline, but differ from the Medium Detail graphics in that the fillets between the flanges and the web are shown. This would be appropriate for a large scale representation of the shape.

Each Structural Member Shape Definition must have Medium Detail geometry assigned. The Medium Detail geometry will be used for shapes where geometry is not specified for the Low Detail and/or High Detail conditions. For simple shapes, such as a circular column, assigning geometry to just Medium Detail may be appropriate. A square shape (with a side of 1'-0" for imperial units or 300 mm for metric units) is initially assigned when you create a new Structural Member Shape Definition, so be certain to replace that with the desired geometry. In the out-of-the-box Display Representations for Structural Members, the Structural Member Shape is used for the "Visible Comp n", "Hidden Comp n" and "Component n" Display Components, where n is an integer from 1 to 10. (Structural Members offer display control for up to 10 different components.) The Display Representation that have "Low" in the title use the Low Detail shape. The Display Representation that have "High" in the title use the High Detail shape. All others use the Medium Detail Shape. ("Logical" is a special case, which does not display any of the shapes.)

In the following example, a Structural Member Shape Definition will be created for eventual use in a Structural Member Style that will represent an architectural column cover. A simple circle will be used to represent the cover for Low Detail. In Medium Detail, two circles will be used to show the outside and inside faces of the cover. For High Detail, a closed polyline will represent the detailed profile of the cover. You will need to create the necessary geometry for your shape first, then assign it to a definition.

On the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool. In the left pane of the Style Manager, expand the Architectural Objects and Structural Member Shape Definitions nodes under your current drawing and then select the Structural Member Shape Definitions node. In images below, I have selected the Filter Style Type tool (funnel icon) in the toolbar at the top of the Style Manager dialog to show only Structural Member Shape Definitions. In the right pane, right click and choose New from the context menu. Enter an appropriate name for the new definition - the example definition is called Fluted Column Cover.

In the left pane, select the name of the new definition. Select the General tab in the right pane, and add a more detailed description and, if you want, notes for this definition.

In the left pane, select the Design Rules tab. Take a look at the upper right corner, in the Shape Geometry area. The caution icons in front of the Low Detail and High Detail choices indicate that no geometry has been assigned. As mentioned above, there is already default geometry assigned to Medium Detail for the shape, and the preview window shows the default square shape.

To assign the right geometry for Medium Detail, make certain that Medium Detail is selected in the Shape Geometry area, and then select the Set From button. This will temporarily hide the Style Manager dialog, and, at the Command: line, prompt you to "Select a closed polyline, spline, ellipse, or circle for an outer ring:". Select the outermost geometry ("ring") for Medium Detail.

After selecting the outer ring, you will see the prompt "Insertion point or [Add ring/Centroid]:". Selecting an insertion point or choosing the Centroid as the insertion point will end the ring selection process. In this example, Medium Detail has a second ring, so choosing the Add ring option is appropriate. Continue to choose the Add ring option and select rings until all rings have been selected, and then select an insertion point or use the Centroid option to set the insertion point at the centroid of the selected geometry. This will bring the Style Manager dialog back on the screen, with the newly selected geometry displayed in the preview window.

If you have Low Detail and/or High Detail geometry for your shape, select the Low Detail or High Detail item in the Shape Geometry area and repeat the process of selecting the Set From button and following the prompts. Low Detail will not ask for an outer ring, just lines, arcs, circles or polylines and will not offer Centroid as an option for selecting the insertion point. Make certain that the insertion point for each detail level is the same, relative to the selected geometry. The image below shows the completed Fluted Column Cover Structural Member Shape Definition, with High Detail selected.

You can create a single-shape Structural Member Style that uses your new shape by selecting the Create Style button on the Design Rules tab. The default name for the Structural Member Style will be that of the Structural Member Shape Definition; you can edit the name if you want.

The image below shows an instance of the generated Fluted Column Cover Structural Member Style with the Masonry.Stone.Travertine.Cream Material Definition applied, in Realistic View.

Next article in the series (Manually Created Structural Member Shapes - Fun Facts )

ACA Structural Member Styles - Part 2

First Article in the Series (Structural Member Catalog)

Structural Member Wizard
Sometimes you need a Structural Member Style for a standard shape which is not in the Structural Member Catalog. Or perhaps it is early in the design process, and you have an approximate size for a steel shape, but not an exact size. Rather than pick an exact section, you would like to create a generic member as a placeholder until the structural design is finalized. For these cases, the Structural Member Wizard can speed the creation of the necessary Structural Member Shape Definitions and Structural Member Styles. Access the the Structural Member Wizard on the Manage ribbon tab, by selecting the title of the Style & Display panel to expand the panel and choose the Structural Member Wizard tool on the flyout.

The Structural Member Style Wizard dialog has three "pages". On the first page, you select the Member Shape, from a list of standard shapes in three categories: Concrete, Steel and Wood.

The left pane of the dialog shows a schematic sketch of the standard shape selected, and indicates the dimensions over which you will have control. The illustrations that follow are based on the Steel, Wide Flange (I) shape, but all work in a similar manner.

With the desired member shape selected, select the Next button to advance to the second page, where you will enter the dimensions that will be applied to the Member Shape to be generated.

Most of the values will be shown on the sketch in the left pane; any that are not, such as E - Weld Radius, should be evident from the description. In this case, the Weld Radius is the radius of the fillets between the web and flange. When the values are set as desired, select the Next button to move on to the third page.

On the third page, you specify a name for the Structural Member Shape Definition and Structural Member Style to be created. The page also gives you a summary of the shape type and associated parameters, with the values you entered. Review these to verify that they are correct. You can use the Back button to return to either of the previous screens and make any changes, if needed. When you are satisfied that all values are correct, select the Finish button on the third page to generate the definition and style.

You can check what was created by opening the Style Manager (on the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool). Under the current drawing in the left pane, expand the Architectural Objects node, and then expand both the Structural Member Shape Definition and Structural Member Styles nodes. You will find that a shape definition and a style using that shape definition have been created using the name you specified and the Member Shape selected and the geometric information entered in the dialog.

Next article in the series (Manually Created Structural Member Shapes)

ACA Structural Member Styles - Part 1

AutoCAD^® Architecture provides a number of ways to create Structural Member Styles. This series of articles will take a look at the various options.

Structural Member Catalog
If you are trying to create a Structural Member Style for a standard steel section, or for a typical concrete or timber member, you will want to make the Structural Member Catalog your first stop. The parameters for standard structural members, both Imperial and Metric, are already stored in the Structural Member Catalog, waiting for you to make use of them. Access the the Structural Member Catalog on the Manage ribbon tab, by selecting the title of the Style & Display panel to expand the panel and choose the Structural Member Catalog tool on the flyout.

The Structural Member Catalog is composed of three main sections.

1. The upper right pane will display an image related to the part of the catalog you are currently viewing.
2. The left pane is the navigation pane. By expanding the appropriate nodes in the tree structure, you can drill down to the part of the catalog that contains the member of interest.
3. The lower right pane displays the data associated with the node selected in the left pane. While in the upper level nodes, you can also double-click on an item in the lower right pane to open that node and see its contents.

For example, suppose you needed to model a W24x76 steel beam. In the left pane, expand the Imperial, Steel, AISC and I-Shaped nodes, and then select the W2n, Wide-Flange Shapes item. You will see a list of the AISC wide-flange steel shapes from W21x44 to W27x258 in the lower right pane. Scroll down in that pane until you see the W24x76 member.

Now comes the really hard part. Right click on the the W24x76 member, and choose the only item on the context menu, Generate Member Style.

In the Structural Member Style dialog, give the Style a name. The name defaults to the designation for the member, in this case W24x76.

Once you are satisfied with the name, click OK. You can create as many additional Structural Member Styles as you need. When you are finished, close the Structural Member Catalog by clicking on the "X" in the upper right corner.

You can check what was created by opening the Style Manager (on the Manage ribbon tab, on the Style & Display panel, select the Style Manager tool). Under the current drawing in the left pane, expand the Architectural Objects node, and then expand both the Structural Member Shape Definition and Structural Member Styles nodes. You will find that a shape definition and a style using that shape definition have been created using the name you specified and the geometric information stored in the catalog.

Next article in the series (Structural Member Wizard)