Wood - Database

The Wood Database may be accessed from the Wood tab of the Section Sets spreadsheet by clicking in the Shape field and then clicking , or by clicking the Shape Database button on the RISA toolbar and then clicking the Wood tab of the Shape Database dialog.

Wood Material/Shape Selection

Unlike any other material, the design properties for wood members depends both on the material selection as well as the shape selection. Therefore, the Wood tab of the Shape Selection database contains shape and material selections.

Material Selection

The Material Selection menu reads in material options that are currently listed on the Wood tab of your Materials spreadsheet. You may select one of these existing materials, or click on the Add Material button to open the Create Wood Material dialog which will allow you to add in a new material without having to go to the Materials spreadsheet.

Create Wood Material dialog

The Create Wood Material dialog allows you to create or edit a material that will then be automatically added to your Materials spreadsheet. This allows you to enter/select this information directly from the Draw Members dialog without having to first manually enter the information in the Materials spreadsheet.

Size Selection

Currently there are two ways to define a member size,Select a Size menu or by using the Enter the Size option (typically referred to as Full Sawn).

Note

View Design Properties

Once you have selected the appropriate member size and material, you can click on the View Design properties button to view the un-adjusted wood design values (Fb, Fv, Ft, etc.) for the selected combination. The final adjusted values (Fb', Fv',Ft', etc.) will then be displayed after solution in the Member Detail Reports.

Wood Database Limitations:

Round Shapes

Per section 3.7.3 of the NDS, the design of a round cross section shall be based on the design calculations for a square shape with the same cross-sectional area. Therefore the moment of inertia values will be calculated per the equivalent square shape, not the round cross section. However, the section modulus value, S is calculated per the actual round shape.

Glulam Databases

The program includes five tables of available glulam materials: NDS Tables 5A - 5D and CSA O86 Table 6.3. The values in NDS tables 5B & 5D depend on the number of laminations in the glulam. Therefore you will see three listings (2 Laminations, 3 Laminations, or 4 Laminations) for each material. If you have a custom material that is not available from these lists, you can always enter your appropriate design values as a Custom Wood Material for use in your model.

Note:

Mechanically Graded Lumber

Mechanically graded lumber grades (MSR & MEL) are available for use with the ANSI/AWC NDS-2015 and the CSA O86-2014 design codes. Older versions of the design codes will not support design of mechanically graded materials from the program databases. However, you can always enter the properties as a Custom Wood Material to get the design calculations for these materials in older code versions.

In order to assign a mechanically graded lumber material, you must select both the species and then the mechanical (MEL or MSR) grade. The species selection determines the shear capacity and compression perpendicular to grain capacity design values.

See Footnote #2 from NDS 2015 Table 4C which says that all species from NDS 2015 Table 4A are applicable. See clause 6.3.2 from CSA O86-14 which says that specified shear strengths shall be taken from CSA O86 Table 6.3.1A.

The other design values are defined per the mechanical grade. See NDS 2015 Table 4C and CSA O86-14 Tables 6.3.2 and 6.3.3.

Structural Composite Lumber (SCL)

Each SCL manufacturer has documentation of their proprietary material design values. Because these are updated so often, RISA-3D relies instead on the design data from approved product reports (APA and ICC-ES) to build the material databases:

Footnote Limitations:

Each of the above reports includes tables with design values which were used to create the RISA-3D and RISAFloor SCL design property material databases. However, due to the difficulty of design variation, the following limitations are present:

Alternatively, you can always enter the appropriate design values, per the applicable footnotes, as a Custom Wood Material.

Design Values

The design properties may be verified by clicking on the View Design Properties button on the Properties tab of the Member Information dialogs.

The values are as follows:

Currently the program only designs using the Joist properties of the SCL materials. This assumes that the loading is always on the small dimension side of the member. In a future version we will be taking the Plank values into consideration as well. In the meantime you can always enter the appropriate design values from these tables as a Custom Wood Material for use in your model.

Note:

Custom Wood Sizes:

If you would like to enter explicit dimensions of a member or if the member is "Not Dressed", the member must be designated as a "Full Sawn" member by checking the Use Full Sawn Size check box and entering the exact dimensions of the member in the boxes below.  This applies to regular wood species, custom wood species, Structural Composite Lumber (SCL), and Glu-Lam members. The member thickness should be entered in the box on the left and the member width should be entered in the box on the right.