ASDIP WOOD is a structural engineering software for design of wood members. It includes a module for Wood Beam Design based on the latest NDS provisions, which calculates the adjusted design values for the required types of stresses and shows the design ratios accordingly.
But how do you enter the information in the program? How do you check the results? How do you optimize the design in a real example? The following is a step-by-step glulam beam design example using ASDIP WOOD.
Glulam beam design example
As an example, determine the required size of a 24F-1.8E DF stress class glulam, using ASD for the 48-ft single-span beam shown below. Assume dry service conditions and normal temperature range. The design loads are D = 250 lb/ft and S = 750 lb/ft. Consider two cases: a) Laterally braced at 8-ft spacing. b) Laterally braced at supports only.
Glulam beam geometry
In the Geometry tab enter the dimensions given in the statement of the problem, such as the span length = 48'-0" and the support conditions. Select Glulam as the beam type. Let's specify the lateral bracing at 8'-0" spacing first.
The At-a-Glance tab shows a summary of the results, with the most important information, for a quick overview of the design. If a deficiency is identified, it can be further investigated in the other reports which offer a more detailed information.
Specifying the material properties
In the Materials tab specify the material properties. Click on the "Select from Database" button to show the corresponding table from the NDS Supplement. In this case select 24F-V4. The program will transfer the material properties to the template.
ASDIP WOOD generates a detailed presentation of the results, showing step-by-step calculations organized by topic and load combination, with exposed formulas and references to the NDS code. This is excellent for a deep granular check of the design.
Enter the applied loads
Use the Loads tab to enter the applied loads on the beam. In this case the loads are given in the statement of the problem as dead and snow loads loads. Select the option to specify a set of nominal loads at the top of the page, and enter the loads at the corresponding load case tabs. Specify ASD as the design method.
Optimizing the design
The software calculates the adjustment factors for the different design conditions per the NDS. These factors affect the reference design values for the specified material. With this information the program calculates the design ratios in bending, shear, and bearing. Finally it calculates the deflections and compares them against the allowable limits.
In the first case with the lateral bracing at a spacing of 8'-0", the optimal section that passes all checks is a 6.75" x 39" beam. In the second case with lateral bracing at the supports only, the flexural capacity is greatly reduced by the lateral bracing condition, therefore the optimal section that passes all checks is a 8.75" x 36" beam.
ASDIP WOOD includes the design of glulam beams. This step-by-step design example shows how fast the design can be completed and optimized using ASDIP WOOD. The results are shown instantly in both text and graphics format for an immediate granular check.
For our collection of blog posts about concrete design please visit Structural Wood Design.
Javier Encinas, PE
ASDIP Structural Software