1. Beam Design

2. Anything wrong here?

3. Discussion Topics--Beam Types
1--Solid timber beam
2--Built-up dimensional lumber beam
3--Glued Laminated beam
4--Parallel strand lumber beam (PSL)
5--Laminated veneer lumber beam (LVL)
6--Truss I-Joist beam
7--Box or Plywood beam
8--Flitch beam (wood and steel)
9--Steel beams

4. Beam Type—Solid Lumber Beam

5. Beam Type—Built-up Dimensional Lumber Beam
Dimensional lumber (2x6, 2x8, 2x10, 2x12) nailed, screwed, and/or glued together
Vertical placement—
Large size placed vertical

6. Example: Beam and Joist Attached with joist hangers
Joist are attached to beams with metal joist hangers
What type of beam is shown?

7. Beam Type—Glued Laminated
Dimensional lumber placed horizontally and glued together

8. Beam Type—Parallel Strand (Parallam) Lumber Beam

9. Beam Type—Laminated Veneer Lumber Beam
Laminated Veneer Lumber (LVL)
Made of ultrasonically graded douglas fir veneers with exterior adhesives under heat and pressure
1 3/4” wide x (5 1/2 to 18”) depth

10. Beam Type—Truss I-Joist Beam
Laminated or Solid wood (top and bottom chords)
OSB or Plywood web

11. Beam Type—Box or Plywood Beam
12” or 16” structure with plywood skin
Designed by architect or engineer

12. Beam Type—Flitch Beam A sandwich of wood and steel
An architect/engineer designed beam

13. Beam Type—Steel Beams S shape (American Standard shape)
Often called an I-beam
W & M shapes
Wide flange design
C shape
Channel shape
S--
I Shape
W or M
Shape C-
Channel

14. Beam Type—Steel Beams Drawing Callouts:
Shape, Nominal height x Weight/foot
Example: W10x25
WEIGHT PER FOOT OF BEAM
NOMINAL HEIGHT
SHAPE

15. Reaction
Reaction is the portion of the load that is transferred to the bearing points of the beam
A simple beam reaction to a load would be at the end supports. Each end would support or be required to carry half the total load

16. Calculating the Reactions of a Beam
Total load on beam should equal reaction loads:
25 x 900 = 22500#
R1 = 15/2 x 900# = 6750#
R2 = 10/2 x 900# = 4500#
R3 = (15/2 + 10/2) x 900 =11250#
Reaction formula R = wl 2
W = uniform load l = length of span R2 R3 R1
W = 900 #/ linear foot
Span = 15’-0”
Span = 10’-0”

17. Simple Beam Design
Simple beam has a uniform load evenly distributed over the entire length of the beam and is supported at each end.
Uniform load = equal weight applied to each foot of beam.

18. Simple Beam Design Terminology Conditions of Design Joist/Rafter
Beam/Girder
Post/Column
Span
Tributary area
Conditions of
Design
Uniform load over length of beam
Beam supported at each end
Beam span
15’-0”
Tributary area of beam

19. Simple Beam Design Tributary area Total Load on Beam
16’ x 15’ = 240 sq ft
Total Load on Beam
240 x 50#/sq ft = 12,000#
Load at each supporting end
12,000/2 = 6000#
Tributary area of beam
15’-0”
Beam span

20. Table Design Considerations
Total lbs of load and span
Lbs of load per (lineal) foot
Deflection Allowances (Stiffness)
Floor = 1/360: Meaning an allowance of 1” deflection for every 360” span, structure is solid with little deflection
Roof = 1/240: Meaning an allowance of 1” deflection for every 240” span, structure springs or deflects more than floors

21. Determine the size of a Solid Wood Beam using Span Table
1)Determine the tributary area and calculate the total load (W) for the beam, LL = 50#, DL = 13#, therefore TL = 63# x 12 x 63 = 7560 TLD
Select beam size from table
12’-0”
10’-0”
BEAM
20’-0”

22. Solution = 4 x 14 Beam 7560 TLD w/ span of 12’ Roof Design Area 1/240
Floor Design Area 1/360
Solution = 4 x 14 Beam

23. Crawl Space Floor Joist, Beam/Post

24. Reading the Steel Table
Table values of load are given in kips
1 kip = 1000 lbs
Shape and nominal size across the top
Weight per foot is given below designation
Span is located along the left side of table

25. Example of Using Steel Table
30’-0”
18’-0”
BEAM
Calculate load: 18 x 30 x 60 = TLD = 32.4 KIPS
Selected Beam
S18 x 54.7

26. Glued-Laminated Beam Table
Design Data: Span 18’, Load per linear feet = 674#

27. Columns and Post

28. Reading Column Tables Determine the column load
Establish the height of column
Set the column size by height and load

29. Steel Column Table Conditions: Height = 4.5’, Load = 19.4 kips
Solution: 2 ½ Dia x 5.79 PIPE COLUMN

30. Wood Post Table Conditions: Height = 4 feet, Load = 23,000
Solution: 4x6 WOOD POST

31. Load Considerations First floor loads (DL + LL) = 50#/sq ft
First floor partitions (DL) = 10#/sq ft
Second floor loads (DL + LL) = 50#/sq ft
Second floor partitions (DL) = 10#/sq ft
If Truss design no loads on interior structure(DL)
If rafter/ceiling joist design (DL) = 20#/sq ft
Roof load regionally varies (LL) = 20-50#/sq ft

32. Beam Sizing and Post Spacing
Trial & Error Method
1--Locate tributary area
2--Determine various conditions placing post to shorten the beam span
3--Go to tables & choose beam
4--Smaller beams are less expensive and usually better

33. Handout on Structural Analysis #2
Before doing calculations sketch problem to visualize conditions
Calculate the tributary loads for beams and columns conditions
Use Handout charts and tables and select beams and columns for conditions