List of Steel Beam Posts-part-3b.
Deflection of steel beams.
The post is part of a list of steel Beam posts-part-3b, including deflection disadvantages.
2-The permitted limits of deflection.
3- What are the Deflection limitations in the unified building code?
4- What is the C1 coefficient as a deflection parameter by the AISC?
![Pict -1-List of steel beam- part 3b The required deflection values as a ratio of the span length.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-1-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -1-List of steel beam- part 3b The required deflection values as a ratio of the span length.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-1-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -2-List of steel beam- part 3b C1 value used by the CM#15 for deflection equation.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-2-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -2-List of steel beam- part 3b C1 value used by the CM#15 for deflection equation.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-2-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is the link for post 24: Deflection of steel beams.
A solved problem 5.1 from Prof. Fredrick Roland’s book. Example 5.1-part 1.
The 30-foot beam is laterally supported for its entire length. It supports a uniform dead load, including a beam weight of 0.30 kip/ft and a uniform live load of 0.70 kip/ft. In the first part, we will find the required moment of inertia value Ix based on the Total load and Ix based on the LL.
![Pict -3-List of steel beam- part 3b Solved problem 5.1-estimate the ultimate moment.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-3-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -3-List of steel beam- part 3b Solved problem 5.1-estimate the ultimate moment.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-3-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -4-List of steel beam- part 3b. Find the requied Ix.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-4-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -4-List of steel beam- part 3b. Find the requied Ix.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-4-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is a link to post 24a– Easy approach to the solved problem-5-1-part 1-2.
A solved problem 5.1 from Prof. Fredrick Roland’s book- part 2.
In part 2, we will estimate the ultimate moment in the LRFD design. We will use Table 3-2 to select a W section and check the Ix for the chosen section against Ix values based on deflection. We will use Table 3-3 to select the proper section based on Ix. Check the section chosen for The ASD design.
![Pict -5-List of steel beam- part 3b. Use table 3-3 for Ux to select a W section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-5-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -5-List of steel beam- part 3b. Use table 3-3 for Ux to select a W section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-5-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is a link to post 24b– Easy approach to solved problem-5-1-part 2-2.
Part 1/4 Solved problem 9-9-6: how to find LL?
Part 1 includes a solved problem,9-9-6, from Prof. Charles G Salmon’s book. Determine the service live load the beam may carry if the Dead load is 0.15 kip/ft, including the beam weight. Use load and factor design. The steel has Fy=65ksi. The given beam is a built-up beam. We will use Table b4.1B to determine the limiting value for flange and web parameters for local buckling.
The first part of the solution includes determining the lambda coefficients λp-F λr-F, λp-w λr-w for Local buckling for the Flange and the web of the Built-up section.
Both the flange and web sections are Non-Compact sections since the limiting parameters are less than those of lambda Plastic.
![Pict -6-List of steel beam- part 3b. estimate of lambda plastic for flange,lambda r for flange.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-6-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -6-List of steel beam- part 3b. estimate of lambda plastic for flange,lambda r for flange.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-6-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is the link to post 25 –How to find LL- Part 1/4?
Part 2/4 for the Solved problem 9-9-6, how to find LL?
The second part of the solution includes determining the section modulus of elasticity for the Built-up section. Two nominal moment one is based on the limit state of local buckling for Flange and the other is based on the local buckling of the web section. After checking the lateral torsional buckling, the final decision on the final value of the nominal moment will be made, which will be included in the next two parts.
![Pict -7-List of steel beam- part 3b. The nominal moment for the Built-up section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-7-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -7-List of steel beam- part 3b. The nominal moment for the Built-up section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-7-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is the link to post 26- Part-2-4 of the Solved problem 9-9-6, How To Find LL?
Part 3/4 for the Solved problem 9-9-6, how to find LL?
The third part of the solution includes the lateral-torsional buckling parameters Lp and Lr for the built-up section, estimating the value of limiting length lr.
![Pict -8-List of steel beam- part 3a The value of Lr.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-8-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -8-List of steel beam- part 3a The value of Lr.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-8-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is the kink to post 27: Part 3/4 of the Solved problem 9-9-6, how to find LL?
Part 4/4 for the Solved problem 9-9-6, how to find LL?
The fourth part of the solution includes evaluating the nominal moment for the section based on the Lateral torsional buckling and then finalizing the LRFD value of the Final nominal moment to estimate the permitted Live load value.
![Pict -9-List of steel beam- part 3a The final live load for the Built-up section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-9-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
![Pict -9-List of steel beam- part 3a The final live load for the Built-up section.](https://b3049824.smushcdn.com/3049824/wp-content/uploads/2024/06/Pict-9-List-of-steel-beam-part-3b.jpg?lossy=2&strip=1&webp=1)
Here is the link to post 28: Part 4/4 Solved problem 9-9-6, how to find LL?
The next post will be the list of steel beam posts, part 4.
A very useful external resource A Beginner’s Guide to Structural Engineering