How to Calculate Slope and Deflection for a Cantilever Beam with Mixed Loadings?

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SUMMARY

This discussion focuses on calculating the slope and deflection of a cantilever beam subjected to mixed loadings, specifically a uniformly distributed load (UDL) of 25N/m and a point load of 250N at the free end. The double integration method is mentioned as a previous approach, while the principle of superposition is emphasized as the key to solving the problem. The discussion references the book "Strength of Materials" by J. P. Den Hartog, which provides essential formulas for calculating rotations and deflections for various loading conditions.

PREREQUISITES
  • Understanding of cantilever beam mechanics
  • Familiarity with the double integration method for beam deflection
  • Knowledge of superposition principle in structural analysis
  • Basic concepts of bending moment and shear force
NEXT STEPS
  • Study the superposition principle for mixed loading scenarios in beam analysis
  • Learn how to apply the double integration method for cantilever beams
  • Review the relevant formulas for slope and deflection from "Strength of Materials" by J. P. Den Hartog
  • Explore additional resources on calculating deflections for different loading conditions
USEFUL FOR

Structural engineers, civil engineering students, and professionals involved in beam analysis and design will benefit from this discussion.

gk1989
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I have calculated one of the 2 questions successfully with it being a simply supported beam, now i am stuck on the remaining question. Previously i have used the double integration method.

It is as follows:

"A cantilever beam, 15m long has a UDL of 25N/m acting along its entire length and a point load of 250N at the free end. If EI for the beam = 100MN/m^2 calculate the slope and deflection of the beam at the free end "

How do i include 2 different load values which are of a different format UDL & point load? and how should the answer be carried out?
 
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Generally, superposition is the key. I have not looked at at mechanics in awhile, but I recall this being the trick.

Find the solution to one of the loadings, then find the solution due to the other loading, then sum the two solutions.

Whether you should use integration or tabulated formulas I don't know.

That depends on what your prof wants.
 
There is a book called Strength of Materials by J. P. Den Hartog (Dover edition) that contains a table/page for rotations and deflections of a cantilever beam subject to different loadings. I do not have my book handy with me, but the formulas are so straight-forward that they can be memorized by anyone vaguely familiar with the subject:

Loading rotation deflection
moment ML/EI ML^2/2EI
Point load at end PL^2/2EI PL^3/3EI
UDL wL^3/6EI wL4/8EI

The rotations and deflections refer, of course, to the free end of the cantilever.

You can get a description of the book at :
https://www.amazon.com/dp/0486607550/?tag=pfamazon01-20
 
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