Cantilever spreadsheet for dummies

  • Thread starter Thread starter Dingomack
  • Start date Start date
  • Tags Tags
    Cantilever
Click For Summary
SUMMARY

This discussion focuses on creating an Excel spreadsheet to calculate the deflection of a cantilever beam based on desired maximum camber (Cmax) and beam length (L). The user seeks to derive formulas for three key questions: calculating Cmax as a percentage of the chord length, determining the distance from the fixed end where Cmax occurs, and finding the required deflection for given values of Cmax and L. The consensus is that Cmax occurs at approximately 42.265% of L, provided the deflection at the free end does not exceed 10% of L.

PREREQUISITES
  • Understanding of cantilever beam mechanics
  • Familiarity with Excel for spreadsheet calculations
  • Knowledge of beam deflection formulas
  • Basic principles of aerodynamics related to aerofoil design
NEXT STEPS
  • Research "Cantilever beam deflection formulas" for various loading conditions
  • Learn how to implement "Excel functions for engineering calculations"
  • Study "Aerofoil design principles" to understand the relationship between camber and performance
  • Explore "Material properties and their impact on beam deflection" for different materials
USEFUL FOR

Engineers, students in mechanical or civil engineering, and anyone involved in structural analysis or aerofoil design will benefit from this discussion.

Dingomack
Messages
3
Reaction score
0
Any (ideal) beam of length L, bent with a deflection of δ will have the same parabolic curve.

If that underlying assumption is wrong I am in trouble...

(Lots of views on the other thread, but no posts...so I'll try and boil it down to its essence)

Imagine:
Cantilever beam of length L with a concentrated load at the free end producing a curve. Draw a chord on the curve and you have an aerofoil with a width that varies along it's length - narrow at the ends and fatter near the middle. Let's call the widest point the maximum camber (Cmax).

I need to produce an excel spreadsheet where I can input a desired Cmax and a beam length L and output the required deflection of the beam, all in millimeters.

To help me get there I think I need equations for the following:

Q1. Calculate Cmax as a percentage of the chord length,
Q2. At what distance from the fixed end of the beam does the Cmax occur? If my first assumtion is correct - this should be a constant.
Q3. For a given Cmax and beam length L what is the deflection required.

I am not ignoring specific E (modulus of elasticity). The beam that is used will be made of all sorts of different materials, but if my assumption holds, then it is irrelevant.

A background of why I want to do this can be found on the:
Making an aerofoil with a cantilever thread.

Thanks in advance
 
Last edited:
Engineering news on Phys.org
Dingomack said:
Any (ideal) [prismatic cantilever] beam of length L, bent with a deflection of delta, will have the same [strike]parabolic[/strike] [cubic] curve.
Dingomack: True, only if the type of applied loading is the same; i.e., in your case, only if there is a concentrated load (P) at the cantilever free end.

Dingomack said:
Q2. At what distance from the fixed end of the beam does the Cmax occur? If my first assumption is correct, this should be a constant.
My following answer applies if the cantilever deflection at the free end (y1max) does not exceed 10 % of the cantilever length (L). Cmax occurs at 42.265 % of L, measured from the fixed end; i.e., Cmax occurs at x = 0.42265*L.

If y1max exceeds 10 % of L, Cmax might still occur at 42.265 % of L, but I currently do not know if it does or not, because I have not checked that case.

Dingomack said:
Q3. For a given Cmax and beam length L, what is the deflection required?
What do you mean by "required"? Did you instead mean, "What is the deflection"? Which deflection? Deflection where, at what point?

Dingomack said:
I need to produce an excel spreadsheet where I can input a desired Cmax and a beam length L, and output the required deflection of the beam, all in millimeters.
What do you mean by "required deflection"?
 

Similar threads

Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 16 ·
Replies
16
Views
8K
Replies
9
Views
4K
Replies
33
Views
6K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
8K