Analyzing Cantilever Beam Bending: Is My Solution Accurate?

Click For Summary

Discussion Overview

The discussion revolves around the analysis of cantilever beam bending, specifically focusing on the accuracy of a participant's solution to a homework problem involving deflection and rotation in both the y and z directions. The scope includes mathematical reasoning and technical explanations related to beam mechanics.

Discussion Character

  • Homework-related
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant expresses uncertainty about the correctness of their solution for part (a) and invites others to verify it.
  • Another participant confirms the correctness of part (b) but suggests that the participant may need to compute the z-direction deflection and rotation in addition to the y-direction.
  • A correction is noted regarding a numerical error in the participant's work, specifically a miswritten value.
  • A participant introduces a formula for calculating total deflection as the resultant of deflections in the y and z directions, questioning how to find the resultant rotation.
  • There is a suggestion to state the y and z components of rotation separately rather than calculating a resultant rotation.
  • The original poster indicates they will leave their answer for rotation in terms of the y and z components.

Areas of Agreement / Disagreement

Participants generally agree on the correctness of certain parts of the solution, but there remains uncertainty regarding the need for z-direction calculations and the method for determining resultant rotation. The discussion does not reach a consensus on these points.

Contextual Notes

Some assumptions about the definitions of deflection and rotation in the context of beam mechanics may not be explicitly stated. There are unresolved questions regarding the calculation of resultant rotation.

Who May Find This Useful

Students and practitioners interested in structural engineering, mechanics of materials, or those working on similar homework problems related to beam analysis may find this discussion relevant.

temaire
Messages
275
Reaction score
0

Homework Statement



e42b7057-6171-49ad-84ae-f150edad9d4d.png


The Attempt at a Solution



5a85930c-7388-452c-bec6-6f658d3a488c.jpe


Is my work correct?
 
Physics news on Phys.org
temaire: I do not know if part (a) is correct, because I do not remember the formula. I will let someone else check part (a).

Your answer for part (b) currently looks correct. In part (c), you currently computed only the y-direction deflection and rotation, which are correct. But I think you now might also need to compute the z-direction deflection and rotation.

You accidentally typed 877, instead of 866, although you did not use it.

By the way, kN/m^2 is called kPa. Always use the correct, special name for a unit. E.g., 7214 kPa, not 7214 kN/m^2. However, it is better if you use 7.214 MPa, instead of 7214 kPa.
 
I've calculated the deflection and rotation of the beam in the z-direction.

I know that the total deflection of the beam is the resultant of the deflections in the y and z directions, as shown

\delta = \sqrt{u^2 + v^2}

where u is the deflection in the z-direction and v is the deflection in the y-direction.

However, how do I find the resultant rotation? Do I simply use the above formula and just switch u and v with the \theta_y and \theta_z?
 
temaire: Your resultant deflection looks great. Regarding the resultant rotation, we would need to think that over for awhile. I am not sure yet. However, would you settle for just stating the y and z components of rotation? You might not need to compute a resultant rotation. Just state the two components, theta_y and theta_z (?).
 
Yes, I am leaving my answer for rotation in terms of y and z.

Thanks for the replies.
 

Similar threads

Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 4 ·
Replies
4
Views
4K
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
3
Views
13K
  • · Replies 14 ·
Replies
14
Views
10K
Replies
2
Views
8K