Deflection of L Shaped Cantilever Beam

In summary, the conversation discusses finding the horizontal and vertical deflection of point C in a diagram, as well as the angle of deflection for point C. The suggested solution involves using the equations δv = ML^2/2EI and ∅= ML/EI = PL^2/2EI, and replacing the moment with an equivalent point load acting at C. There is also a discussion about the transfer of torque and deflection in the L-shaped part. However, there are questions and doubts about the correctness of this solution and further guidance is requested.
  • #1
Wil_K
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Homework Statement


I would like to know how to find the horizontal and vertical deflection of point C shown in the attached diagram. I also need to find the angle of deflection for point C.


Homework Equations





The Attempt at a Solution


I've already found a solution to this problem, but I'm not sure if it's correct. I figured that the vertical deflection can be found by analysing the horizontal member using: δv = ML^2/2EI. Then I replaced the moment with an equivalent point load acting at C, which gives the same deflection. Then I found the moment acting about point B as a result of the equivalent point load, and used the above formula to find the horizontal deflection of the vertical member.

For the total angle of deflection I just added the deflection angles for each section, which were found using: ∅= ML/EI = PL^2/2EI.

I have doubts that this is the correct solution, so it would be great if someone could steer me in the right direction.
 

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  • #2
Wil_K said:
Then I replaced the moment with an equivalent point load acting at C
You cannot in general simply replace a torque with a force. It may exert the correct torque about some point, but not about all points, and it will exert a linear force which the torque did not.
A torque is applied to BC. For equilibrium of BC, AB must exert an equal and opposite torque, but no linear force, on BC. Similarly, the support at A must exert a pure torque on AB.
 
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  • #3
That applied torque M is transferred unchanged all the way until reaching the anchoring point A, where a reactive equal and opposite moment appears.
The deflection of each length of the L-shaped part depends on how long each one of those is.
 
  • #4
Lnewqban said:
The deflection of each length of the L-shaped part depends on how long each one of those is.
Not sure what you mean by that. The moment will bend AB, causing a displacement of B, and bend BC, causing a displacement of C relative to the displaced B.
 
  • #5
haruspex said:
Not sure what you mean by that. The moment will bend AB, causing a displacement of B, and bend BC, causing a displacement of C relative to the displaced B.
Yes, I was thinking of horizontal displacement of B (and C) and vertical displacement of C.
 

FAQ: Deflection of L Shaped Cantilever Beam

What is the definition of deflection in the context of L shaped cantilever beams?

Deflection refers to the amount of bending or displacement that a beam experiences when a load is applied to it. In the case of L shaped cantilever beams, the deflection is measured as the distance between the original position of the beam and its final position after the load is applied.

What factors affect the deflection of an L shaped cantilever beam?

The deflection of an L shaped cantilever beam is primarily affected by the magnitude and distribution of the applied load, the material properties of the beam (such as its Young's modulus and cross-sectional area), and the length and geometry of the beam.

How is the deflection of an L shaped cantilever beam calculated?

The deflection of an L shaped cantilever beam can be calculated using the Euler-Bernoulli beam theory, which takes into account the beam's dimensions, material properties, and applied load. This theory provides a formula for calculating the deflection at any point along the beam's length.

What are some common applications of L shaped cantilever beams?

L shaped cantilever beams are commonly used in various structures, such as bridges, buildings, and cranes, to support loads and resist bending. They are also used in mechanical and aerospace engineering for applications such as cantilevered wings and support structures for large machines.

How can the deflection of an L shaped cantilever beam be minimized?

The deflection of an L shaped cantilever beam can be minimized by selecting a material with a high Young's modulus, increasing the beam's cross-sectional area, and reducing the length of the beam. Additionally, proper design and reinforcement techniques can also help to minimize deflection and increase the beam's strength.

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