1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Bending of cantilever beam

  1. Nov 11, 2011 #1
    1. The problem statement, all variables and given/known data


    3. The attempt at a solution


    Is my work correct?
  2. jcsd
  3. Nov 11, 2011 #2


    User Avatar
    Science Advisor
    Homework Helper

    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.
  4. Nov 11, 2011 #3
    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

    [tex]\delta = \sqrt{u^2 + v^2}[/tex]

    where [itex]u[/itex] is the deflection in the z-direction and [itex]v[/itex] 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 [itex]u[/itex] and [itex]v[/itex] with the [itex]\theta_y[/itex] and [itex]\theta_z[/itex]?
  5. Nov 11, 2011 #4


    User Avatar
    Science Advisor
    Homework Helper

    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 (?).
  6. Nov 11, 2011 #5
    Yes, I am leaving my answer for rotation in terms of y and z.

    Thanks for the replies.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook