Deflection by integration of load equation

AI Thread Summary
The discussion centers on determining the deflection curve equation for a cantilever beam subjected to a sinusoidal load. The key focus is on the boundary conditions necessary for solving the problem, specifically noting that at the fixed end (x=0), both deflection and angle are zero, while at the free end (x=L), the shear force and moment are also zero. The user initially misunderstands the moment condition at the fixed end but corrects this by recognizing it should not be zero. The conversation emphasizes the importance of accurately applying boundary conditions to derive the correct deflection equation. Overall, the exchange highlights the nuances of solving beam deflection problems with varying support conditions.
Freyster98
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Homework Statement



Determine the equation for the deflection curve for the cantilever supported at A with a load given by: q=q0*sin(\pix/L).

Homework Equations





The Attempt at a Solution



I think this is pretty straightforward, but want to be sure. I did a similar problem with a simply supported beam with the same load equation, shown in the attached diagram. Am I safe to assume that the ONLY difference in this problem with a cantilever is the boundary conditions used to solve for C1, C2, etc?

The boundary conditions would be:
at x=0,y=0...and at x=0,moment=0.
right?
 

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Right, typically you say to yourself what is zero at the boundaries. For a simply supported beam, the deflections are zero; for a fixed-fixed beam, both deflections and angles are zero. In the case of a cantilevered beam, on the fixed end you have zero angle and zero deflection, but the million dollar question is what is zero at the free end?
 
minger said:
Right, typically you say to yourself what is zero at the boundaries. For a simply supported beam, the deflections are zero; for a fixed-fixed beam, both deflections and angles are zero. In the case of a cantilevered beam, on the fixed end you have zero angle and zero deflection, but the million dollar question is what is zero at the free end?

The moment, right?

Going back to my "attempt at a solution", I believe I screwed up. For the cantilever, at x=0, y=0...and at x=0, dy/dx=0. I had put that at x=0,moment=0, which is wrong. Also, I'm going to need to use: @x=L,shear force=0...and @x=L,moment=0.
 
Yup, you're right on track now. Good luck
 
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