Deflection of partially loaded cantilever beam with non-homogeneous EI

AI Thread Summary
The discussion focuses on calculating the deflection of a cantilever beam with a fixed end and a uniform load applied from a distance L to the free end. The beam has non-homogeneous properties, with varying modulus of elasticity (E) and moment of inertia (I) across two segments. The approach involves solving the differential equations for deflection in each segment, using the bending moment equations M1 and M2. Participants emphasize the importance of determining the reactions at the fixed end and calculating the internal moments for accurate deflection results. The conversation highlights the need for careful integration of boundary conditions to ensure continuity in slope and deflection across the beam.
elepolli
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TL;DR Summary: I have a cantilever beam with fixed end, known rectangular cross section and total length h. A uniform load is applied on the beam from a distance L from the fixed end, to the free end. The E modulus and inertia I are known, and they are two different constant values for 0<x<L and L<x<0.
I want to know the deflection w(h) of the beam at the free end.

This is my approach, what do you think?
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sideways beam 01.png
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Your image is loaded sideways.

For ## 0 < x_1 \leq L_1## you solve

$$ \frac{d^2y}{dx_1^2} = \frac{M_1(x_1)}{E_1I_1} $$

Then, for ## L_1 < x_2 \leq L_2## you can solve

$$ \frac{d^2y}{dx_2^2} = \frac{M_2(x_2)}{E_2I_2} $$

Where the constants of integration (slope, deflection) at ##x_2 = 0 ## come from the end condition of the first section.
 
erobz said:
Your image is loaded sideways.

For ## 0 < x_1 \leq L_1## you solve

$$ \frac{d^2y}{dx_1^2} = \frac{M_1(x_1)}{E_1I_1} $$

Then, for ## L_1 < x_2 \leq L_2## you can solve

$$ \frac{d^2y}{dx_2^2} = \frac{M_2(x_2)}{E_2I_2} $$

Where the constants of integration (slope, deflection) at ##x_2 = 0 ## come from the end condition of the first section.
How should I calculate $M_1$ and $M_2$?
 
elepolli said:
How should I calculate $M_1$ and $M_2$?
Find the reactions at point A( force and moment). Then you write the internal moment at the end of the section as function of x in the typical way(by inspection, or integrating the shear).
 
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