A simply supported beam ABC of length l carries a concentrated load P ...
Solution:
Given data:
Length of beam = l
Load on beam = P
Slope at point A = 0.75 times slope at point C
To find: Length of portion AN
Assumptions:
Beam is homogeneous and isotropic.
The deflection of the beam is negligible.
Beam is simply supported.
The beam is subjected to a concentrated load at point B.
The beam has negligible self-weight.
The bending moment at point B is zero.
Analysis:
Let us consider the beam ABC as shown in the figure below.
The beam is simply supported at points A and C.
The beam carries a concentrated load P at point B.
The bending moment at points A and C is zero.
Therefore, the bending moment at point B can be calculated as follows:
M_B = P * l / 2
The slope at point A is given as:
θ_A = 0.75 * θ_C
The slope of the beam at point A can be calculated as follows:
θ_A = M_B * l / (2 * EI)
where E is the modulus of elasticity of the beam material and I is the moment of inertia of the beam cross-section.
The slope of the beam at point C can be calculated as follows:
θ_C = M_B * l / (2 * EI)
Therefore, we have:
θ_A / θ_C = 0.75
(M_B * l / (2 * EI)) / (M_B * l / (2 * EI)) = 0.75
1 = 0.75
This is not possible.
Therefore, the given data is not consistent.
Hence, the length of portion AN cannot be determined.
Conclusion:
The given data is not consistent. Therefore, the length of portion AN cannot be determined.