Solid Mechanics Beam Stress Question

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Leighanne
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Homework Statement
Looking for some help in solving this practice problem, I have tried multiple times and can't seem to get to the correct answers.
Relevant Equations
The solid 30 mm diameter steel [E = 200 GPa] shaft shown in Figure supports two pulleys. For the loading shown, use discontinuity functions to compute:

(a) the deflection of the shaft at pulley B.

(b) the deflection of the shaft at pulley C.

answers: (1.539mm, 6.15mm)
Diagram of a shaft fixed to a wall at A, with pulleys at B and C; 800 N points down at B, 500 N points down at C, 250 mm from A to B and 350 mm from B to C.
Handwritten beam analysis: moment equilibrium and vertical force equations solving for reaction FBY = 2000 N, with a shear force diagram and bending moment diagram below a simply supported beam with loads at A, C and E.
 
Attachments
  • Diagram of a shaft fixed to a wall at A, with pulleys at B and C; downward forces of 800 N at B and 500 N at C, with 250 mm from A to B and 350 mm from B to C.
    Screenshot 2024-01-07 114117.png
    14.3 KB · Views: 145
  • Handwritten beam analysis: a beam with supports at B and D, loads 1000 N at A, 3200 N at C and 800 N at E, with shear force and bending moment diagrams below, plus moment equations and a shear stress formula tau = VQ/It.
    1704649548546.png
    35.6 KB · Views: 162
You are supposed to use the singularity function to find the deflections. You need to write the moment as a function of ##x##. Then the deflections come from integrating twice:

$$EI \frac{d^2y}{dx^2} = M(x)$$

Why are you trying to find the shear stress?
 
Uploaded the wrong solution attempt whoops!
heres the correct one.
Handwritten solution to a shaft deflection problem: moment equation M(x) = 1300x - 800<x-250>, integrated twice for EIθ and EIv with constants C1 = C2 = 0, then deflection at B, v = 3385416667 / (200x10^9)(89760.78) = 8.51 mm.
 
Leighanne said:
Uploaded the wrong solution attempt whoops!
heres the correct one.
View attachment 338230
There should be a constant moment that you have not included in ##M(x)##. There may be more, but start there( i.e there is vertical reaction and moment at A under equilibrium).