(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A steel (Young's modulus = 210x109N/mm2) propped cantilever beam (Figure 1) supports a uniformly

distributed load (UDL) of 20kN/m. The beam cross section is a 150mm x 75mm x 8mm rectangular

hollow section (RHS), i.e. 150mm deep, 75mm wide and has an 8mm wall thickness. The cross

section is oriented so that bending occurs about its major axis of bending.

Figure 1

a) Calculate the support reactions at A and B,

b) Plot the shear force diagram,

c) Plot the bending moment diagram (on the tension side) and indicate maximum bending moment

value,

d) Calculate the maximum bending stress and state where it occurs,

e) Calculate the deflection at the mid-point between A and B.

i'm working on part c and am a bit confused as to how the bending moment diagram works.

2. Relevant equations

just moment equations

3. The attempt at a solution

I have the shear stress diagram and part of the bending moment.

the reaction forces at A and B are 26 2/3 and 53 1/3.

the equations

for Vx and Mx are as follows

0<=x<=3

Vx = 26 2/3 -20x

mx = 26 2/3 x - 10x^{2}

3<=x<=4

Vx = 53 1/3 - 20x

Mx - 53 1/3 - 10x^{2}

but the peace i struggle with i'm getting the end peace of the beam to deflect by alot more then the middle part, so if you have any input it would be very much appreciated.

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Finding the bending moment

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