Calculating Re-acting Forces of 10m Beam w/ 3 Forces & Bending Moment Diagram

AI Thread Summary
The discussion revolves around calculating the re-acting forces and bending moments for a 10-meter beam subjected to three forces, including a distributed load. The user believes both re-acting forces are 40 kN each but is struggling with the calculations, particularly at the 10th meter where the bending moment does not equal zero as expected. Responses suggest verifying the signs in moment calculations and clarifying that the distributed load is a uniform load of 0.5 kN/m across the beam. The asymmetry of the applied loads is highlighted as a factor affecting the re-acting forces. Accurate calculations and a clear understanding of the load distribution are essential for resolving the issue.
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Question : A beam 10 meters long, with 3 forces acting on it and 2 re-acting forces on it to keep it in equilibrium. The re-acting forces are at 2 meters from either end. The forces onto the beam are at 3 meters from the left end of 10kN, 10 meters from the left end of 20KN and a distributed load over the full 10 meter beam of 5KN.

a) work out the 2 re-acting forces
b) Calculate the bending moment at 1meter intervals along the beam
c) Draw a bending moment diagram of the beam


Right so there's the question, my issue I believe; is calculating the re-acting forces, I have tried numerous ways, and believe that both reacting force will be 40KN each.

As taking moments from R1, (10 x 1) + (50 x 3) + (20 x 8) = R2 x 8
R2 = 40

As the UDL = 50KN at 5 meters, R1 = 80 - 40 =40KN

Then I drew a sheer diagram which seemed fine.

Then I calculated each meter individually expecting the 10th meter to equal zero.

However I get M10 = 0 - (10 x 5 x5) + (40 x 8 ) - (10 x 7 ) + (40 x 2) = 60
Obviously not right!

Could someone please give me some guidance whether you believe it's the re-acting forces or whether it's my calculations for working out each meter.

Any Help Would Be Appreciated.
 
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The applied loads are not symmetrical, so the reacting loads are not symmetrical.
Double check the signs of your moment calculations.
The way the problem statement is given, a load of 5kN is distributed oven the length of the beam. I read this as a UDL of 5 kN / 10 m = 0.5 kN / m
 
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