What is the maximum bending moment for this beam?

AI Thread Summary
The discussion centers on calculating the maximum bending moment for a beam with overhanging supports, a uniformly distributed load (UDL), and a point load. The user is confused about the calculations involving the UDL, particularly its application when it does not extend over the entire beam. Clarifications are provided regarding the correct units and the representation of the UDL as a concentrated load for determining support reactions. It is emphasized that the UDL can be treated as a single load acting at its center of gravity for analysis. Understanding these principles is crucial for accurately solving the problem.
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Homework Statement



Problem: For the beam according to the image, solve graphical and analytical:

1.) Reactions in the supports,
2.) Bending moment diagram,
3.) Maximum bending moment

Given variables:
F = 14 kN
q = 40 N/cm
a = 100 cm
b = 55 cm
l = 180 cm

TS2dfMZ.png

Homework Equations


This is a Beam with both overhanging supports, with a UDL and a point load on the right overhang. And I cannot find information for solving this.

Sorry for my terminology, I am doing physics in another language.

I am having a lot of trouble with the solving of this problem. What really confuses me is the UDL (I hope this is the correct terminology) that isn't over the entire beam, but hangs off on the left side.

I can't find any problems in my book that solve this kind of problem, and the professor didn't go into detail.

The Attempt at a Solution



This is a Beam with both overhanging supports, with a UDL and a point load on the right overhang.

My attempt at this was trying to figure out the force F_{q}, with: F_{q} = q*l => 40 * 280 = 11200 N/cm, 112 N/m, 0,112 kN/m

And assuming that the above is correct, which I do not know, I can go ahead and find F_{A} and F_{B}
 
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Antex said:
My attempt at this was trying to figure out the force F_{q}, with: F_{q} = q*l => 40 * 280 = 11200 N/cm, 112 N/m, 0,112 kN/m

And assuming that the above is correct, which I do not know, I can go ahead and find F_{A} and F_{B}
The numbers are right, but not the units. If you multiply N/cm by cm what do you get?
 
haruspex said:
The numbers are right, but not the units. If you multiply N/cm by cm what do you get?

Just N?
 
Antex said:
Just N?
Yes.
 
haruspex said:
Yes.

Could you explain me the difference if there was no overhang at A, and the UDL ended at A? Is there a different process in calculation in that case?

And also: 11200 N is then 112 kN? or would it be N/m and then 1.12 kN?
 
1. The difference is in the position where Fq "grabs". Otherwise same calculation.
2. No: 11200 N = 11200 N / (1000 N/kN)
or if you are word-oriented: eleven thousand 200 = eleven thousand plus (200 * thousand/thousand) = (eleven plus 200/thousand ) * thousand​
 
Antex said:
Could you explain me the difference if there was no overhang at A, and the UDL ended at A? Is there a different process in calculation in that case?

And also: 11200 N is then 112 kN? or would it be N/m and then 1.12 kN?
When determining the support reactions, the UDL can be represented by a single concentrated load of 11,200 N acting at the center of gravity of UDL, that is, at (a + l)/2 from the left end of the beam.
 
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