Statics: Bending of a beam/evenly distributed force problem

Click For Summary
SUMMARY

The discussion focuses on calculating the largest bending stress, σb, in a beam subjected to an evenly distributed force (q). The specific equation used for bending moment at incision 2 is Mb = FA*aA - q*2.5m*1.25. The term 1.25 is clarified as a factor related to the geometry of the beam and the distribution of forces. Participants emphasize the need to define symbols such as aA and Mb, and suggest starting with the bending moment equations for sections 16.2 and 16.3, using x as the horizontal axis.

PREREQUISITES
  • Understanding of basic statics principles
  • Familiarity with bending moment calculations
  • Knowledge of beam theory and stress analysis
  • Ability to interpret engineering diagrams and symbols
NEXT STEPS
  • Study the derivation of bending moment equations in beam theory
  • Learn about the significance of factors in bending moment calculations
  • Explore the relationship between distributed loads and bending stress
  • Review examples of calculating reactions at supports in beams
USEFUL FOR

Engineering students, structural engineers, and professionals involved in mechanical design and analysis of beams under load.

hattori_hanzo
Messages
8
Reaction score
0
Hello, and sorry for my English, as I am Norwegian.

I have a statics problem which I can not understand.

I've taken a pic from my book:
eFcrt.jpg


The problem asks me to find the largest bending stress, σb, in the incisions 1 and 2.

I have the solution in front of me, I just don't understand what they have done with the evenly distributed force (q). Especially in incision 2, when they find Mb, they have used: Mb = FA*aA-q*2.5m*1.25.

The q*2.5m I can understand, but where does the 1.25 come from? I thought it should be divided by 2?

Can someone explain how this works for me?
 
Physics news on Phys.org
Especially in incision 2, when they find Mb, they have used: Mb = FA*aA-q*2.5m*1.25.

Please confirm what the symbols stand for.

In particular what is aA and Mb ?

You have not provided symbols for the reactions at A and B?
Do you know how to calculate these reactions?

You should start by writing the equation for the bending moments for 16.2 and 16.3, using x for the horizontal axis and starting with x=0 at A. Can you do this?
It will have the form M = some function of x and the loads to the left of x.
 

Similar threads

Undergrad Shear force and bending moments graph
  • · Replies 25 ·
Replies
25
Views
3K
Undergrad Rolling Without Slipping
  • · Replies 59 ·
2
Replies
59
Views
5K
Undergrad Statics: When the reactions depend on the displacements
  • · Replies 35 ·
2
Replies
35
Views
5K
Undergrad How is static friction the centripetal force during a car turning?
  • · Replies 73 ·
3
Replies
73
Views
11K
Undergrad Torque required from powered roller to rotate cylinder
  • · Replies 19 ·
Replies
19
Views
3K
Undergrad Base Motion and Vertical Beam - Basic Reaction Forces?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad Pressurized containers: Stress distribution and large displacements
  • · Replies 69 ·
3
Replies
69
Views
5K
Engineering Cantilever and encastré beams: bending moment and shear force
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Finding the Axis of Rotation with Given CoG and Force Point
  • · Replies 32 ·
2
Replies
32
Views
3K
Undergrad Drag Coefficient of a 'flexible' object (e.g. a piece of paper)
  • · Replies 4 ·
Replies
4
Views
2K