- #1
denk209
- 2
- 0
- Homework Statement
- I need to find everything I can about the beam but I dont know how to do the bending moment.
- Relevant Equations
- Σ M=0
Do Axial Forces Affect Bending Moments in Beam Calculations?
- Engineering
- Thread starter denk209
- Start date
In summary, when calculating moments around a point, it is important to consider all forces and applied moments, not just the ones to the left of the point. It is helpful to draw the moment diagram first and to remember that positive bending moments are clockwise per engineering convention. Additionally, the area under the shear diagram represents the change in moment between two points, and the slope of the tangent to the bending moment diagram at a chosen point is the shear at that point. Furthermore, when calculating moments at a specific point, it is important to ensure that the reactions at supports are correct and to double-check any simple math calculations.
- #2
denk209
- 2
- 0
I tried to get individual moments around point but let say for Mc I get = - Fay*4 + 320*2
so -622.44 for moment in point C
so -622.44 for moment in point C
- #3
PhanthomJay
Science Advisor
Homework Helper
Gold Member
- 7,201
- 529
Axial (normal) forces passing thru the point about which you are summing moments do not produce bending moments. It is confusing when you show these forces as pointing up and down on the beam.
In taking the moments about C , you need to consider all the forces and applied moments, not just the ones to the left of C.
It is best to draw the moment diagram first as best you can without too many values at first. Also, always treat positive bending moments as clockwise per engineering convention. Remember that the area under the shear diagram between 2 points represents the change in moment between those points. And The slope of the bending moment diagram tangent To the curve at a chosen point is the shear at that point.
Edit: o sorry I wasn’t thinking correctly your method for moment at C is correct. But your Answer is wrong because you need to correct your reactions at supports and watch your simple math.
In taking the moments about C , you need to consider all the forces and applied moments, not just the ones to the left of C.
It is best to draw the moment diagram first as best you can without too many values at first. Also, always treat positive bending moments as clockwise per engineering convention. Remember that the area under the shear diagram between 2 points represents the change in moment between those points. And The slope of the bending moment diagram tangent To the curve at a chosen point is the shear at that point.
Edit: o sorry I wasn’t thinking correctly your method for moment at C is correct. But your Answer is wrong because you need to correct your reactions at supports and watch your simple math.
Last edited:
1. What is a bending moment?
A bending moment is a measure of the amount of bending or stress that a material experiences when it is subjected to a load or force. It is typically measured in newton-meters (Nm) or pound-feet (lb-ft).
2. How is bending moment calculated?
Bending moment is calculated by multiplying the applied force by the distance between the force and the point of interest, also known as the moment arm. The bending moment can also be calculated by integrating the internal shear force along the length of the beam.
3. What is the difference between positive and negative bending moments?
A positive bending moment causes a material to bend in a concave upward shape, while a negative bending moment causes a material to bend in a concave downward shape. Positive bending moments occur when the top of a beam is in compression and the bottom is in tension, while negative bending moments occur when the top of a beam is in tension and the bottom is in compression.
4. How does beam shape affect bending moment?
The shape of a beam can greatly affect the bending moment it experiences. A beam with a larger cross-sectional area will be able to withstand greater bending moments, while a beam with a smaller cross-sectional area will experience higher bending moments and may fail under heavy loads. Additionally, beams with different shapes, such as I-beams or T-beams, will distribute bending moments differently.
5. Why is it important to consider bending moment in structural design?
Bending moment is an important factor to consider in structural design because it can determine the strength and stability of a structure. If a material experiences a bending moment that exceeds its capacity, it can lead to failure or collapse. Additionally, understanding the bending moment can help engineers design structures that can withstand expected loads and prevent potential disasters.
Similar threads
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
Engineering
Combined loading, where is the neutral axis?
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Engineering and Comp Sci Homework Help
-
Mechanical Engineering