# Introduction of Bending Moment, Equation, Calculation and Diagram

Bending moment is the reaction induced in a structural element when an external force or moment is applied to the element causing it to bend. The bending moment is calculated by multiplying the external force or moment by the distance from the force or moment to the point of interest. The point of interest is typically the point where the bending moment is being measured. The bending moment can be used to calculate theforces in the elements that make up the structure. The bending moment can also be used to calculate the deflection of the structure. The deflection is the amount that the structure bends under the load. The deflection can be calculated by dividing the bending moment by the stiffness of the structure. The stiffness of the structure is a measure of how much the

## What Is Definition of Bending Moment

- Bending moment is the force that produces bending or deformation in a structural member when an external force is applied
- This external force can be either static ( dead load ) or dynamic ( live load or wind )
- The deformation produced by the bending moment is usually measured in terms of the deflection of the member at some point.

## Types of Bending Moment

- There are three types of bending moments: cantilever, simple and fixed
- A cantilever is when there is a single beam protruding from a wall, with no support on the other end
- This creates a large amount of stress on the beam since it is holding up the entire weight of the structure
- A simple beam has two supports, one on each end, and is used to distribute weight evenly across the length of the beam
- A fixed beam is attached to a wall or other support and cannot move
- This type of beam is often used in trusses or roofs.

## What Do You Mean by Hogging Bending Moment

- When a beam is loaded in such a way that the resultant force acting on the beam is not perpendicular to the beam, the force produces a turning effect or moment on the beam
- The amount of the moment is proportional to the magnitude of the force and the distance between the force and the centroid of the beam’s cross section
- Theaspiring civil engineer must be well acquainted with the principles of statics and mechanics of materials in order to determine the magnitude and distribution of loads that act on structure, and to calculate the amount of bending moment that the structure must be able to resist.

## Sign Convention of Bending Moment

- There are three things to consider when looking at the sign convention for bending moments:
1

- The direction of the moment: is the moment acting to bending the beam in the clockwise direction or the counter-clockwise direction?

2 - The point of interest: is the point of interest on the beam above or below the neutral axis?

3 - The plane of interest: is the plane of interest the compression side or the tension side?
Using these three considerations, the sign convention for bending moments can be determined

- If the direction of the moment is clockwise, then the point of interest is above the neutral axis, and the plane of interest is the tension side
- Therefore, the bending moment is positive.
If the direction of the moment is counter-clockwise, then the point of interest is below the neutral axis, and the plane of interest is the compression side

- Therefore, the bending moment is negative.

## Conclusion

The bending moment is a very important concept in engineering, and it is important to understand how to calculate it and what factors influence it. The diagram is a very useful tool for understanding the concept. With a little practice, anyone can calculate the bending moment for a given structure and understand how it affects the strength of the structure.

## Frequently Asked Questions

### What is the importance of the bending moment in engineering?

The bending moment is a very important concept in engineering, as it is used to calculate the forces in the elements that make up the structure, as well as the deflection of the structure. Understanding how to calculate the bending moment, and what factors influence it, is essential for designing strong and stable structures.

### What are the three things to consider when looking at the sign convention for bending moments?

The three things to consider when looking at the sign convention for bending moments are the direction of the moment, the point of interest, and the plane of interest.

### What is the sign convention for bending moments?

The sign convention for bending moments is clockwise is positive, counter-clockwise is negative.