Table of Contents

## What is BM and SF?

Shear Force (SF) and Bending Moment (BM) diagrams. Solution: A Cantilever of length l carries a concentrated load W at its free end. Draw the Shear Force (SF) and Bending Moment (BM) diagrams. Consider the forces to the left of a section at a distance x from the free end.

### What is shear and moment in beams?

Shear and bending moment diagrams are analytical tools used in conjunction with structural analysis to help perform structural design by determining the value of shear force and bending moment at a given point of a structural element such as a beam.

#### How will you sketch the moment diagram?

How to Draw Moment Diagrams

- The area of the first region in the shear diagram is . Draw a straight line from zero to -50ft*lb underneath the support at A.
- The area of region 2 of the shear graph is .
- The area of the triangular region 4 is , bringing the graph to 17.4 lbft.
- Region 5 is also a triangle.

**What is the formula for principle of moments?**

The Principle of Moments states that when a body is balanced, the total clockwise moment about a point equals the total anticlockwise moment about the same point. Moment =force F x perpendicular distance from the pivot d.

**What is the relationship between intensity of load SF and BM?**

To know the relation between Load, SF and BM, a small section CD of length Δ x \Delta x Δx is taken and FBD is drawn as below: The positive senses of SF and BM are shown and changes from V and M at face CC’ to V + Δ V V+\Delta V V+ΔV and M + Δ M M+\Delta M M+ΔM respectively at face DD’.

## How do we calculate the shear force and bending moment in the beams?

Calculating shear force and bending moment

- Step 1: Compute the reaction forces and moments.
- Step 2: Break beam into segments.
- Step 3: Compute shear forces and moments – first piece.
- Step 4: Compute shear forces and moments – second piece.
- Step 5: Compute shear forces and moments – third piece.