#### Bending Moment and Shear Force diagrams

#### What is Bending Moment?

The element bends when a moment is applied to it. Every structural element has bending moment. Concept of bending moment is very important in the field of engineering especially Civil engineering and Mechanical Engineering.

Unit of measurement: Newton-metres (N-m) or pound-foot or foot-pound (ft.lb)

Bending moment is directly proportional to tensile and compressive stresses. Increase in tensile and compressive stresses results in the increase in the bending moment. These stresses also depend on the second moment of area of the cross section of the element.

#### What is Shear stress?

Shear stress is defined as the measure of force per unit area. Shear stress occurs in shear plane. There are many planes possible at any point in a structure which can be defined to measure stress.

Stress = Force/Unit area

#### Example: Bending Moment and Shear Force Calculations

**Simply supported bending moment**

M_{ab} = wl^{2}/8 = (22×4.14×4.14)/8

= 47.13 KN-m

M_{bc} = wl^{2}/8 = (22×4.14×4.14)/8

= 47.13 KN-m

**Fixed Moments**

**Moment about B**

wl^{2}/12 = (22×4.14×4.14)/12

= 31.4 KN-m

**Support reactions**

R_{A}+R_{B}+R_{C} = 2(22×4.14)

= 182.16 KN

3R_{A} = 182.16

R_{A} = 60.72KN

R_{A} = R_{B} = R_{C} = 60.72 KN

Also check out: **Introduction to Load Calculations**

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hw did we get the 30.36kn for the shear force diagram

me a diploma engineer, interested in structural designing, It will be very helpful if you post a complete structural analysis and design of any G+2 framed structure including load calculation, bending moment, etc. thank you in advance

Please, I need assistance in the use of Moment distribution method for designing beams, slabs,etc. I don’t have a firm grip of the basics, kindly open my eyes to the nitty gritty… tnx