### SHEAR FORCE AND BENDING MOMENT

Definition: Shear force: The force which tend to shear off the section and is obtained as the algebraic sum of all forces including the reactions acting normal to the axis of the beam either to the left or right of the beam. Sign convention Positive Shear Force Negative Shear Force Sign convention for shear force in brief Direction Positive SF Negative SF Left side Upward force Downward force Right side Downward force Upward force Bending moment: The algebraic sum of all the moments of the forces and reactions in a beam towards either left side or right side of the support is known as bending moment. Types of bending moment: Sagging bending moment: The moment about the point which produces convexity below the centre line is called as sagging bending moment. It is also called as positive bending moment. Consider the simply supported beam with central concentrated load “F”. The moment due to the force