 Welcome back MechanicalEI. Did you know that unlike normal forces and moments which occur on the outside, shear force and bending moment occur on the inside of a beam? This makes us wonder, what is shear force and bending moment? Before we jump in, check out the previous part of this series to learn about what volumetric strain is. First, its graspy concept of an axial force which acts along the centroidal axis of the member. If the axial force acts through the centroid of a member, it is called concentric loading. If the force is not acting through the centroid, it is called eccentric loading. Shearing forces are unaligned forces pushing one part of a body in one specific direction and another part of the body in the opposite direction. When the forces are aligned into each other, they are called compression forces. An example is a deck of cards being pushed one way on the top and the other at the bottom, causing the cards to slide. A bending moment is the reaction induced in a structural element when an external force or moment is applied to the element, causing the element to bend. The most common or simplest structural element subjected to bending moments is the beam. For equilibrium, the moment created by the external forces and external moments must be balanced by the couple induced by the internal loads. The resultant internal couple is called bending moment. Hence, we first saw what axial forces and then saw what shear forces and finally went on to see what bending moment is.