Shear Force Diagrams (SFD) and Bending Moment Diagrams (BMD) are the foundational tools that every structural and mechanical engineer reaches for when sizing a beam. Before you can pick a cross-section, choose reinforcement, or even argue about deflection, you need to know where along the beam the internal forces peak — and that's exactly what these diagrams reveal.

This lecture walks through a worked numerical example step-by-step, which is the right way to learn this topic. The general procedure is straightforward but unforgiving: resolve the supports using equilibrium, cut the beam at each load discontinuity, write the shear and moment as functions of position, and plot. The traps are in the sign conventions and the boundary conditions at point loads versus distributed loads — places where a careful instructor adds real value over a textbook.

What makes this worth picking over the other beam-analysis candidates: the competing videos either lean on proprietary software (ProtaStructure), sell a spreadsheet, or are 30-second shorts that skip the derivation entirely. A patient numerical walkthrough on a chalkboard or whiteboard, from a small channel focused on mechanics fundamentals, is the format that actually builds the skill. If you can hand-solve SFD/BMD for a beam with mixed point loads and a UDL, you understand the physics the software is doing for you.