Shear & Bending Moment Diagram
Standard-case tables cover the beam in the textbook. This covers the one on your drawing: any number of point loads, distributed runs and applied moments, with the supports anywhere you like. Move a support inside the span to create an overhang — and watch the far reaction go negative, which is uplift, not a sign error.
Loads
| Type | x or start (mm) | end (mm) | Magnitude |
|---|
Point loads in N (positive = downward). Distributed loads in N/mm over the range given. Applied moments in N·mm (positive = clockwise). Loads outside the beam are ignored.
Shear force V(x)
Positive shear means the left-hand segment pushes up. Each point load is a vertical jump; a distributed load is a slope.
Bending moment M(x)
Positive is sagging — tension on the bottom fibre. The moment peaks where the shear crosses zero; if it does not on your diagram, something is wrong with the input.
Elastic, small-deflection, prismatic beam theory. Does not check lateral-torsional buckling, web crippling, shear stress or deflection — see Beam Calculator for deflection of standard cases and Steel Beam Check for a code-style capacity check. A helper, not a substitute for engineering judgment.