Beam Shear & Moment

For a simply supported beam with a point load, compute reactions, max shear, moment at load and at mid-span for SFD/BMD.

Inputs

Formula

RA = P(L−a)/L; Vmax = RA; Mload = P a b/L; Mmid = RA·L/2 − P·max(0,a−L/2)
P弯矩图 BMD
Beam Shear & Moment schematic

How to use

  1. Fill in Span L, Point load P, Load pos. a in the Inputs section (watch the unit on each field).
  2. Click Calculate; the tool evaluates the formula shown above.
  3. Read Reaction RA, Reaction RB, Max shear Vmax, Moment at load, Mid-span moment in the results area.
Formula notesShear V(x) = ∫load, bending moment M(x) = ∫V dx; M = 0 at simple supports.