Model & diagrams
Support reactions
Summary
Values at a section
Sign convention — you type loads positive downward and moments positive
clockwise; a negative number flips them. In the diagrams, positive V
rotates the segment clockwise and positive M bends it concave upward (sagging),
with v positive upward. Inside, the solver uses x right, y up,
counter-clockwise, so dV/dx = q and dM/dx = V hold with
q positive upward. Analysis is Euler–Bernoulli (bending only, shear
deformation neglected), small displacements, linear elastic.