A 2D truss solver built from scratch, using the same direct stiffness method (matrix structural analysis) used professionally: define a Warren truss's span, height, panel count and loads, and watch member tension/compression and the deflected shape update live.
⚙️ How it works: this is the direct stiffness method — the same matrix structural analysis used in real FEM solvers, just for a 2D pin-jointed truss instead of a full 3D mesh. Each member's local stiffness matrix (from its length, angle and EA) is assembled into a global stiffness matrix K; joint loads form the load vector F; solving K·u = F (Gaussian elimination, after removing the fixed support DOFs) gives every joint's displacement. Member axial forces then follow directly from each member's elongation. No numerical approximation of the physics — it's an exact linear-elastic solution for the geometry and loads shown.