Home / Structural Analysis / 2D Frame Solver A · v1.0

2D Frame Stiffness Solver

General direct-stiffness-method solver for 2D frames: define nodes, elements (E/A/I), loads, and supports; get displacements, reactions, and member end forces. Not tied to any specific code — pure structural mechanics.

Preset / Load Case

Nodes

IDx (mm)y (mm)Support (ux/uy/rz)

Elements & Loads

Node I → JE (MPa)A (mm²)I (mm⁴)
Point Load
At NodeFx (N)Fy (N)Mz (N·mm)

Results

This solver was cross-checked against three independently-derived reference cases (two by the unit-load/virtual-work method, one by the textbook cantilever formula δ=PL³/3EI) — all matched to within numerical solver precision (<0.001mm). See tests/frame-solver.test.js.

Citations

MethodDirect Stiffness Method — standard 2D frame element (combined axial + Euler-Bernoulli bending), global assembly via node/DOF mapping, boundary conditions applied by direct partitioning, solved by Gaussian elimination with partial pivoting.
Scope noteThis implementation targets small-to-medium frames (tens of nodes) typical of pre-design/educational use. Bandwidth-reduction (RCM) and banded Cholesky factorization — techniques that matter at thousands of DOF — were deliberately NOT added, since they add real complexity without measurable benefit at this problem scale.

Engine: engine/frame-solver.js · General mechanics (confidence A) ·

İndirilen betik bu modeli OpenSees'te yeniden kurar ve bu sayfanın bulduğu mesnet tepkilerini gömülü olarak taşır: python dosya.py ile çalıştırdığınızda iki bağımsız çözücünün sonuçlarını sapma yüzdesiyle yan yana basar. Birimler N ve mm’dir; betikte hiçbir dönüşüm yapılmaz.