SOLVER
✓ Direct Stiffness Method (DSM)
✓ 12-DOF 3D Euler-Bernoulli beam elements
✓ Linear elastic, small displacement (1st order)
− No shear deformation (Bernoulli, not Timoshenko)
− No geometric nonlinearity (no full P-δ)
− No imperfections (EN 1993-1-1 §5.3)
− No semi-rigid joints (all connections rigid)
− No member releases (all ends fully fixed)
P-Δ (SWAY)
✓ αcr computed per EN 1993-1-1 §5.2 Eq. 5.2
✓ Amplified sway method applied when 3 ≤ αcr < 10
− No iterative geometric nonlinear analysis (αcr < 3 not supported)
EC3 CHECKS (EN 1993-1-1)
✓ §6.2 Section resistance (Class 1/2/3 aware)
✓ §6.3.1 Flexural buckling y-y and z-z (curves a/b/c/d)
✓ §6.3.2 LTB with C1 moment gradient (NCCI SN003b)
✓ §6.3.3 Beam-column interaction (Annex B Method 2)
✓ Warping included in Mcr (Iw from section library)
✓ Effective length factor ky, kz per element
− No Section Class 4 (slender) — effective section not computed
− No biaxial bending check (§6.2.9 uses dominant axis only)
− No torsional-flexural buckling (§6.3.1 flexural only)
− No shear-moment interaction (§6.2.8) when V < 0.5 Vpl
LOADS & COMBINATIONS
✓ EN 1990 ULS (6.10), SLS Characteristic/Frequent/Quasi-permanent
✓ Global load projection for inclined members (correct for gravity on rafters)
✓ Notional horizontal forces §5.3.2 (φ = 1/200)
− No editable ψ factors or national annex selection
− No leading variable action logic (conservative envelope used)
For preliminary design and screening only. Results must be verified by a qualified engineer using full code-compliant software before use in construction documents.