Engine vs formula: Relative difference 6.2 × 10−11 %
Sampled maximum axle effect: Engine 15 / Classical method 15 kN·m · 6.2 × 10−11 %
Open in Stabileo ↗Sparse Cholesky solver (96 free DOFs)
Residual 0.00e0 (96 free DOFs)
Closed form / Classical method
Statics for one span; force method for two spans: release the middle support and impose zero deflection there. Axle effect = axle load × influence ordinate.
Assumptions
Linear elastic, small displacements. Prismatic Euler–Bernoulli frame members; truss bars carry axial force only with ideal pin joints. Self-weight is excluded. No shear deformation, geometric nonlinearity or design checks.
Technical details
Production Stabileo solver · planar Euler–Bernoulli frame elements.
32 elements per span. Diagram extrema are sampled. Influence lines use 101 positions plus the section and its two sides; axle extrema are sampled, not an exact optimization. Shear is evaluated immediately left of the section.
Total nodal DOFs: 99