Baltimore Subdivided Bridge Truss
16 m Baltimore truss with sub-panel nodes and 7 × 20 kN bottom-chord loads; demonstrates how sub-diagonals relieve outer top-chord panels and produce the characteristic force jump from −10 to −70 kN.
Category: truss · Difficulty: Expert
Solution
| Support | Rx (N) | Ry (N) | Mz (N·m) |
|---|---|---|---|
| L0 | 0 | 70000 | 0 |
| L4 | 0 | 70000 | 0 |
| Member | Axial force (N) | Sense |
|---|---|---|
| Member U0–U1 | -10000 | Compression |
| Member U1–U2 | -70000 | Compression |
| Member U2–U3 | -70000 | Compression |
| Member U3–U4 | -10000 | Compression |
| Member L0–s1 | 50000 | Tension |
| Member s1–L1 | 60000 | Tension |
| Member L1–s2 | 70000 | Tension |
| Member s2–L2 | 80000 | Tension |
| Member L2–s3 | 80000 | Tension |
| Member s3–L3 | 70000 | Tension |
| Member L3–s4 | 60000 | Tension |
| Member s4–L4 | 50000 | Tension |
| Member U0–L0 | -20000 | Compression |
| Member U1–L1 | 30000 | Tension |
| Member U2–L2 | 20000 | Tension |
| Member U3–L3 | 30000 | Tension |
| Member U4–L4 | -20000 | Compression |
| Member L0–U1 | -70711 | Compression |
| Member L1–U2 | -14142 | Compression |
| Member U2–L3 | -14142 | Compression |
| Member U3–L4 | -70711 | Compression |
| Member s1–U0 | 22361 | Tension |
| Member s2–U1 | 22361 | Tension |
| Member s3–U3 | 22361 | Tension |
| Member s4–U4 | 22361 | Tension |
All reaction values are computed by the StatIQ structural engine, not generated text. Signs follow the solver's convention: a positive Ry acts upward, a negative Ry downward; a positive M is counter-clockwise.