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 | 70 | 0 |
| L4 | 0 | 70 | 0 |
| Member | Axial force (N) | Sense |
|---|---|---|
| Member 15 | -10 | Compression |
| Member 16 | -70 | Compression |
| Member 17 | -70 | Compression |
| Member 18 | -10 | Compression |
| Member 19 | 50 | Tension |
| Member 20 | 60 | Tension |
| Member 21 | 70 | Tension |
| Member 22 | 80 | Tension |
| Member 23 | 80 | Tension |
| Member 24 | 70 | Tension |
| Member 25 | 60 | Tension |
| Member 26 | 50 | Tension |
| Member 27 | -20 | Compression |
| Member 28 | 30 | Tension |
| Member 29 | 20 | Tension |
| Member 30 | 30 | Tension |
| Member 31 | -20 | Compression |
| Member 32 | -70.711 | Compression |
| Member 33 | -14.142 | Compression |
| Member 34 | -14.142 | Compression |
| Member 35 | -70.711 | Compression |
| Member 36 | 22.361 | Tension |
| Member 37 | 22.361 | Tension |
| Member 38 | 22.361 | Tension |
| Member 39 | 22.361 | 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.