Zero-Force Members — Isolated-Node Rule
Five-member truss where two members meeting at an isolated unloaded joint D are both zero-force (isolated-node rule); the active load path runs through the triangle only, demonstrating that structural dead-wood carries no force.
Category: truss · Difficulty: Intermediate
Solution
| Support | Rx (N) | Ry (N) | Mz (N·m) |
|---|---|---|---|
| A | 0 | 50 | 0 |
| B | 0 | 50 | 0 |
| Member | Axial force (N) | Sense |
|---|---|---|
| Member A–B | 50 | Tension |
| Member B–C | -70.711 | Compression |
| Member C–A | -70.711 | Compression |
| Member A–D | 0 | — |
| Member C–D | 0 | — |
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.