King-Post Roof Truss
Inverted king-post truss (tie-beam above, apex below) with a 120 N symmetric central load; the king post is a zero-force member by the collinear-joint rule, and rafters carry tension while the horizontal tie-beam carries compression.
Category: truss · Difficulty: Basic
Solution
| Support | Rx (N) | Ry (N) | Mz (N·m) |
|---|---|---|---|
| A | 0 | 60 | 0 |
| C | 0 | 60 | 0 |
| Member | Axial force (N) | Sense |
|---|---|---|
| Member 5 | -80 | Compression |
| Member 6 | -80 | Compression |
| Member 7 | 100 | Tension |
| Member 8 | 100 | Tension |
| Member 9 | 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.