• Default: a rectangle pivoting at its corner. Customize with nodes + members.
• ⊕ Red pin = pivot C. — Amber string = arm r (C → force node, rotates with body). - - Purple = perpendicular distance d (true moment arm).
• Force arrow is fixed to the body and rotates with it. M = F · d (sign from r×F).
• Hit ”Show Rotation” to watch the body spin about C — the amber string sweeps like a clock hand.
• ⊕ Red pin = pivot C. — Amber string = arm r (C → force node, rotates with body). - - Purple = perpendicular distance d (true moment arm).
• Force arrow is fixed to the body and rotates with it. M = F · d (sign from r×F).
• Hit ”Show Rotation” to watch the body spin about C — the amber string sweeps like a clock hand.
Nodes
| # | x | y | Del |
|---|
Members
| # | i | j | Del |
|---|
Moment Center
Tip: In canvas, choose Set Moment Center and click anywhere.
Force (at Node)
(θ from +x, degrees)
String Method Output
d = perpendicular distance from center to line of action
d = perpendicular distance from center to line of action
—
F = (0, 0)
|F| = 0
d = 0
M = F·d = 0 kN·m
Sign: —
|F| = 0
d = 0
M = F·d = 0 kN·m
Sign: —
—
Notes:
- Moment sign uses M = (r×F)z where r = (P − C).
- Distance uses closest point from center to line of action.
- Rotation amplitude is scaled + clamped for readability.