10 Principles for Manipulating
Structural Form

Jonathan Ochshorn
Chaing Mai workshop photos | homepage
1 Understand ideal "funicular" shape for assumed loads. Other images
2 Invert funicular form to switch between tension and compression. Other images
3 Switch between tension and compression by moving force along "line of action."
4 Allow moment diagram to influence overall structural form. Other images
5 Understand position of inflection points and their relation to internal hinges. Other images
6 Adjust cross-sectional shape based on deviation of actual from "ideal" overall form; or based on deviation of actual from "ideal" loads. Other images
7 Resolve bending moment into axial tension and compression. Other images
8 Balance thrusts through repetition and symmetry. Other images
9 Use triangulation or rigid joints to make structures stable under all possible loads. Other images
a. Triangle can resist load applied in any direction by resolving the load (force) into components corresponding to the legs of the triangle.
b. Legs of the triangle are in tension or compression, depending on the direction of the reaction to the load (force).
c. Compression members can be avoided by using cross-bracing, or by providing single braces in opposite directions.
10 Apply rules, especially for stability, to the third dimension. Other images
Copyright 2001 J. Ochshorn. First posted 28 July 2001; last revised 21 March 2003. return to homepage