Demonstrating the Shift from Rigidity to Tension

This simple mechanical demonstration beautifully illustrates a key structural idea: replacing rigid elements that resist bending with flexible members that work only in tension.

In the first part of the video, the rods are held together by rigid corner angles. These angles lock the joints, giving the structure bending stiffness — much like a conventional rigid frame or platform.

When the angles are removed and strings are added instead, the structure loses bending resistance but gains stability through tension. The load paths change completely: instead of relying on material rigidity, the geometry and the taut strings together stabilize the form. The rods now work purely in compression, while the strings carry tension — forming a balanced, lightweight structure.

The same principle underlies the modular pressure vessels and tendon-linked floating platforms developed here.
In those systems, the modules themselves carry compression internally through pressure, while external tendons carry tension, just as the rods and strings do in the demonstration.
Rather than building massive rigid floats to resist bending and compression, the architecture channels all forces into pure tension and internal pressure, achieving strength and stability with a fraction of the mass of conventional rigid platforms.