131 Structural Forms

There are three structural strategies for creating things: mass, frames, and shells.

• Mass structures consist of materials that are piled or stacked to create solid forms. Their strength is a function of the weight and hardness of the materials. Consider mass structures for barriers and small shelters, especially when building materials are limited.

• Frame structures consist of struts joined to form a skeleton. Their strength is a function of the strength of the elements and joints, and their organization. Consider frames for large structures.

• Shell structures consist of materials that wrap around to contain a volume. They maintain their form and support loads without a frame or solid mass inside. Their strength is a function of their ability to distribute loads throughout the structure. Consider shell structures for containers, small cast structures, shelters, and designs requiring large spans.

See Also Factor of Safety • Modularity • Scaling Fallacy

Frames work well for large structures. Shells work well for lightweight shelters. Mass forms work well for simple barriers.