Purpose Numeracy

Basics

• OSE design = function, material use optimization, materials Degeneracy, structural calculations, materials selection, modularity, build speed, incremental design, economics (cost calculations) lifetime design.
• PSI of wood - 1000
• PSI of steel -50000
• PSI of plastic - 5000
• PSI of rock - 5000

Exercises in Structural Design With Wood

State your assumptions. The answer follows.

• Calculate pullout force of a nail in wood
• How deep would a nail have to be driven into wood to break before pulling out?
• Calculate pullout force of deck screw per inch.
• When you reinforce 2x4 lumber at a joint with a 2 foot piece, how many deck screws would you need to use at the joint so that breakage of wood happens before pullout of screws?