History
1930s
- proportional limit strength tests → empirical formulas
- Forest Products Laboratory
- Wood Handbook
1940s
- yielding of various elements in the connection
- Europe
1980s
- engineering mechanics → yield limit theory for dowel-type fasteners
- only for shear loading
- withdrawal loading still covered by empirical formulas
source
Yield Limit = smallest value for a connection's various yield modes
Yield Mechanism = mode with smallest value
Advantages / Disadvantages
mathematically analyze any configuration
- different fastener materials
- mixed wood species
- wood + steel, etc.
lengthy equations
NDS
equations tables for common connections NDS equations already include ASD factors of safety.
Wood Handbook has separate equations for wood screws.
