Built-Up Beams and Shear Flow

built-up beam

beam fabricated by joining two or more pieces of material

box beam	glu-lam beam (glued laminate)	plate girder

 

design steps

1. beam is designed as if it were a single unit
2. the connections (nails, screws, glue, welds, bolts, rivets, etc) are designed to ensure beam behaves as a single unit (i.e. connections must be designed to transmit the load transfer from one piece to the next)

 

shear flow, f or q

the horizontal shear force per unit distance along the longitudinal axis of the beam (in the diagram below, it is force F₃ per unit length)

 

areas used when calculating Q

see M9.9