Pin Jointed Truss Analysis & Design

1) Truss and Tie Model ( Compression = Truss, Tension = Tie).

Truss / Strut = Compression

Tie = Tension

Statically Determinate structure must satisfy:

Pratt Truss



2j = m + 3

j = no. of joints
m = no. of members

For the Pratt Truss above no of joints = 10, no. of members = 17

2 (10) = 17 + 3

Therefore as expected the Pratt Truss is statically determinant.