Use a computer program to solve the truss design problems shown in Figures P3-64 through P3-72. Determine the single most critical cross-sectional area based on maximum allowable yield strength or buckling strength (based on either Euler's or Johnson's formula as relevant) using a factor of safety (FS) listed next to each truss. Recommend a common structural shape and size for each truss. List the largest three nodal displacements and their locations. Also include a plot of the deflected shape of the truss and a principal stress plot.

Figure P3-64 Derrick truss (FS 5 4.0)

Figure P3-65 Truss bridge (FS 5 3.0)

Figure P3-66 Tower (FS 5 2.5)

Figure P3-67 Boxcar lift (FS 5 3.0)

Figure P3-68 Howe scissors roof truss (FS 5 2.0)

Figure P3-69 Stadium roof truss (FS 5 3.0)

Transcribed Image Text:

F = 20 kip 25' 10' -10-- -25' 4000 Ib 16,000 IЬ 15' 3' 18-