All joints are pins (can rotate freely); all members have circular cross-sectional area, and are made of steel (E=200 GPa, v=0.3 and p=7860 kg/m3).

Optimization problem:

• Minimize the total mass of truss strucuture
• Subject to:    maximum axial stress <=150 MPa
                      maximum vertical displacement <= 0.05 m

• by varying cross-sectional area of the twelve members