Robust buckling optimization of laminated composite structures using discrete material optimization considering “worst” shape imperfections

• Robust design optimization of laminated composite structures is performed.
• The optimization relies on a sequence of laminate and imperfection optimizations.
• A direct measure of the imperfection sensitivity is presented.
• Examples considered are a U-profile and a cylindrical panel.
• For both structures robust designs are obtained (decreased imperfection sensitivity).

Robust buckling optimal design of laminated composite structures is conducted in this work. Optimal designs are obtained by considering geometric imperfections in the optimization procedure. Discrete Material Optimization is applied to obtain optimal laminate designs. The optimal geometric imperfection is represented by the “worst” shape imperfection. The two optimization problems are combined through the recurrence optimization. Hereby the imperfection sensitivity of the considered structures can be studied. The recurrence optimization is demonstrated through a U-profile and a cylindrical panel example. The imperfection sensitivity of the optimized structure decreases during the recurrence optimization for both examples, hence robust buckling optimal structures are designed.