Improved Genetic Algorithm with Two-Level Approximation Method for Laminate Stacking Sequence Optimization by Considering Engineering Requirements

Table 4

Practical optima of composite panels.

	Laminate; Ex: exterior part; In: interior part	Plies	Weight, kg (B/A)	Critical buckling factor (B/A)
Case	0/45/−45/0/−45/45/0/45/−45/0/−452s	(Ex)—24	0.8258/0.8258	0.76/0/76
	90/45/902s	(In)—08
Case	0/45/0/45/−45/0/−45/0/−45/0/−45/45s	(Ex)—24	0.8343/0.8258	0.73/0.72
	−45/90/−45/90s	(In)—08
Case	02/45/−45/0/45/−45/02/45/−45/0s	(Ex)—24	0.8258/0.8258	0.74/0.74
	90/45/−45/90s	(In)—08
Case	0/45/−45/0/45/−45/02/45/−45/0/45s	(Ex)—24	0.8774/0.8774	0.77/0.77
	−45/90/−45/45/90s	(In)—10
Case	0/−45/0/45/−45/0/45/−45/0/−45/0/−45s	(Ex)—24	0.8774/0.8774	0.78/0.78
	−45/45/90/−45/90s	(In)—10
Reference [26]	(−45/45)2/45/0/−45/05s	(Ex)—24	0.8258
	90/−45/45/90s	(In)—08

A: after rounding, B: before rounding; #: critical buckling factor in reference, and ##: value given by Nastran.