Optimal design of composite wing structures with blended laminates

A framework for design and optimization of tapered composite structures. Part II: Enhanced design framework with a global blending model

“…According to Table 1, if a panel consists of shared layers with big areas, its panel continuity ratio is big (e.g. panels 4,5,6,8,9); otherwise, the panel continuity ratio is small (e.g. panels 1, 2, 3, 7).…”

“…a wing box [3,6,7], blade stiffened composite panels [5,15], an 18-panel horseshoe [8][9][10][11][12][23][24][25][26][27], a wing skin structure [19,20], a sailing boat [28], a vertical tail [29], a horizontal stabilizer of F-16A/B [30], an aircraft fuselage [32], etc. Various heuristic algorithms were adopted to deal with this problem, such as an improving hit-and-run (IHR) algorithm [2], a genetic algorithm (GA) [3][4][5][6][7][8][9][10][11][12]24,25,27,30,31], an ant-colony optimisation (ACO) [14], an evolutionary algorithm (EA) [26,28,29], etc. Specific computational techniques were developed for stacking-sequence design, especially focusing on the blending issue: various parameterization techniques [13,15,28,29], a backtracking method [16]…”

Bilevel Optimization of Blended Composite Wing Panels

“…To improve structural integrity and avoid stress concentration between two adjacent panels, ply blending should be ensured. Although such requirements have been considered in [17][18][19][20][21][22][23][24], a problem of optimization of multipanel aircraft structures with a comprehensive consideration of buckling, strain, manufacturing constraints as well as general composite design rules including ply blending still remains to be addressed to the satisfaction of aircraft industry.…”

“…Later, the blending requirement has been considered in [18][19][20][21][22][23]. The composition continuity and the stacking-sequence continuity measures were defined in [18] and applied in an optimization process, also in [24].…”

“…This approach kept the total thickness of each panel obtained in the first (global) optimization step (with a margin of two to four plies) but redefined the stack composition for the sublaminates in the second (local) optimization step. Later, two blending methods, inward and outward blending, were developed in [20] to improve the ply continuity between adjacent panels using a guide based GA. An attempt to obtain global ply continuity using a stacking-sequence table (tabular method) was made in [22]. A sublaminate was repeatedly used as a stacking template for local level (laminate level) panel design, whereas laminate percentages were specified as 50% for plies of 0 deg, 40% for 45 deg, and 10% for 90 deg in the top-level (panel level) optimization.…”