Optimum weight design of multilayered fiber composite plates with discrete ply angles and uncertainty in ply thicknesses
Jarosław Latalski
Quarterly No. 4, 2014 pages 183-188
DOI:
keywords: laminate plate, optimization, manufacturing tolerances, robust design, structural stability
abstract The presented paper discusses the minimum weight design of multilayered fiber composite plates with tolerances in individual ply thicknesses. These tolerances are given by the maximum acceptable deviation of every individual ply thickness from its nominal value. The robustness of the design is achieved by diminishing the design state variable (buckling load factor) by the product of arbitrary assumed tolerances and appropriate sensitivities. The proposed approach is illustrated with examples of a simply supported rectangular laminated plate design under uni- and bi-axial compression. The minimum weight identified by the total number of layers is found to assure plate stability. For the discussed analysis, buckling load sensitivity formulas with respect to ply thicknesses are given. Based on these relations, the impact of the discussed variations on the optimal laminate stacking sequence and buckling mode shape is studied in detail. The achieved results emphasize the importance of robust design opposed to merely nominal approaches.