2026 Volume 69 Issue 4 Pages 140-149
This paper deals with a simultaneous optimization problem of stacking sequence and drop-off placement for a ply drop-off laminate under uni-axial tensional load to maximize the resin pocket strength. As a practical reinforcement design condition, although the stacking sequence of the thin plate side is fixed, only the ply orientation angle ratio for the thick plate side is fixed. That is, the ply drop-off placement and the stacking sequence for the thick plate side should be determined. The strength index evaluated from von Mises stress at the resin pocket for the three-layer laminate is defined as the objective function. For the practical application, empirical stacking constraints such as the number of consecutive layers, the ply orientation angle difference between adjacent layers and so on are imposed for the balanced symmetric laminate consisting of 0°, ±45°, and 90° plies. As the optimization method, the genetic algorithm with gene repair strategy is proposed to satisfy the above constraints. The optimal design solution d tends to cut the 0° plies first, and ensure a uniform distribution of the strength index through layers. The validity of the optimization result is then verified by using the three-dimensional finite element analysis.
