Requirements for lower emissions and operating costs make mass reduction of composite structures a significant issue for future aircraft. Here, minimisation of normalised elastic energy under an uncertain, general in-plane loading is used to indicate laminate efficiency and by equivalence minimum mass. Results are the first to investigate the comparative robustness of standard and non-standard angles to uncertain loading. They indicate that weight reductions of up to 8% can be achieved if optimum design, using standard angle (θ = 0°, ±45° or 90°) and industrial design rules, is replaced by optimising non-standard angles (0° ≤ θ ≤ 180°) directly for uncertain loading. However, greater reductions of up to 20% are possible through alignment of laminate balancing axes with principal loading axes. As such, a non-standard angle design strategy is only shown to be warranted if the demonstrated non-uniqueness of optimum designs can be exploited to improve other performance drivers.
|Number of pages||12|
|Journal||Composites Part A: Applied Science and Manufacturing|
|Early online date||28 Sep 2018|
|Publication status||Published - 1 Dec 2018|
- laminate mechanics
- Robust Design