This work deals with the multi-scale optimisation of composite structures by adopting a general global-local (GL) modelling strategy to assess the structure responses at different scales. The GL modelling approach is integrated into the multi-scale two-level optimisation strategy (MS2LOS) for composite structures. The resulting design strategy is, thus, called GL-MS2LOS and aims at proposing a very general formulation of the design problem, without introducing simplifying hypotheses on the laminate stack and by considering, as design variables, the full set of geometric and mechanical parameters defining the behaviour of the composite structure at each pertinent scale. By employing a GL modelling approach, most of the limitations of well-established design strategies, based on analytical or semi-empirical models, are overcome. The GL-MS2LOS makes use of the polar formalism to describe the anisotropy of the composite at the macroscopic scale (where it is modelled as an equivalent homogeneous anisotropic plate). In this work, deterministic algorithms are exploited during the solution search phase. The challenge, when dealing with such a design problem, is to develop a suitable formulation and dedicated operators, to link global and local models physical responses and their gradients. Closed-form expressions of structural responses gradients are rigorously derived by taking into account for the coupling effects when passing from global to local models. The effectiveness of the GL-MS2LOS is proven on a meaningful benchmark: the least-weight design of a cantilever wing subject to different design requirements. Constraints include maximum allowable displacements, maximum allowable strains, blending, manufacturability requirements and buckling factor.

这项工作通过采用通用的全局局部（GL）建模策略来评估不同尺度下的结构响应，从而应对复合结构的多尺度优化。GL建模方法已集成到复合结构的多尺度两级优化策略（MS2LOS）中。因此，最终的设计策略称为GL-MS2LOS，旨在提出设计问题的非常笼统的表述，而无需在层压板叠层上引入简化的假设，并通过将定义以下各项的完整几何和机械参数作为设计变量复合结构在每个相关尺度下的行为。通过采用GL建模方法，可以克服基于分析或半经验模型的成熟设计策略的大多数局限性。GL-MS2LOS利用极性形式描述了宏观尺度上复合材料的各向异性（在该模型中，等效材料是等效的均质各向异性板）。在这项工作中，在解决方案搜索阶段利用了确定性算法。解决此类设计问题时，面临的挑战是开发合适的公式和专门的运算符，以链接全局和局部模型的物理响应及其梯度。通过考虑从全局模型传递到局部模型时的耦合效应，可以严格得出结构响应梯度的闭式表达式。GL-MS2LOS的有效性在一个有意义的基准上得到了证明：悬臂机翼的最小重量设计要符合不同的设计要求。约束条件包括最大允许位移，