Double–Double (DD) laminates, incorporating a repetition of sub-plies featuring two groups of balanced angles, offer broad design flexibility together with the ease of design and manufacturing. In this work, a novel optimization design method is proposed for DD composite laminates based on multi-material topology optimization. First, the uniform multiple laminates interpolation (UMLI) model is proposed to describe the certainty of the stacking direction in multi-layer composite structures, inspired by the interpolation model in multi-material topology optimization. Specifically, the stiffness matrices of all alternative angle combinations of laminates are interpolated to form virtual laminates. The UMLI model eliminates the need for adding interlayer constraints during the optimization process. Then, the optimization problem is defined to minimize the compliance of the composite structures and is solved using the gradient-based optimization algorithm. Finally, the proposed method is applied to the design of the composite stiffened panel, the composite Unmanned Aerial Vehicle (UAV) wing, and the rear fuselage. The results demonstrate that the UMLI model and proposed optimization method have considerable potential in the angle optimization design of multi-layer structures.

中文翻译：

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基于多材料拓扑优化的双-双层合板均匀多层板插值模型及设计方法


双层 （DD） 层压板采用重复的子层，具有两组平衡角度，提供广泛的设计灵活性以及设计和制造的便利性。本工作提出了一种基于多材料拓扑优化的 DD 复合材料层合板优化设计方法。首先，受到多材料拓扑优化中插值模型的启发，提出了均匀多层层压板插值 （UMLI） 模型来描述多层复合材料结构中堆叠方向的确定性。具体来说，层合板的所有替代角度组合的刚度矩阵都经过插值以形成虚拟层合板。UMLI 模型消除了在优化过程中添加层间约束的需要。然后，定义优化问题以最小化复合结构的柔度，并使用基于梯度的优化算法进行求解。最后，将所提方法应用于复合材料加筋板、复合材料无人机（UAV）机翼和后机身的设计中。结果表明，UMLI 模型和所提出的优化方法在多层结构的角度优化设计中具有相当大的潜力。