A framework for design and optimization of tapered composite structures. Part II: Enhanced design framework with a global blending model

Abstract

A B S T R A C TA high-dimensional variable design space in optimization problems for tapered composite structures presupposes a development of efficient computational techniques to improve the design efficiency and flexibility. In this work, a mathematical model for optimization of tapered composite structures with buckling and manufacturing constraints is developed, then a ply-drop-based global blending model (GBM) is suggested to address the layers' addition/deletion and blending problems. Within the framework proposed in Part I of this work (Compos Struct, 2016, 154: 106-128), by incorporating the global blending model, operations of add-layer, exchange-blend and sequence-adjustment are revised and enhanced. The GBM can not only characterize the global blending property, but also guide the maximum blending design. Accordingly, the design framework is simplified, and its computational cost is reduced significantly since there is no iteration of shape prediction and stacking-sequence optimization procedure. An 18-panel benchmark problem is adopted to verify the enhanced design framework, as compared with previous design results, the obtained better solution with higher efficiency implies its feasibility and potential for effective design of tapered composite structures.

Variable-stiffness optimization of CFRP body panels for body-in-white

“…Note the symmetric layup requirement and the balance requirement are implemented to avoid extension-bending coupling and shear-extension coupling in the component. [23][24][25] Thus, by carefully structuring the design process, the lamination can be designed as a symmetric layup with an odd number of layers to improve the structural efficiency without violating the intent of symmetry and balance manufacturing requirements.…”

Optimal design of tapered composite structures with a dynamic boundary subset blending model

“…To broaden the design space in the optimization, Fan 16 implemented the continuity constraint through the summarized continuity rules; newly constructed chromosomes were utilised in the evolutionary optimization of the global stacking sequence of composite structures, which can avoid the problem of most blending models that laminates with identical thicknesses must have the completely same layups. Considering multiple manufacturing constraints (all plies from a thinner panel must cover the whole structure for continuity constraint), Jing 20 proposed a novel framework based on a sequential permutation table (SPT) method and a global shared-layer blending (GSLB) method. However, the optimal design did not obey the classical subset blending rule that the plies composing the thinner region should be a subset of the ones of the thicker region between two adjacent regions.…”

Ply-overlap Fiber Reinforced Plastic Connection Structure Design and Discrete Optimization

“…总结了目前复合材料铺层优化刚 度 变 化 问 题 及 研 究 现 状 。 STEGMANN 等 和 SØRENSEN 等先后提出了基于梯度的离散材料优 化(Discrete material optimization,DMO)方法 [2] 和离 散 材 料 与 厚 度 优 化 (Discrete material thickness optimization,DMTO)方法 [3] ，考虑到铺层材料各项参 数和产品厚度设计优化，通过对整体区域的划分和 各个子区域设计优化，采用不同纤维取向铺层设计方 案，在各子域设计空间上通过复合材料拼接铺层进行 研究。LUND [4] 基于上述方法，在优化计算过程中引入 材料失效准则，从设计结构刚度方面考虑，保证了复 合铺层板的整体结构性能， 使结构优化更准确和可靠。 KIYONO 等 [5] 把复合材料纤维取向作为研究重点，通 过离散材料铺层计算优化设计变量，更有利于优化问 题的收敛并实现了纤维排列的连续性。 结构件轻量化设计使得复合材料铺层优化方法 在拼接板上得到了广泛研究和应用。ZHOU 等 [6] 从 不同设计角度提出了一种复合材料铺层优化方案。 针对变厚度物理连接约束的铺层顺序优化研究，在 分阶段设计的基础上，IRISARRI 等 [7] 介绍了用于叠 层复合结构的堆叠序列表(Stacking sequence table， SST)混合优化方法，并据此设计了可广泛应用的设 计指南，在满足设计约束的同时取得了良好的轻量 化 实 施 效 果 。 JING 等 [8][9] 分 别 应 用 顺 序 排 列 表…”