Stress-based topology optimization for fiber composites with improved stiffness and strength: Integrating anisotropic and isotropic materials
Stress-based topology optimization for fiber composites with improved stiffness and strength: Integrating anisotropic and isotropic materials
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DOI：
10.1016/j.compstruct.2023.117041
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发表时间：
2023-05
影响因子：
6.3
通讯作者：
R. Kundu;X. Zhang
中科院分区：
文献类型：
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作者：
R. Kundu;X. Zhang
纤维增强材料为轻质复合材料结构提供了高刚度和强度质量比。为了设计刚性、强度和轻质的纤维增强复合材料结构，我们提出了一种多材料各向异性应力约束拓扑优化框架，该框架同时优化几何形状、各向异性（即，正交各向异性）和各向同性材料相，以及各向异性相中纤维增强物的局部取向。为了在刚度和强度方面实现高性能，我们发现需要各向同性和各向异性材料：各向异性材料在单轴构件中是优选的，以增加刚度，而各向同性材料在多轴应力接头中是至关重要的，以提高强度。我们引入多材料插值方案来表征由各向异性和各向同性材料组成的复合材料的刚度和强度。强度的表征是通过一种新的基于载荷因子的屈服函数插值，始终集成各向异性蔡武和各向同性冯米塞斯屈服准则。我们优化应力敏感域考虑材料的刚度和强度各向异性以及多个负载情况下的各种水平。所提出的框架中的各向异性应力约束有效地通知几何形状，以减少纤维复合材料中的应力集中。所提出的框架提供了一个合理的设计范例，利用不同的刚度和强度性能的各向异性和各向同性材料的复合材料结构，潜在的各种工程应用中受益。
Fiber-reinforced materials offer high stiffness- and strength-to-mass ratios to lightweight composite structures. To design stiff, strong, and lightweight fiber-reinforced composite structures, we propose a multimaterial anisotropic stress-constrained topology optimization framework that simultaneously optimizes geometry, distribution of anisotropic (i.e., orthotropic) and isotropic material phases, and local orientations of fiber reinforcements in the anisotropic phase. To achieve high performance in both stiffness and strength, we discover that both isotropic and anisotropic materials are needed: anisotropic materials are preferred in uniaxial members to increase stiffness, while isotropic materials are crucial at multi-axially stressed joints to enhance strength. We introduce multimaterial interpolation schemes to characterize both the stiffness and strength of composites made up of anisotropic and isotropic materials. The characterization of strength is enabled by a novel load factor-based yield function interpolation that consistently integrates anisotropic Tsai–Wu and isotropic von Mises yield criteria. We optimize stress-sensitive domains considering materials with various levels of stiffness and strength anisotropy as well as multiple load cases. The anisotropic stress constraints in the proposed framework effectively inform geometries to reduce stress concentration in fiber composites. The proposed framework provides a rational design paradigm for composite structures, capitalizing on dissimilar stiffness and strength properties of anisotropic and isotropic materials, to potentially benefit various engineering applications.