Stress and stiffness-based topology optimization of two-material thermal structures
Stress and stiffness-based topology optimization of two-material thermal structures
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DOI：
10.1016/j.compstruc.2021.106641
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发表时间：
2021-11
影响因子：
4.7
通讯作者：
A. Tamijani
中科院分区：
文献类型：
--
作者：
A. Tamijani
梯度添加剂制造技术能够将具有梯度组成的多种材料实现到单个部件的制造中。这提供了一个独特的机会来控制材料的性能，如热膨胀、杨氏弹性系数和屈服应力，并创造出一种否则无法实现的结构。为了利用这一能力，开发了基于密度的拓扑优化框架，对不同材料的空间分布、界面和结构布局进行优化，以提高结构的刚度和应力。提出了实现这些目标的内插方案，并讨论了三个层次的复杂性，即多材料设计、依赖于设计的热载荷和应力约束。通过三个算例对该框架进行了评估，并对优化后的基于刚强度的拓扑结构和材料组成进行了验证。最后对单材料优化设计和多材料优化设计进行了比较。结果表明，在满足失效约束的同时，多材料设计的柔度较低，对于单材料结构而言，要么是不可行的，要么是以显著较高的权重实现的。
Gradient additive manufacturing techniques are capable of implementing multiple materials with graded compositions into the fabrication of a single component. This provides a unique opportunity to control the properties of materials, such as thermal expansion, Young’s modulus, and yield stress, and create a structure that otherwise would be infeasible. To utilize this capability, a density-based topology optimization framework is developed to optimize the spatial distribution of different materials, their interfaces, and the structural layout in order to enhance both the stiffness and the stress. Interpolation schemes to achieve these objectives are proposed, and the three levels of complexities, i.e., multi-material designs, design-dependent thermal loads, and stress constraints, are addressed. The framework is evaluated using three numerical examples, and the optimized stiffness and strength-based topology and material composition are demonstrated. Finally, the single-material and multi-material optimized designs are compared. The results show that the low compliance of the multi-material designs, while satisfying the failure constraint, was either infeasible or was achieved with a significantly higher weight for single-material structures.