Design and Structural Optimization in Additive Manufacturing - From Isotropy to Anisotropy

增材制造中的设计和结构优化 - 从各向同性到各向异性

• 批准号: 2695259
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2695259
• 关键词: Design; Structural; Optimization; Additive; Manufacturing

This research aims to investigate ways to combine design and structural optimization with anisotropic considerations for additive manufacturing (AM) of lightweight parts with minimized compliance. The scope of this PhD encompassed two major themes: numerical analyses and computational modelling as well as experimental testing and manufacturing. The following three objectives will be the subject of this work:Objective 1: Isotropic topology with orthotropic reinforcement derived from medial axis transformation (MAT)-Content/Numerical Approach: It is envisaged to develop a novel method which combines continuous fibre reinforcement (C-FR) i.e. an effective fibre trajectory planning with topology optimization in an iterative process under the consideration of AM-specific manufacturing constraints. Preliminary investigations and methods on this topic have been published recently (SFF Symp 2018)-Experimental Verification: In order to fabricate these novel AM-designs with tailored fibre paths, a custom multi-material 3D printer enabling fibre reinforced AM (FRAM) was developed and will be further improved. -Potential Applications and Value: This novel approach aims to enhance the performance of AM-parts in terms of stiffness and weight, making them more viable for a wider range of industries. Besides this development towards end-use parts, we seek to gain valuable findings that help streamline the product and development cycles for engineers and designers employing AM processes. Objective 2: Multiscale modelling of mixed architectures with representative volume elements (RVEs) realizing light multifunctional AM-parts-Content/Numerical Approach: This objective aims to develop bio-inspired, light, stiff and robust sandwich structures for AM (see Figure 1). The development of a method which effectively combines topology optimization, C-FR and functionally graded cellular structures will be hereby pursued. From a computational point of view this will include multiscale modelling with dissimilar architectures using RVEs to replicate heterogeneous material characteristics. -Experimental Verification: It is envisaged to employ the above-mentioned custom 3D printer. For the evaluation of the robustness it is intended to conduct for variable loading scenarios.-Potential Applications and Value: This objective aims to combine the two topics in structural optimization for AM which are currently undergoing intense study, namely topology optimization and the employment of cellular structures. This enables the realization of multi-objective structures for AM, which combine e.g. stiffness and strength (fibre reinforced shell) with improved thermal conduction or impact resistance (cellular structure). Possible application can be found in the automotive, the medical engineering and the aerospace sector.Objective 3: Mapping functionally graded lattices to specific mechanical performance-Content/Numerical Approach: The actively researched topic of functionally graded lattices exploits the inherent design freedom of AM for tailored and locally varying material properties. However, in polymer-based AM, certain microstructural grading schemes have not been thoroughly studied yet. For this purpose multiscale modelling approaches using RVEs will be developed helping for a better understanding of these materials and aiding their wider application and adoption. -Experimental Verification: Among others, our custom multi-material 3D will be employed to manufacture advanced microstructurally and compositionally grading cellular structures. Mechanical tests shall help optimizing the computational model. -Potential Applications and Value: These findings will help different industries, which are increasingly adopting cellular structures for the design of their products, to better predict and understand the mechanical characteristics of different cell topologies and therefore enable them to fabricate more efficient structures.

本研究旨在研究将设计和结构优化与各向异性考虑相结合的方法，以最小化合规性来实现轻质零件的增材制造 (AM)。该博士学位的范围涵盖两个主要主题：数值分析和计算建模以及实验测试和制造。以下三个目标将成为这项工作的主题： 目标 1：由中轴变换 (MAT) 衍生的具有正交各向异性增强的各向同性拓扑 - 内容/数值方法：设想开发一种将连续纤维增强 (C-FR) 相结合的新颖方法，即在考虑增材制造特定制造约束的情况下，在迭代过程中进行有效的纤维轨迹规划和拓扑优化。关于这一主题的初步研究和方法最近已发表 (SFF Symp 2018) - 实验验证：为了制造这些具有定制纤维路径的新颖 AM 设计，开发了一种支持纤维增强 AM (FRAM) 的定制多材料 3D 打印机，并将进一步改进。 -潜在应用和价值：这种新颖的方法旨在提高增材制造零件在刚度和重量方面的性能，使其更适用于更广泛的行业。除了针对最终用途零件的开发之外，我们还寻求获得有价值的发现，帮助简化采用增材制造工艺的工程师和设计师的产品和开发周期。目标 2：具有代表性体积单元 (RVE) 的混合架构的多尺度建模，实现轻型多功能 AM 零件内容/数值方法：该目标旨在开发用于 AM 的仿生、轻型、刚性和坚固的夹层结构（见图 1）。我们将致力于开发一种有效结合拓扑优化、C-FR 和功能分级细胞结构的方法。从计算的角度来看，这将包括使用 RVE 复制异质材料特性的不同架构的多尺度建模。 -实验验证：设想采用上述定制3D打印机。为了评估其鲁棒性，旨在对可变负载场景进行评估。-潜在应用和价值：该目标旨在将目前正在深入研究的增材制造结构优化中的两个主题结合起来，即拓扑优化和细胞结构的使用。这使得能够实现 AM 的多目标结构，其中结合了例如刚度和强度（纤维增强外壳），具有改进的导热性或抗冲击性（蜂窝结构）。可能的应用可以在汽车、医学工程和航空航天领域找到。 目标 3：将功能梯度晶格映射到特定的机械性能 - 内容/数值方法：功能梯度晶格的积极研究主题利用增材制造固有的设计自由度来定制和局部变化的材料特性。然而，在基于聚合物的增材制造中，某些微观结构分级方案尚未得到彻底研究。为此，将开发使用 RVE 的多尺度建模方法，帮助更好地理解这些材料并帮助其更广泛的应用和采用。 -实验验证：除其他外，我们的定制多材料 3D 将用于制造先进的微观结构和成分分级蜂窝结构。机械测试应有助于优化计算模型。 -潜在应用和价值：这些发现将帮助越来越多地采用蜂窝结构进行产品设计的不同行业更好地预测和理解不同蜂窝拓扑的机械特性，从而使他们能够制造更高效的结构。