Design methodology for the holistic optimization of truss structures with additively manufactured nodes under consideration of manufacturing and assembly restrictions

桁架结构是一种经济、刚性和有效的轻量化设计方法，特别是在希望充分利用材料的强度和刚度的情况下。使用纤维增强材料作为支撑是常见的做法，但支撑之间的连接构件-所谓的节点-通常是由金属制成的，在设计方面是一个挑战，特别是优化的桁架结构。在本研究项目中，考虑到外加剂制造的纤维增强节点的特殊要求，正在开发、实施和评估桁架结构的整体优化方法。该方法考虑了节点附加制造的特殊要求和自由度，以及各向异性材料和离散元件尺寸对总体设计的影响。在整体结构优化和连接单元(节点)拓扑优化研究的基础上，对结构的节点和装配进行了详细的研究。将确定装配的相关参数，与结构的轻量化潜力相同。然后将所得结果用于直接考虑制造和装配约束的纤维增强材料和附加制造节点的桁架结构的整体优化方法。此外，还将研究桁架结构的结构健康监测方法，以便将其用于故障关键应用。最后，利用合适的传感器技术对所提出的节点和桁架结构原型进行了制造和实验验证，以确定新设计方法的局限性和即将到来的研究潜力。

Truss structures are an economical, stiff and effective lightweight design method, especially if complete utilization of the material with regard to strength and stiffness is desired. The use of fibre-reinforced materials for the struts is common practice but connecting elements between the struts - so-called nodes - are usually made of metals and are a challenge in terms of design, especially with optimized truss structures. In the present research project, a method for the holistic optimization of truss structures is being developed, implemented and evaluated, taking the special requirements of additive manufactured, fibre-reinforced nodes into account. The method accounts for the special requirements and freedom due to additive manufacturing of the nodes and the influence of anisotropic material and discrete component sizes on the overall design. Based on studies on the optimization of the overall structure and topology optimization of the connecting elements (nodes), the joints and the assembly of the structure is investigated in detail. Relevant parameters for assembly will be identified, same as the lightweight potential of the structure. The gained results are then used to develop a holistic optimization method for truss structures made of fibre-reinforced materials and additively manufactured nodes, taking manufacturing and assembly restrictions directly into account. In addition, methods for structural health monitoring of truss structures will be investigated in order to allow their use in failure-critical applications. Finally, the proposed nodes and a prototype of a truss structure are manufactured and experimentally validated with appropriate sensor technology in order to identify the limits of the new design approach and the upcoming research potential.