Robust design of additively manufactured acoustic structures

增材制造像材料挤压一样，由于其逐层沉积材料的原理，为设计提供了新的自由度。在其他好处中，这允许在一个部件内组合多种材料，并实现像晶格结构这样的切口，而无需额外的组装和连接过程或后处理。因此，制造和集成具有定制性能的声学有效结构以减少结构传播和空气传播的声音的新可能性出现了。本研究项目旨在开发一种增材制造声黑洞和多孔吸收器的稳健设计方法。声学、工程设计和增材制造领域之间紧密联系的合作是阐明声学参数、零件特性、工艺参数和几何设计之间的事件链以及工艺-结构-性能关系的先决条件。目前，由于对工艺参数选择、几何形状定义和声学相关特性之间的固有敏感性缺乏详细的了解，对具有确定参数的声学结构进行系统和稳健的设计仍然受到限制。为了实现这一目标，本课题以声学黑洞和多孔吸波体两种用例为例，一方面研究了声学特性与声学参数之间的依赖关系，以实现声学功能的具体调整。另一方面，系统地分析了工艺对零件性能和几何特征的影响因素。通过数值和实验研究系统地确定了事件链关系，并为材料挤压制造的声学结构的稳健设计奠定了基础。目的是识别敏感和鲁棒的事件链，以实现对结果部分属性的目标导向调整，从而实现具有低不确定性的函数。为了利用这种潜力，所获得的知识将被转化为一种方法和设计规则。方法的验证和增材制造工艺对声学黑洞和具有特定性能的多孔吸收剂的强大生产的潜力的评估将最终通过为两个定义的用例制造演示品来实现。

Additive Manufacturing like Material Extrusion, offers new freedom in design, due to its principle of layer-by-layer material deposition. Among other benefits, this allows a combination of multiple materials within one part and the realization of undercuts like lattice structures, without additional assembly and joining processes or post-processing. Thus, new possibilities arise for manufacturing and integrating acoustically effective structures with tailored properties to reduce structure-borne and airborne sound.This research project aims to develop a methodology for the robust design of additively manufactured acoustic black holes and porous absorbers. The closely linked cooperation between the fields of acoustics, engineering design and additive manufacturing is the prerequisite for elucidating the event chains – also process-structure-property relations – of acoustic parameters, part properties, process parameters and the design of geometry. A systematic and robust design of acoustic structures with defined parameters is currently still limited by a lack of detailed knowledge regarding the inherent sensitivities between process parameter selection as well as geometry definition and the resulting acoustics-relevant properties.In order to achieve this goal, the dependencies between part properties and acoustic parameters for the specific adjustment of the acoustic function are investigated in this research project for the two use cases of acoustic black holes and porous absorbers, on the one hand. On the other hand, the process-specific influencing factors on the resulting part properties and the geometric features are systematically analyzed. The event chain relationships are systematically determined by means of numerical and experimental investigations and are the basis for a robust design of acoustic structures manufactured by material extrusion. The aim is to identify sensitive and robust event chains in order to achieve a goal-oriented adjustment of the resulting part properties and, thus, of the function with a low uncertainty. To utilize this potential, the knowledge gained will be transferred into a methodology and design rules. The validation of the methodology and the evaluation of the potential of additive manufacturing processes for a robust production of acoustic black holes and porous absorbers with specific properties will finally be achieved by the manufacturing of demonstrators for the two defined use cases.