Robust design of additively manufactured acoustic structures

与材料挤压一样，添加剂制造由于其逐层材料沉积的原理，在设计上提供了新的自由。除其他优点外，这允许在一个部件内组合多种材料，并实现像格子结构这样的底切，而无需额外的组装和连接工艺或后处理。因此，制造和集成具有定制属性的声学有效结构以减少结构和空气中的声音的新的可能性出现了。本研究项目旨在开发一种用于添加制造的声学黑洞和多孔吸声体的稳健设计的方法。声学、工程设计和添加剂制造领域之间紧密联系的合作是阐明声学参数、部件特性、工艺参数和几何设计的事件链--以及工艺-结构-性能关系的先决条件。为了实现这一目标，本研究一方面针对声学黑洞和多孔吸波材料这两个应用实例，研究了声学性能与声学参数之间的依赖关系，以期达到这一目标。另一方面，系统分析了工艺因素对成形零件性能和几何特征的影响。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。其目的是确定敏感和稳健的事件链，以实现以目标为导向的结果部件属性的调整，从而实现低不确定性的功能调整。为了利用这种潜力，所获得的知识将转化为一种方法和设计规则。该方法的验证和对添加剂制造工艺用于稳健生产具有特定性质的声学黑洞和多孔吸波材料的潜力的评估，最终将通过为两个已定义的用例制造演示器来实现。

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.