Towards a Design for Acoustics (DFAc) methodology

Handling of acoustic properties of products are of increasing relevance in product development. Compared to other properties like weight or manufactorability, acoustics presents a complex property relevant in the use phase of a product and affected by the actual operation conditions. In order to support determination, evaluation and optimization of acoustic properties in early design stages in this contribution fundamentals for a Design for Acoustic methodology are outlined. Therefore, basic elements of DFX methodologies and the evolution of the Design for Manufacture methodology are described. Against this background premises and fields of research are defined to establish a Design for Acoustics methodology.Die akustischen Eigenschaften gewinnen in der Produktentwicklung zunehmend an Bedeutung. Im Vergleich zu anderen Eigenschaften wie Gewicht oder Herstellbarkeit sind diese Eigenschaften komplex und insbesondere in der Nutzungsphase eines Produkts relevant. Gleichzeitig werden die Eigenschaften durch die tatsächlichen Betriebsbedingungen beeinflusst. Um die Ermittlung, Bewertung und Optimierung akustischer Eigenschaften in frühen Entwurfsphasen zu unterstützen, werden in diesem Beitrag Grundlagen für eine Design for Acoustics Methodik skizziert. Zunächst werden grundlegende Elemente von DFX Methodiken und die Entwicklung der Design-for-Manufacturing Methodik beschrieben. Ausgehend hiervon werden Prämissen und Forschungsfelder definiert, um eine Design for Acoustics Methodik zu etablieren

Konstruktive Optimierung des Freilauf-Doppelprüfstandes

Die Lebensdauer von Freiläufen unter reiner Torsionsbelastung kann von Anwendern und Herstellern realistisch abgeschätzt werden. Die in der Praxis häufig auftretenden parasitären Zusatzlasten führen zu einem verfrühten Ausfall des Freilaufs, da diese in der Auslegung bisher nicht genau berücksichtig werden können. Im Rahmen eines Forschungsvorhabens soll diese Auslegungsgrundlage geschaffen werden. Der bereits bestehende Prüfstand zum Aufbringen und Messen von Radiallasten an Freiläufen soll für die weitere Forschung konstruktiv angepasst werden. Primär wird hierfür die Prüflingsaufnahme umgestaltet, um einen zentralen Prüfraum mit direkter Messaufnahme zu schaffen.The lifespan of Freewheels due to solely torsional load can be estimated realistically by the user as well as the manufacturer. In practice the torsional loads are overlaid with additional loads, resulting from radial forces or tilted tracks, which causes a premature failure. Until today, the resulting reduction of lifespan cannot be predicted precise. A design basis is to be created as part of a research project for these circumstances. The design of the existing test rig for applying and measuring radial loads on freewheels is to be adapted for further research. Primarily, the test piece fixture will be redesigned to create a central test area with direct measurement fixture

Der Querelastizitätsmodul kunststoffummantelter Drahtseile

In dem Forschungsprojekt „Lifetime Coated Ropes“ ist die Eignung kunststoffummantelter Drahtseile für die Mehrlagenwicklung untersucht worden. Eine wichtige Untersuchung war die Ermittlung des Querelastizitätsmoduls, sowie der Einfluss des Kunststoffmantels auf die Quersteifigkeit. Hier wird auf die Untersuchungsergebnisse des einlagigen Seils eingegangen.In the research project "Lifetime Coated Ropes", the applicability of plastic-coated wire ropes for multi-layer spooling has been examined. An important part of the examination was the determination of the lateral modulus of elasticity, as well as the influence of the plastic coating on the lateral stiffness. Here we discuss the findings of the examination on single layer ropes

Druckkammlagerung: Eingrenzung der Verlustleistungsreduktion bei optimaler Wälzlagerwahl

Untersucht werden Wälzlagerverlustleistungen und -kosten für Konfigurationen mit und ohne Druckkammlagerung. Aus dem gesamten Herstellerkatalog werden jeweils die verlustleistungs- oder kostenoptimalen Lager für eine umfangreiche Variation von Randbedingungen gewählt.Roller bearing power loss and cost are analyzed for configurations with and without thrust collars. Optimal bearings concerning efficiency or cost are selected from the entire manufacturer’s catalogue for an extensive variation of situations

Liquefaction and Paleo-liquefaction in Christchurch, New Zealand

Liquefaction during the 4th September 2010 Mw 7.1 Darfield earthquake and large aftershocks in 2011 (Canterbury earthquake sequence, CES) caused severe damage to land and infrastructure within Christchurch, New Zealand. Approximately one third of the total CES-induced financial losses were directly attributable to liq- uefaction and thus highlights the need for local and regional authorities to assess liquefaction hazards for present and future developments. This thesis is the first to conduct paleo-liquefaction studies in eastern Christchurch for the purpose of de- termining approximate return times of liquefaction-inducing earthquakes within the region. The research uncovered evidence for pre-CES liquefaction dated by radiocarbon and cross-cutting relationships as post-1660 to pre-1905. Additional paleo-liquefaction investigations within the eastern Christchurch suburb of Avon- dale, and the northern township of Kaiapoi, revealed further evidence for pre-CES liquefaction. Pre-CES liquefaction in Avondale is dated as post-1321 and pre-1901, while the Kaiapoi features likely formed during three distinct episodes: post-1458 and possibly during the 1901 Cheviot earthquake, post-1297 to pre-1901, and pre-1458. Evaluation of the liquefaction potential of active faults within the Can- terbury region indicates that many faults have the potential to cause widespread liquefaction within Avondale and Kaiapoi. The identification of pre-CES liquefac- tion confirms that these areas have previously liquefied, and indicates that residen- tial development in eastern Christchurch between 1860 and 2005 occurred in areas containing geologic evidence for pre-CES liquefaction. Additionally, on the basis of detailed field and GIS-based mapping and geospatial-statistical analysis, the distribution and severity of liquefaction and lateral spreading within the eastern Christchurch suburb of Avonside is shown in this study to be strongly in uenced by geomorphic and topographic variability. This variability is not currently ac- counted for in site-specific liquefaction assessments nor the simplified horizontal displacement models, and accounts for some of the variability between the pre- dicted horizontal displacements and those observed during the CES. This thesis highlights the potential applications of paleo-liquefaction investigations and ge- omorphic mapping to seismic and liquefaction hazard assessments and may aid future land-use planning decisions