A modular approach to adaptive structures

Abstract

A remarkable property of nastic, shape changing plants is their complete fusion between actuators and structure. This is achieved by combining a large number of cells whose geometry, internal pressures and material properties are optimized for a given set of target shapes and stiffness requirements. An advantage of such a fusion is that cell walls are prestressed by cell pressures which increases, decreases the overall structural stiffness, weight. Inspired by the nastic movement of plants, Pagitz et al. 2012 Bioinspir. Biomim. 7 published a novel concept for pressure actuated cellular structures. This article extends previous work by introducing a modular approach to adaptive structures. An algorithm that breaks down any continuous target shapes into a small number of standardized modules is presented. Furthermore it is shown how cytoskeletons within each cell enhance the properties of adaptive modules. An adaptive passenger seat and an aircrafts leading, trailing edge is used to demonstrate the potential of a modular approach.

Resolving the naturalization strategy of Solidago × niederederi (Asteraceae) by the production of sexual ramets and seedlings

“…Recent data from Austria and Lithuania indicate that S. 9 niederederi forms locally established populations, associated with the parental species (Pagitz and Lechner-Pagitz 2015;Gudžinskas and Ž alneravičius 2016;Pagitz 2016). In Poland, S. 9 niederederi is known from several dozen localities (Pliszko and Zając 2016) and its naturalization is under consideration.…”

Predicting the potential distribution area of Solidago ×niederederi (Asteraceae)

“…(Slavík, 2004;Kiełtyk and Mirek, 2014) as well as the wide naturalized range of S. canadensis s. l. in Europe (Greuter, 2006;Kabuce and Priede, 2010), the hybrid is almost certainly underrecorded in some areas. In addition, recent data from Austria, Poland, and Lithuania suggest that the hybrid is much more frequent than previously thought (Viltrakytė and Karpavičienė, 2014;Pagitz and Lechner-Pagitz, 2015;Gudžinskas and Žalneravičius, 2016;Karpavičienė and Radušienė, 2016). Solidago ×niederederi, which is a perennial plant, forms vigorous and often persistent clonal clumps of stems, similar to those observed in its parental species.…”

“…However, the distribution of S. ×niederederi along the altitudinal gradient in Europe seems to be an interesting subject for further study on its establishment and invasive potential. According to Pagitz and Lechner-Pagitz (2015), some of the highest elevations reached by the hybrid were registered in the Alps (e.g., 885 m a.s.l. in Natters, North Tyrol and 875 m a.s.l.…”

“…Therefore, we selected a total of 83 records (GPS coordinates in the WGS84 system), keeping a minimum distance of 1 km between hybrid occurrence points. The records from Austria and Latvia were obtained from the literature (Pagitz and Lechner-Pagitz, 2015;Gudžinskas and Petrulaitis, 2016), whereas those from Poland were gathered from field surveys conducted by Artur Pliszko in 2013-2016. The records from Lithuania were contributed by Birutė Karpavičienė in accordance with published data (Viltrakytė and Karpavičienė, 2014;Karpavičienė and Radušienė, 2016).…”

Shape optimization of compliant pressure actuated cellular structures

“…It was shown in [13] that these structures can be made from arbitrary engineering materials that range from elastomers to steel. Furthermore, it was shown in [12] that their structural weight can be reduced and the overall stiffness increased with the help of cytoskeletons.…”