Using Influence Matrices as a Design and Analysis Tool for Adaptive Truss and Beam Structures

Abstract

Due to the already high and still increasing resource consumption of the building industry, the imminent scarcity of certain building materials and the occurring climate change, new resource-and emission-efficient building technologies need to be developed. This need for new technologies is further amplified by the continuing growth of the human population. One possible solution proposed by researchers at the University of Stuttgart, and which is currently further examined in the context of the Collaborative Research Centre (SFB) 1244 Adaptive Skins and Structures for the Built Environment of Tomorrow is that of adaptivity. The integration of sensors, actuators, and a control unit enables structures to react specifically to external loads, when needed (e.g., in the case of high but rare loads). For example, adaptivity in load-bearing structures allows for a reduction of deflections or a homogenization of stresses. This in its turn allows for ultra-lightweight structures with significantly reduced material consumption and emissions. To reach ultralightweight structures, i.e., adaptive load-bearing structures, two key questions need to be answered. First, the question of optimal actuator placement and, second, which type of typology (truss, frame, etc.) is most effective. One approach for finding the optimal configuration is that of the so-called influence matrices. Influence matrices, as introduced in this paper, are a type of sensitivity matrix, which describe how and to which extend various properties of a given load-bearing structure can be influenced by different types of actuation principles. The method of influence matrices is exemplified by a series of studies on different configurations of a truss structure.

Adaptive Hüllen und Strukturen

“…Eine weitere Methode zur Analyse und Synthese adaptiver Tragwerke ist die mit Einflusslinien verwandte Methode der Einflussmatrizen [12]. Diese beschreiben, wie sich eine bestimmte Zustandsgröße (z.…”

“…Diese Unterscheidung ist wichtig, da die Art der Aktuierung einen erheblichen Einfluss auf die Wirkung des Aktors hat [12]. Im Fall der seriellen Aktuierung (Bild 6) wird der Aktor auch im passiven (ausgeschalteten) Zustand am Lastabtrag beteiligt.…”

An Actuator Concept for Adaptive Concrete Columns

“…Figure 2 shows the schematic application of the adaptive concrete columns under an external compressive (blue) or tensile (red) axial force 𝐹 and the resulting stresses. The field of adaptive civil engineering structures distinguishes between two main categories of linear actuation concepts due to the differences in mechanical behavior and adaptation potentials [33]: actuation in series and parallel actuation [34]. One major difference, which is also relevant for the design of actuators, is the difference in the loading of the actuator.…”

Adaptive Concrete Beams Equipped With Integrated Fluidic Actuators

“…This article on integrated actuators focuses on reducing deflection and the bending moment; therefore, the normal and shear forces are not discussed further. The parallel and serial actuation of truss structures is examined in more detail in Steffen et al (2020).…”