C02 – Integrated Fluid-Actuators

Adaptivity is a way to optimize the load-bearing behavior of structures under changing loads. In this case, forces generated by actuators are induced into the structure in a targeted manner. This way, stresses and deformations caused by external effects can be counteracted by stresses and deformations generated through actuation. This reduces the overall stresses and the overall deformation of the structural element.

In the actuation concepts explored so far, the actuator forces are induced into the structural element over the surfaces and boundaries and manipulate the structure as a whole. The integration of actuators into the structural element offers the possibility of local, targeted manipulations exclusively where it is necessary.

In the first funding period, it was numerically and experimentally demonstrated for a concrete beam that local actuation with integrated fluid actuators and full compensation of deflection under load is possible. Since deformations are often decisive criteria for the dimensioning of the component cross-sections in components subjected to bending loads, a significant reduction in cross-section or increase in design load is thus possible.

^{Fluid Actuator Prototype Photo: (c) Christian Kelleter}

^{Functional model of an adaptive bending beam with integrated Fluid Actuators Photo: (c) Christian Kelleter}

^{Experimental investigation of an adaptive bending beam with integrated fluid actuators Photo: (c) Christian Kelleter}

^{Measurement of deflection during experimental investigation Photo: (c) Christian Kelleter}

In the second funding period, the principles are now to be extended for multiaxial spanning slabs. These components generally comprise 50-75 % of the building mass in typical skeleton-frame constructions and thus offer an even greater potential for savings compared to the concrete beams investigated in the first funding period. Furthermore, the additional spatial dimension raises new questions. So far, Integrated actuators that meet the specific requirements of multiaxial load transfer do not exist in mechanical engineering or related domains. The central research question in subproject C02 is as follows:

How must fluid actuators be designed for integration into a plate structure? How can stresses, deformations, and vibrations be reduced with this system?

^{Maximum principal stresses of a passive plate under surface load Photo: (c) Markus Nitzlader}

Within the SFB, subproject C02 is developing a novel concept for the actuation of a primary support structure. New scientific ground is being broken in the research of possible design principles and the component integration of the fluid actuators. The development of the fluid actuators and their integration into a structural element are closely linked and take place in cooperation between the respective disciplines.

The aim of the subproject is to develop actuation and actuator concepts for multiaxially stressed structures subjected to bending loads and to experimentally demonstrate the manipulation of the load transfer.

Subproject Leader

• Prof. Dr.-Ing. Hansgeorg Binz, Institute for Engineering Design and Industrial Design
• Prof. Dr.-Ing. M.Arch. Lucio Blandini, Institute for Lightweight Structures and Conceptual Design
• Prof. Dr.-Ing. Matthias Kreimeyer, Institute for Engineering Design and Industrial Design