This review article gives an overview of the new and quickly developing field of shape memory alloy (SMA) actuators in smart structures. The focus is on the aspects of modeling and simulation of such structures, a task that goes beyond classical modeling approaches as it has to combine constitutive modeling with structural and control aspects in a highly interdisciplinary way. We review developments in each of these fields, trying to combine them into a smooth picture of how to treat the problem efficiently. After a discussion of modeling aspects with particular regard to actuator applications, the simulation of standard feedback control methods is demonstrated. Subsequently, model based methods from optimal control theory are presented, accounting for the strongly nonlinear and hysteretic material behavior of SMAs. Real-time optimal control methods are introduced and, finally, aspects of finite element implementation of an SMA actuator model are discussed and illustrated by the simulation of an adaptive aircraft wing. This review article cites 155 references.

Solid‐state cooling is an environmentally friendly, no global warming potential alternative to vapor compression‐based systems. Elastocaloric cooling based on NiTi shape memory alloys exhibits excellent cooling capabilities. Due to the high specific latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. The small required work input enables a high coefficient of performance. An overview of elastocaloric cooling from basic principles, such as elastocaloric cooling cycles, material characterization, modeling, and optimization, to the design of elastocaloric cooling devices is presented. Current work performed within the DFG (Deutsche Forschungsgemeinschaft) Priority Program SPP 1599 “Ferroic Cooling”, which is focused on the development and realization of a continuously operating elastocaloric cooling device, is highlighted. The cooling device operates in a rotatory mode with wires under tensile loading. The design allows maximization of cooling power by suitable wire diameter scaling as well as efficiency optimization by implementing a novel drive concept. Finally, computer‐aided design (CAD) models of the discussed solid‐state air cooling device are presented.

This paper deals with a positioning system based on a dielectric electro-active polymer membrane. The motion is generated by the deformation of the membrane caused by the electrostatic compressive force between two compliant electrodes applied on the surface of the polymer. This paper proposes a detailed electro-mechanical nonlinear model of the system, which is subsequently used to develop (in both time and frequency domains) various model-based feedback control laws. Accurate modeling is useful to compensate the nonlinear behavior of the actuator (caused by the material characteristics and geometry) and obtain PID controllers providing precise tracking of steps or sinusoidal reference signals. The various design strategies are compared on various experimental tests.