Session: 04-13 SS: Active Hybrid Composites

Paper Number: 167830

167830 - Fundamental Characteristics and Adjustment Parameters of Shape Adaptive Shape Memory Alloy Hybrid Composites 

This paper presents fundamental electro-thermomechanical characteristics and geometric and material-related adjustment parameters of shape adaptive Shape Memory Alloy Hybrid Composites (SMAHCs) for out-of-plane bending configurations. These characteristics are derived from a theoretical, transient multi-physical modeling approach that allows for the prediction of actuator performance also in the time domain. The model is experimentally verified across a wide range of relevant ambient conditions. SMAHCs are a class of active smart material composites capable of converting electrical or thermal input into mechanical output in the form of macroscopic deformation. Despite their compact size and high actuator power density, these actuators are distinguished by their robustness against media, silent operation, high single-stroke frequency, sensor capabilities and maintenance-free operation, making them suitable for many applications. Conversely, the relatively low cyclic operating frequency and elevated power consumption of this actuator class may present challenges for certain applications.

The unique advantages in applications requiring controlled deformation, making them ideal for various engineering fields. The bending actuation concept has already proven its potential in various engineering disciplines, such as deployable vortex generators for aerodynamic optimization, locking mechanisms for consumer goods, smart air vents in automotive applications, and as a robust and space-saving alternative to conventional actuators.

Understanding how to tailor the characteristics of SMAHCs based on ambient conditions is crucial for engineers to determine the suitability of the actuator for a given application and optimal dimensioning. This work provides a comprehensive overview of the relevant material-specific and geometric parameters for adjusting the properties of shape adaptive SMAHCs. The focus is on actuators comprised of three layers: the active layer containing Nickel-Titanium shape memory wires, a stiff base layer, and an interlayer for distance adjustment between the active and base layers. Additionally, anchor systems for the SMA wires are required to withstand high shear forces in the edge areas, which are less important for actuator performance.

Relevant parameters for actuator performance include the thickness and stiffness of the base layer, the overall length of the SMAHC, the thickness of the interlayer, the SMA wire volume content in the active layer, and the thermal properties of the interlayer and the performance parameters of the SMA. Additionally, the properties of SMAHCs under the influence of external mechanical loading, ambient temperature, and power supply scenarios are provided. The fundamental characteristics derived can be used for a more generalized classification, comparing SMAHCs within other actuator systems.

Overall, this paper aims to provide a comprehensive guide for engineers and researchers to optimize the performance of SMAHCs, ensuring their effective integration into diverse technological systems.

Presenting Author: Max Kaiser Leibniz-Institut für Verbundwerkstoffe GmbH

Presenting Author Biography: -Education:
- 2017: Diploma Engineer, TU Kaiserslautern (TU KL), Diploma thesis: Control system for Shape Memory alloy hybrid composites (SMAHC)as Vortex generators, field-tested on glider plane with DG Flugzeugbau, Alumni Preis for Best Student Thesis
- 2023: PhD, Leibniz-Institut for Composites (L-IVW), Thesis: Transient multiphysical modeling of shape-adaptive SMAHC, SAMPE Best Thesis Award Finalist

2017 to 2025 as research assistant and senior researcher at L-IVW: Various industry and publicly funded projects on the development and implementation of applications with shape-adaptive SMAHC technology