Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
EXPERIMENTAL VALIDATION OF A BOND GRAPH MODEL OF A SHAPE MEMORY ALLOY WIRE ACTUATOR
Submission Author:
Lucas Olinda , SP , Brazil
Co-Authors:
Lucas Olinda, Eurípedes Nóbrega
Presenter: Lucas Olinda
doi://10.26678/ABCM.COBEM2021.COB2021-1106
Abstract
Shape memory alloys (SMA) are smart materials that, after undergoing apparently plastic deformation, have the ability to recover their geometry when subjected to a thermal stimulus. However, the mathematical modeling of the SMA is complex due to its non-linear behavior, which make it difficult to simulate SMA-based actuated devices designs. Thus, this paper aims to develop and test a mathematical model of an SMA wire using the Bond Graph technique, a preferred way to facilitate modeling of multi-domain systems. For this purpose, an SMA wire with a diameter of 0.3 mm and a length of 250 mm was adopted as an actuator to be analyzed. To identify its respective parameters an experimental workbench was built to perform thermomechanical tests, applying heat through a controlled electrical current. After a number of excitation cycles, the wire acquired a stable behavior, then a series of experiments were conducted to identify the parameters that are used in the bond graph model. The model results were compared to those acquired using the experimental test bench, showing a good similarity between the respective values, such as the maximum displacement and the duration of heating and cooling of the actuator during each operating cycle, thus validating the complete procedure. Finally, a hydraulic SMA driven diaphragm minipump was designed and modeled, and will be developed in the next steps of this work.
Keywords
Shape Memory Alloy, Bond Graph, modeling, Dynamic system
