Application of an actuator made of a material with a shape memory effect for a transformable space structure

Increase in the operational functionality of space technology leads to the necessity of creating large-sized transformable systems. The development of adequate models which are used in computational experiments to simulate the opening of transformable space structures is of great importance. Significant progress has been made in the field of creating large-sized transformable space antennas: the ratio of the mass of the reflector to its working area has decreased to 0.5–1.5 kg/m2. Despite the significant progress achieved in the design of such structures, the task of ensuring smooth and reliable deployment of large-sized transformable space structures, while ensuring their subsequent functioning, remains important. An important area of applied research in the field of shape memory materials is the creation of thermomechanical force actuators that deploy large-sized space structures. Actuators with shape memory effect makes the opening process easy to control, ensuring its shock-free nature. As an active element of the force actuator, it is proposed to use a wire made of titanium nickelide material with a shape memory effect. To develop a functional model of the actuator’s active element made of a shape memory material, a series of experimental and theoretical studies was carried out

Development of the mathematical model of the force actuator for deployment of large-sized space structures

Abstract A special class of large-sized space systems is formed by transformable structures that have different configurations in transport and operating states. Transformable large-sized space structures are delivered into orbits in a folded transport state and after that they are deployed into operating position. Now problems of the mathematical modeling of deployment dynamics of such systems attract a great interest of scientists. When the structure is transformed, impact dynamic loads arise in the system elements. To ensure a smooth «controlled» opening of the transformable structures and to exclude the dynamic impact loads in their constructed elements, it is proposed to use force actuators made of material with a shape memory effect. Now, to create mechanisms with elements made of the materials with the shape memory effect, the role of experimental methods is very important. Preliminary experimental studies of the force actuator made of such material as titanium nickelide were carried out. Deformation and force characteristics of the actuator obtained in these studies prove the possibility to use it for reliable deployment of the promising transformable space structures. Based on the fulfilled theoretical and experimental studies, the mathematical model describing the force actuator functionality is proposed.</jats:p

ACTUATOR MADE OF MATERIAL WITH SHAPE MEMORY EFFECT FOR DEPLOYMENT OF TRANSFORMABLE SPACE STRUCTURE

Large-sized space structures are delivered into space orbits in a folded, tightly packed form allowing transformation of the structure from the transport position to the unfolded operating state. Deployment of the transformable structure is fulfilled by force drives which are usually various types of springs or electric motors. Designing such space structures, it is necessary to take into account dynamic impact loads that arise during the transformation. To avoid dynamic loads on the deploying structure elements, it is proposed to use actuators made of material with a shape memory effect. An active element made of titanium nickelide wire, which is heated during operation by the electric current passing through it, is used in the actuator. Experimental studies of the actuator active elements have proved that such actuators can be used for deployment of the transformable space structures.</jats:p