Finite Element Analysis of Smart Structures Based on Shape Memory Alloys.

Kurzfassung

Smart structures are currently being developed within the DLR project ARES (Actively Reacting Flexible Structures), using integrated multifunctional actuators and sensors for shape control, vibration control, and alignment precision control. Shape memory alloys are a candidate material for use in actuators. For shape memory alloy material behavior, a nonlinear finite element procedure is developed which incorporates a thermomechanically derived constitutive law. The constitutive equations that include the necessary internal variables to account for the material transformations are utilized in a finite element procedure that captures the unique shape memory alloy responses of pseudoelasticity and the shape memory effect. Test cases are presented to illustrate the potential of the finite element procedure. Two further applications are examined: the use of a shape memory alloy ring as a pipe connector and the eigenfrequency tuning of a composite beam withembedded shape memory alloy wires. The results of the analyses correlate well with analytical results.