This is a past event
Inspired by nature, researchers are trying to create systems and structures that can repair themselves, presenting an adaptive behaviour according to its environment. Among many options of smart sensors and actuators, shape memory alloys (SMAs) are an interesting option since they are easy to manufacture, relatively lightweight, and able of producing high forces or displacements with low power consumption. SMAs belong to the class of smart materials being used in different kinds of applications. The remarkable properties of SMAs are associated with thermoelastic martensitic transformations that are responsible for different kind of complex thermomechanical behaviour of these smart materials. Besides pseudoelastic and shape memory effects, SMAs may demonstrate interesting behaviours as two-way shape memory effect, internal subloops due to incomplete phase transformations, plasticity, transformation induced plasticity, tension-compression asymmetry, rate-dependence behaviour, thermomechanical couplings among other interesting effects related to non-homogeneous characteristics. All these phenomena give a general idea about the complex thermomechanical behaviour of SMAs. This seminar discusses some SMA applications and its thermomechanical behaviour. A novel three-dimensional constitutive model that describes the martensitic phase transformations and is capable of describing the main features of the thermomechanical behaviour of SMAs is presented. The proposed model is developed within the framework of continuum mechanics and generalized standard materials. Numerical investigations of uniaxial and multiaxial tests are conducted exploring different phenomena and potential applications. As applications of the general formulation, finite element method and nonlinear dynamics of SMA systems are treated.
- Speaker
- Prof Marcelo A Savi, Federal University of Rio de Janeiro, Brazil
- Venue
- G011