Smart Materials and Structures · 2010 · 105 citations · 24 references
EngineeringMaterials EngineeringMaterials ScienceActuatorsPhase TransformationsSolid MechanicsComputational ThermomechanicsMechanical Property SimulationShape Memory Alloy ActuatorsSolid Mechanics ApplicationsThermoelasticityThermomechanical AnalysisHelical SpringsShape MemoryShape-memory AlloysShear BehaviorSmart ActuatorsThermomechanical BehaviorThermomechanical EffectsThermomechanical Properties
Shape memory alloys are smart materials whose stress‑ or temperature‑induced phase transformations enable versatile actuators, with springs frequently employed as functional elements. This contribution investigates the modeling, simulation, and experimental analysis of SMA helical springs. The authors use a one‑dimensional constitutive model of SMA shear behavior combined with a classical linear‑elastic spring formulation, solve it with an operator‑split numerical scheme, and validate the results through experiments under varied thermomechanical loadings that capture shape‑memory and pseudoelastic effects. Numerical simulations closely match experimental data, demonstrating that the proposed model accurately captures the general thermomechanical behavior of SMA springs.
Shape memory alloys (SMAs) belong to the class of smart materials and have been used in numerous applications. Solid phase transformations induced either by stress or temperature are behind the remarkable properties of SMAs that motivate the concept of innovative smart actuators for different purposes. The SMA element used in these actuators can assume different forms and a spring is an element usually employed for this aim. This contribution deals with the modeling, simulation and experimental analysis of SMA helical springs. Basically, a one-dimensional constitutive model is assumed to describe the SMA thermomechanical shear behavior and, afterwards, helical springs are modeled by considering a classical approach for linear-elastic springs. A numerical method based on the operator split technique is developed. SMA helical spring thermomechanical behavior is investigated through experimental tests performed with different thermomechanical loadings. Shape memory and pseudoelastic effects are treated. Numerical simulations show that the model results are in close agreement with those obtained by experimental tests, revealing that the proposed model captures the general thermomechanical behavior of SMA springs.
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Gill A. Pratt, Matthew M. Williamson · 2002 · 2.2K citations
Engineering, Mechanical Engineering, Robotics Engineering +17