THERMODYNAMICALLY CONSISTENT THERMOMECHANICAL MODELING OF KINETICS OF MACROSCOPIC PHASE TRANSITION IN SMA USING PHASE FIELD THEORY

摘要: Experimental observations have shown that polycrystalline NiTi wires, strips and tubes develop inelastic strain via nucleation growth of macroscopic martensitic domains under mechanical loading. These consist almost fully-transformed grains, which result from micro-domains are formed at the grain-size level. Evolution these transformation front propagation is accompanied by complex interactions between work, latent heat, heat transfer, loading rates. could affect performance reliability or controllability material when deployed. Therefore, modeling effort necessary to describe so as improve design application SMA devices. A 3-D thermodynamically consistent thermomechanical model, able phase transition kinetics in shape memory alloys, proposed this work. The model employs a Ginzburg-Landau-type kinetic law resulting notion configurational forces associated with gradient an order parameter (a field variable). As first attempt demonstrate capability 1-D simplification implemented within finite element framework. Kinetics effects production coupling on stress-strain response examined. In particular, roles external rate transfer boundary conditions investigated for displacement-controlled Results obtained good agreement experimental trends.© 2014 ASME