We analyse the kinetics of the transition between two variants of martensite during biaxial dead loading. The volume fraction of one martensite variant versus the applied loads exhibits an unusual hysteresis, characterized by a sensitive dependence on the amplitude of the loads and a dissipationless response at small amplitude. Observation of the microscopic volume fraction at the level of a few bands of martensite reveals that the main mechanism by which one variant grows at the expense of another is a tip-splitting event; the tips of martensite needles present in the specimen suddenly split. This leads us to adopt a form of the energy in which many little wiggles are superposed on a slowly varying function that accounts for the loading device, elastic and interfacia] energies. We analyse the resulting microscopic kinetic law by deriving from it a macroscopic kinetic equation that governs the average response. This law inherits the phenomenon of ‘getting stuck in local minima of the energy’. It leads to good qualitative (and fair quantitative) agreement with observation over a very wide range of different kinds of experiment.
|Original language||English (US)|
|Number of pages||41|
|Journal||Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties|
|State||Published - Feb 1996|
Bibliographical noteFunding Information:
Rohan Abeyaratne would like to thank the Department of Aerospace Engineering and Mechanics at the University of Minnesota for the warm and stimulating environment that it provided him during the Fall of 1992. The authors thank the Office of Naval Research (N00014-93-1-0240 and N00014-91-5-4034), the Air Force Office of Scientific Research (AFOSR-91-0301), the National Science Foundation (CMS-95-03633 and DMS-9111572-02) and the Army Research Office (DAAL03-92-G-0003) for supporting this work.