## Abstract

To explore a possible mechanism of deep earthquakes, this paper analyzes the unstable propagation of a stress-induced phase transition which is initiated in a homogeneous stress field. This Stephen problem is formulated as an initial-value problem for the phase boundary, and the driving force of the boundary is computed by using the solution of the boundary-value problem for a partially transformed material. The propagation of the phase transition under uniform pressure is numerically simulated. It is shown that (1) under lower pressure, the transition is terminated at a certain size, but it can propagate unstably when an initially transformed region is sufficiently large; and (2) when the pressure attains a critical value, the propagation becomes unstable, and goes in a particular direction depending on the initial shape. These results confirm the possibility of the unstable propagation of phase transition, and provide a theoretical basis for the hypothesis that the phase transition of a mantle material can trigger a deep earthquake.

Original language | English |
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Pages (from-to) | 313-323 |

Number of pages | 11 |

Journal | Mechanics of Materials |

Volume | 21 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1995 Nov |

Externally published | Yes |

## Keywords

- Phase transition
- Stephen problem
- Thermodynamics
- Unstable propagation

## ASJC Scopus subject areas

- General Materials Science
- Instrumentation
- Mechanics of Materials