Implications of the similarity principle relating creep and attenuation in finely grained solids

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:521-22

Article; Proceedings Paper

Morris, S. J. S.¹  Jackson, Ian² 

[1] Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA

[2] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia

关键词: Grain boundary sliding;    Mechanical spectroscopy;    Grain boundaries;    Dimensional analysis;    Similitude;   

DOI  :  10.1016/j.msea.2008.09.157

来源: Elsevier

【 摘 要 】

The Raj-Ashby model of diffusionally accommodated grain-boundary sliding implies the existence of similitude in the mechanical loss spectrum of finely grained solids: the quality factor Q of a shear wave propagating with angular frequency omega is related to the viscosity eta for steady-state Coble creep and the (unrelaxed) rigidity mu through a dimensionless relation of the form Q = F(omega eta/mu). Using existing measurements of eta and Q obtained respectively from uniaxial creep tests, and forced torsional oscillation tests, we test that prediction. Though the similarity principle appears to hold, definitive proof will require further measurements of Q and eta over a larger range of grain sizes. With that proviso, we conclude that the Raj-Ashby model includes the basic physical mechanisms acting in the experiments underlying two existing data sets on attenuation in the geological material olivine. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

Free