A cavitation and dynamic void growth model for a general class of strain-softening amorphous materials. (August 2020)

• Record Type: Journal Article
• Authors: Tang, X.C.; Nguyen, Thao; Yao, X.H.; Wilkerson, Justin W.
• Is Part Of: Journal of the mechanics and physics of solids. Volume 141(2020)
• Publication Date: 2020-08
• Subjects: Bulk metallic glass -- Cavitation -- Damage -- Free volume theory -- Shock -- Spall; Mechanics, Applied -- Periodicals; Solids -- Periodicals; Mechanics -- Periodicals; Mécanique appliquée -- Périodiques; Solides -- Périodiques; Mechanics, Applied; Solids; Periodicals; 531.05
• DOI: 10.1016/j.jmps.2020.104023
• Languages: English
• ISSNs: 0022-5096

Abstract

Abstract: In this work, we derive a homogenized framework for cavitation and dynamic void growth in a general class of strain-softening materials with particular emphasis on amorphous materials. Analytic solutions are derived by considering an assemblage of spherical shells subject to dynamic hydrostatic tensile pressure. The isochoric response of the matrix material is captured by a free volume theory based amorphous viscoplasticity model. The framework accounts for the coupled rate-dependent, strain-softening behavior typically exhibited in amorphous materials. Validation of the homogenized theory is carried out against numerous direct numerical simulations with excellent agreement. We find that a reduction in cavitation strength and significant acceleration of dynamic void growth rates is induced as a consequence of strain-softening in the amorphous matrix material. Lastly, the model is utilized to interpret some non-intuitive experimental observations of amorphous materials subject to shock compression and subsequent spall failure.