The Maxwell stability criterion in pseudo-energy models of kink banding

Kink banding, common to many structures in nature and engineering, has seve ral distinctive features-notably highly nonlinear snap-back instability lea ding to localization and sequential lock-up. The proposed friction model, a lthough simplified, introduces these defining characteristics without obscu ring them by including other effects of lesser immediate significance. In t he absence of small imperfections or disturbances, linearized theory sugges ts that in its pre-kinked configuration the system never goes unstable. How ever, under sufficient applied end-displacement it is in a state of extreme metastability, such that micro-disturbances would trigger a non-linear res ponse. This is overcome when an energy approach based on a global rather th an a local stability criterion is used. When applied to imperfect systems w ith small initial misalignments, the critical displacement thus defined sho ws little of the sensitivity expected from other stability criteria, and pr ovides a lower bound on the expected critical displacement and associated l oad. (C) 2000 Elsevier Science Ltd. All rights reserved.