Forerunning mode transition in a continuous waveguide

作     者：Slepyan, Leonid Ayzenberg-Stepanenko, Mark Mishuris, Gennady 

作者机构：Tel Aviv Univ Sch Mech Engn IL-69978 Tel Aviv Israel Shamoon Coll Engn IL-84105 Beer Sheva Israel Aberystwyth Univ Inst Math & Phys Ceredigion SY23 3BZ Wales 

出 版 物：《JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS》 (固体力学与固体物理学杂志)

年 卷 期：2015年第78卷

页      面：32-45页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：FP7 PEOPLE Marie Curie IAPP Grant [284544-PARM2] 

主　　题：Delamination Dynamics Beams and columns Transition waves Numerical algorithms 

摘      要：We have discovered a forerunning mode transition as the periodic wave changing the state of a uniform continuous waveguide. The latter is represented by an elastic beam initially rested on an elastic foundation. Under the action of an incident sinusoidal wave, the separation from the foundation occurs propagating in the form of a transition wave. The critical displacement is the separation criterion. Under these conditions, the steady-state mode exists with the transition wave speed independent of the incident wave amplitude. We show that such a regime exists only in a bounded domain of the incident wave parameters. Outside this domain, for higher amplitudes, the steady-state mode, is replaced by a set of local separation segments periodically emerging at a distance ahead of the main transition point. The crucial feature of this waveguide is that the incident wave group speed is greater than the phase speed. This allows the incident wave to deliver the energy required for the separation. The analytical solution allows us to show in detail how the steady-state mode transforms into the forerunning one. The latter studied numerically turns out to be periodic. As the incident wave amplitude grows the period decreases, while the transition wave speed averaged over the period increases to the group velocity of the wave. As an important part of the analysis, the complete set of solutions is presented for the waves excited by the oscillating or/and moving force acting on the free beam. In particular, an asymptotic solution is evaluated for the resonant wave corresponding to a certain relation between the load s speed and frequency. (C) 2015 Elsevier Ltd. All rights reserved.