High-Directional Wave Propagation in Periodic Gain/Loss Modulated Materials

Trapping and Steering on Lattice Strings: Virtual Slow Waves, Directional and Non-propagating Excitations

Using a lattice string model, a number of peculiar excitation situations related to non-propagating excitations and non-radiating sources are demonstrated. External fields can be used to trap excitations locally but also lead to the ability to steer such excitations dynamically as long as the steering is slower than the field's wave propagation. I present explicit constructions of a number of examples, including temporally limited non-propagating excitations, directional excitation and virtually slowed propagation. Using these dynamical lattice constructions I demonstrate that neither persiste…

A Simple Multi-Directional Absorbing Layer Method to Simulate Elastic Wave Propagation in Unbounded Domains

The numerical analysis of elastic wave propagation in unbounded media may be difficult due to spurious waves reflected at the model artificial boundaries. This point is critical for the analysis of wave propagation in heterogeneous or layered solids. Various techniques such as Absorbing Boundary Conditions, infinite elements or Absorbing Boundary Layers (e.g. Perfectly Matched Layers) lead to an important reduction of such spurious reflections. In this paper, a simple absorbing layer method is proposed: it is based on a Rayleigh/Caughey damping formulation which is often already available in e…

周期材料方向性的分析

Analysis of the directionality on periodic materials

本文针对周期材料的方向性描述问题，提出一种基于动态行为的各向异性度量方法，以 Bloch 频散曲面为输入输出编码体方向性的曲线或曲面，并在弹性动力学中验证其有效性。