Wave propagation in two-dimensional hierarchical honeycomb structures with two- order hierarchy is investigated by using the symplectic algorithm. By applying the variational prin- ciple to the dual variables, the wav...Wave propagation in two-dimensional hierarchical honeycomb structures with two- order hierarchy is investigated by using the symplectic algorithm. By applying the variational prin- ciple to the dual variables, the wave propagation problem is transformed into a two-dimensional symplectie eigenvalue problem. The band gaps and spatial filtering phenomena are examined to find the stop bands and directional stop bands. Special attention is directed to the effects of the relative density and the length ratio on the band gaps and phase constant surfaces. This work provides new opportunities for designing hierarchical honeycomb structures in sound insulation applications.展开更多
Wave propagation in infinitely long hollow sandwich cylinders with prismatic cores is analyzed by the extended Wittriek-Williams （W-W） algorithm and the precise integration method （PIM）. The effective elastic cons...Wave propagation in infinitely long hollow sandwich cylinders with prismatic cores is analyzed by the extended Wittriek-Williams （W-W） algorithm and the precise integration method （PIM）. The effective elastic constants of prismatic cellular materials are obtained by the homogenization method. By applying the variational principle and introducing the dual variables the canonical equations of Hamiltonian system are constructed. Thereafter, the wave propagation problem is converted to an eigenvalue problem. In numerical examples, the effects of the prismatic cellular topology, the relative density, and the boundary conditions on dispersion relations, respectively, are investigated.展开更多
基金Project supported by the National Basic Research Program of China(No.2011CB610300)the National Natural Science Foundation of China(Nos.11172239 and 11372252)+3 种基金the Doctoral Program Foundation of Education Ministry of China(No.20126102110023)the Fundamental Research Funds for the Central Universities(Nos.310201401JCQ01001 and 3102015ZY036)China Postdoctoral Science Foundation(No.2013M540724)Shaanxi postdoctoral research projects
文摘Wave propagation in two-dimensional hierarchical honeycomb structures with two- order hierarchy is investigated by using the symplectic algorithm. By applying the variational prin- ciple to the dual variables, the wave propagation problem is transformed into a two-dimensional symplectie eigenvalue problem. The band gaps and spatial filtering phenomena are examined to find the stop bands and directional stop bands. Special attention is directed to the effects of the relative density and the length ratio on the band gaps and phase constant surfaces. This work provides new opportunities for designing hierarchical honeycomb structures in sound insulation applications.
基金supported by the National Basic Research Program of China(No.2011CB610300)the 111 project(No.B07050)+4 种基金the National Natural Science Foundation of China(Nos.11172239 and 11372252)the Doctoral Program Foundation of Education Ministry of China(No.20126102110023)the Fundamental Research Funds for the Central Universities(310201401JCQ01001)China Postdoctoral Science Foundation(2013M540724)Shaanxi postdoctoral research projects
文摘Wave propagation in infinitely long hollow sandwich cylinders with prismatic cores is analyzed by the extended Wittriek-Williams （W-W） algorithm and the precise integration method （PIM）. The effective elastic constants of prismatic cellular materials are obtained by the homogenization method. By applying the variational principle and introducing the dual variables the canonical equations of Hamiltonian system are constructed. Thereafter, the wave propagation problem is converted to an eigenvalue problem. In numerical examples, the effects of the prismatic cellular topology, the relative density, and the boundary conditions on dispersion relations, respectively, are investigated.
