离散网格中的弹性波动(Ⅱ)——几种有限元离散模型的对比分析  

ELASTIC WAVE MOTION IN DISCRETE GRIDS (Ⅱ )——Comparison of common finite clement models

作　　者：刘晶波[1] 廖振鹏[1] 

机构地区：[1]国家地震局工程力学研究所

出　　处：《地震工程与工程振动》1989年第2期1-11,共11页Earthquake Engineering and Engineering Dynamics

基　　金：地震科学联合基金

摘　　要：本文系统地对比分析了集中质量、一致质量和混合质量有限元一维离散模型中弹性波的频散、截止频率和寄生振荡性质。结果表明,从实用观点看来集中质量模型较之一致质量模型可取。为了获得连续介质中波动过程更逼真的模拟,可以采用混合质量法。本文讨论了混合质量法中质量分配系数的优化选取及离散化准则。最后分析了弹性波穿过离散网格间断面的性质并提出了减小由此而引起的误差的方法。Dispersion, cut off frequency and parasitic oscillation arc compared and analyzed systematically for Lumped-mass, Consistent-mass and Hybrid-mass one-dimensional finite element model. The Lumped-mass model is preferable to the Consistent-mass model from a practical view point, and the Hybrid-mass model would provide a more accurate imitation of wave propagation in continuum. The optimum choice of mass allocation coefficient are discussed for Hybrid-mass model and the discretization criterion are provided to ensure a certain accuracy of the computation. Characteristics of wave propagation passing through discontinuities of the discrete grids are finally studied, and the corresponding measures are presented for use to eliminate and reduce the error caused by the discontinuity.

关 键 词：离散网络 弹性波 有限元 离散模型 

分 类 号：TB123[理学—工程力学]