基于半解析有限元的各向异性管道纵向导波传播特性分析OA

Based on the semi-analytical finite element method,the characteristic equation for guided waves in orthotropic materials is derived,and the characteristic equation is solved numerically.Firstly,to determine the correctness and applicability of the method,the dispersion curves of guided waves in an isotropic hollow cylinder are calculated using Disperse a wave dispersion software package.The results obtained from the semi-analytical finite element method are compared with those from Disperse,and the two set of results are found to be in complete agreement.Then,the influence of the number of pipeline section elements on the calculation of the guided wave dispersion curves is discussed,and the reasons for this influence are analyzed.Finally,the phase velocity dispersion curves of guided waves in a composite material pipeline made of orthorhombic crystals are determined.The effects of the material layup direction and the radius-to-thickness ratio on the dispersion curves are analyzed.Both factors exhibit a systematic influence on the dispersion characteristics of the low-frequency modes.When the radius-to-thickness ratio is sufficiently large,the dispersion curves for pipes and plates of the same material and thickness tend to converge.