Wave Motion最新文献_第10页

Test of the relation between temporal and spatial Q by Knopoff et al. Knopoff 等人对时间和空间 Q 之间关系的测试。

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-22 DOI: 10.1016/j.wavemoti.2024.103424

José M. Carcione , Jing Ba

{"title":"Test of the relation between temporal and spatial Q by Knopoff et al.","authors":"José M. Carcione , Jing Ba","doi":"10.1016/j.wavemoti.2024.103424","DOIUrl":"10.1016/j.wavemoti.2024.103424","url":null,"abstract":"<div><div>The quality factor is a dimensionless measure of the energy loss per cycle of wave modes in an attenuation medium. Accurate measurement is important in various fields, from seismological studies to detect zones of partial melting to the geophysics of reservoirs to study rock properties such as porosity, fluid properties and saturation and permeability. In seismology, the quality factors measured for normal (standing) modes and propagating waves differ, as well those of equivalent experiments based on resonant rods and ultrasonic pulses performed in the laboratory. These measurements result in temporal and spatial quality factors respectively. A relationship between these two different quality factors and between the corresponding attenuation factors was proposed by Knopoff et al. sixty years ago. The conversion factor is basically the ratio between the phase velocity and the group velocity, while for the attenuation factor is the group velocity. We test these relations, which hold for low-loss solids, for body waves, using a Kelvin–Voigt rheology and a constant <span><math><mi>Q</mi></math></span> model, which provide explicit expressions of the temporal and spatial quality factors and velocities involved in these relations. The proposed theory provides the basis for a complete characterization of temporal and spatial quality factors and velocity dispersion based on arbitrary stress–strain relationships.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"132 ","pages":"Article 103424"},"PeriodicalIF":2.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The dynamic behaviors between double-hump solitons in birefringent fibers 双折射光纤中双驼峰孤子之间的动态行为

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-22 DOI: 10.1016/j.wavemoti.2024.103426

Liu Yang, Ben Gao

引用次数: 0

Localized solutions of the wave equation 波方程的局部解

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-19 DOI: 10.1016/j.wavemoti.2024.103418

John Lekner

引用次数: 0

Longitudinal wave propagation in a practical metamaterial lattice 实用超材料晶格中的纵波传播

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-19 DOI: 10.1016/j.wavemoti.2024.103431

Ting Wang , Huachang Cui , Jingyu Zhang , Hanbei Guo , Meixia Chen

{"title":"Longitudinal wave propagation in a practical metamaterial lattice","authors":"Ting Wang , Huachang Cui , Jingyu Zhang , Hanbei Guo , Meixia Chen","doi":"10.1016/j.wavemoti.2024.103431","DOIUrl":"10.1016/j.wavemoti.2024.103431","url":null,"abstract":"<div><div>A practical metamaterial lattice is constructed by integrating curved beams, four-link mechanisms, and cantilever beams with lumped masses. It can generate two complete low-frequency bandgaps due to the lateral local resonance, inertia mass, and the main chain. The effective mass density and stiffness are obtained using different effective models, which show negative within the bandgaps. The analysis of the energy distribution and the space wave attenuation reveals that the metamaterial can attenuate the elastic waves in an exponential form within the bandgaps along the lattice. The finite element model is established to show the dynamic behaviour of the elastic wave propagation in the frequency domain and transient domain. Both results show that waves can be efficiently blocked within the bandgaps, while outside the bandgaps, waves can propagate without any attenuation. Finally, the experimental model of practical metamaterial is constructed, and the test piece is excited by a force hammer. Experimental results verify that the practical metamaterial can efficiently suppress the vibration within the bandgap frequency and validate the accuracy of the theoretical prediction.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"132 ","pages":"Article 103431"},"PeriodicalIF":2.1,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A single layer representation of the scattered field for multiple scattering problems 多散射问题的散射场单层表示法

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-16 DOI: 10.1016/j.wavemoti.2024.103422

Didier Felbacq, Anthony Gourdin, Emmanuel Rousseau

引用次数: 0

On the lifespan of nonzero background solutions to a class of focusing nonlinear Schrödinger equations 论一类聚焦非线性薛定谔方程非零背景解的寿命

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-11 DOI: 10.1016/j.wavemoti.2024.103419

Dirk Hennig , Nikos I. Karachalios , Dionyssios Mantzavinos , Dimitrios Mitsotakis

{"title":"On the lifespan of nonzero background solutions to a class of focusing nonlinear Schrödinger equations","authors":"Dirk Hennig , Nikos I. Karachalios , Dionyssios Mantzavinos , Dimitrios Mitsotakis","doi":"10.1016/j.wavemoti.2024.103419","DOIUrl":"10.1016/j.wavemoti.2024.103419","url":null,"abstract":"<div><div>The global solvability in time and the potential for blow-up of solutions to non-integrable focusing nonlinear Schrödinger equations with nonzero boundary conditions at infinity present challenges that are less explored and understood compared to the case of zero boundary conditions. In this work, we address these questions by establishing estimates on the lifespan of solutions to non-integrable equations involving a general class of nonlinearities. These estimates depend on the size of the initial data, the growth of the nonlinearity, and relevant quantities associated with the amplitude of the background. The estimates provide quantified upper bounds for the minimum guaranteed lifespan of solutions. Qualitatively, for small initial data and background, these upper bounds suggest long survival times consistent with global existence of solutions. On the other hand, for larger initial data and background, the estimates indicate the potential for the intriguing phenomenon of instantaneous collapse in finite time. These qualitative theoretical results are illustrated via numerical simulations. Furthermore, importantly, the numerical findings motivate the proof of improved theoretical upper bounds that provide excellent quantitative agreement with the order of the numerically identified lifespan of solutions.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"132 ","pages":"Article 103419"},"PeriodicalIF":2.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generalised eigenfunction expansion and singularity expansion methods for canonical time-domain wave scattering problems 典型时域波散射问题的广义特征函数展开和奇异性展开方法

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-11 DOI: 10.1016/j.wavemoti.2024.103421

Ben Wilks , Michael H. Meylan , Fabien Montiel , Sarah Wakes

引用次数: 0

Natural frequencies of a Timoshenko beam with cracks 有裂缝的季莫申科梁的自然频率

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-06 DOI: 10.1016/j.wavemoti.2024.103420

E.I. Shifrin, I.M. Lebedev

引用次数: 0

Rogue waves on the periodic background for a higher-order nonlinear Schrödinger–Maxwell–Bloch system 高阶非线性薛定谔-麦克斯韦-布洛赫系统的周期性背景上的游荡波

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-09-29 DOI: 10.1016/j.wavemoti.2024.103417

Jian Chang, Zhaqilao

引用次数: 0

On the viscoelastic-electromagnetic-gravitational analogy 关于粘弹性-电磁-引力类比

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-09-19 DOI: 10.1016/j.wavemoti.2024.103411

José M. Carcione , Jing Ba

{"title":"On the viscoelastic-electromagnetic-gravitational analogy","authors":"José M. Carcione , Jing Ba","doi":"10.1016/j.wavemoti.2024.103411","DOIUrl":"10.1016/j.wavemoti.2024.103411","url":null,"abstract":"<div><div>The analogy between electromagnetism and gravitation was achieved by linearizing the tensorial gravitational equations of general relativity and converting them into a vector form corresponding to Maxwell’s electromagnetic equations. On this basis, we use the equivalence with viscoelasticity and propose a theory of gravitational waves. We add a damping term to the differential equations, which is equivalent to Ohm’s law in electromagnetism and Maxwell’s viscosity in viscoelasticity, to describe the attenuation of the waves. The differential equations in viscoelasticity are those of cross-plane shear waves, commonly referred to as SH waves. A plane-wave analysis gives the phase velocity, the energy velocity, the quality factor and the attenuation factor of the field as well as the energy balance. To obtain these properties, we use the analogy with viscoelasticity; the properties of electromagnetic and gravitational waves are similar to those of shear waves. The presence of attenuation means that the transient field is generally a composition of inhomogeneous (non-uniform) plane waves, where the propagation and attenuation vectors do not point in the same direction and the phase velocity vector and the energy flux (energy velocity) are not collinear. The polarization of cross-plane field is linear and perpendicular to the propagation-attenuation plane, while the polarization of the field within the plane is elliptical. Transient wave fields in the space–time domain are analyzed with the Green function (in homogeneous media) and with a grid method (in heterogeneous media) based on the Fourier pseudospectral method for calculating the spatial derivatives and a Runge–Kutta scheme of order 4 for the time stepping. In the examples, wave propagation at the Sun–Earth and Earth–Moon distances using quadrupole sources is considered in comparison to viscoelastic waves. The Green and grid solutions are compared to test the latter algorithm. Finally, an example of propagation in heterogeneous media is presented.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":"131 ","pages":"Article 103411"},"PeriodicalIF":2.1,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0