IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-28 DOI: 10.1016/j.wavemoti.2024.103432

{"title":"Constitutive modelling and wave propagation through a class of anisotropic elastic metamaterials with local rotation","authors":"","doi":"10.1016/j.wavemoti.2024.103432","DOIUrl":"10.1016/j.wavemoti.2024.103432","url":null,"abstract":"<div><div>Elastic metamaterials are typically periodic materials possessing unit cells endowed with engineered architecture much smaller than the typical phenomenological length scale. The development of continuum models capable of accurately representing the effects of this aforementioned architecture is extremely challenging, and hence a sparsely developed area. This paper develops a novel 2-D continuum model capable of capturing the dynamic behaviour of a class of anisotropic elastic metamaterials with local rotational elements in the long wavelength limit. A constitutive relation incorporating these local rotational effects is proposed, and ratified using a representative discrete model using linear Hookean springs and identical rigid disks. The new continuum model is used to generate a dispersion relation for harmonic plane waves propagating in an arbitrary direction, which is subsequently compared to the dispersion behaviour of the original discrete model. The general behaviour of this continuum when subjected to 2-D planar harmonic wave propagation in the anisotropic medium is then analysed, with specific attention given to the effect of material anisotropy and wave propagation direction. This work is the first of its kind to create a new continuum model of a class of anisotropic elastic metamaterials with local rotational effects.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572515","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

On peridynamic acoustics 关于周动声学

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-28 DOI: 10.1016/j.wavemoti.2024.103429

引用次数: 0

Accurate computation of scattering poles of acoustic obstacles with impedance boundary conditions 带阻抗边界条件的声学障碍物散射极点的精确计算

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-24 DOI: 10.1016/j.wavemoti.2024.103425

引用次数: 0

Derivation of weakly interacting lumps for the (2+1)-dimensional Yu–Toda–Sasa–Fukuyama equation via degeneracy of lump chains 通过块链的退化性推导 (2+1)-dimensional Yu-Toda-Sasa-Fukuyama 公式的弱相互作用块体

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-22 DOI: 10.1016/j.wavemoti.2024.103423

{"title":"Derivation of weakly interacting lumps for the (2+1)-dimensional Yu–Toda–Sasa–Fukuyama equation via degeneracy of lump chains","authors":"","doi":"10.1016/j.wavemoti.2024.103423","DOIUrl":"10.1016/j.wavemoti.2024.103423","url":null,"abstract":"<div><div>This paper introduces two distinct pathways for degenerating normally interacting lump chains into weakly interacting lump waves for Yu–Toda–Sasa–Fukuyama equation, which will enrich the correlation between lump chains and weakly interacting lump waves. The first pathway involves letting the periods of <span><math><mi>M</mi></math></span> similarly-velocity lump chains approach infinity directly. The second pathway first transforms <span><math><mi>M</mi></math></span> normally interacting lump chains into weakly interacting lump chains with similar dynamic behaviors. Then, by allowing their periods to approach infinity, <span><math><mfrac><mrow><mi>M</mi><mfenced><mrow><mi>M</mi><mo>+</mo><mn>1</mn></mrow></mfenced></mrow><mrow><mn>2</mn></mrow></mfrac></math></span> weakly interacting lump waves are produced. Distance between weakly interacting lump chains in this equation is proportional to <span><math><mrow><mo>ln</mo><mo>|</mo><mi>t</mi><mo>|</mo></mrow></math></span>, while between weakly interacting lump waves is proportional to <span><math><mroot><mrow><mo>|</mo><mi>t</mi><mo>|</mo></mrow><mrow><mn>3</mn></mrow></mroot></math></span>. These findings will contribute valuable theoretical insights to the study of wave theory, ocean science and related disciplines.</div></div>","PeriodicalId":49367,"journal":{"name":"Wave Motion","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552650","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

Compactons in a class of doubly sublinear Gardner equations 一类双次线性加德纳方程中的紧凑子

IF 2.1 3区物理与天体物理

Wave Motion Pub Date : 2024-10-22 DOI: 10.1016/j.wavemoti.2024.103427

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

引用次数: 0

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

{"title":"Test of the relation between temporal and spatial Q by Knopoff et al.","authors":"","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":null,"pages":null},"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

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

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

{"title":"On the lifespan of nonzero background solutions to a class of focusing nonlinear Schrödinger equations","authors":"","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":null,"pages":null},"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

引用次数: 0

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