Costeffective and reliable damage detection is critical for the utilization of composite materials. Interaction of lamb waves with geometric discontinuities. Notes on wave propagation in anisotropic elastic solids. Rayleigh waves have horizontal displacement and the motion of a point in the medium is an ellipse. An analytical approach compared with fem banibrata poddara and victor giurgiutiua adepartment of mechanical engineering, university of south carolina, usa abstract. There has been a clear increase of interest in using lamb waves for identifying structural damage, entailing intensive research and development in this field over the past two decades. Also, in the past decade, there has been increasing interest in the. They are elastic waves whose particle motion lies in the plane that contains the direction of wave propagation and the plane normal the direction perpendicular to the plate.
Krylov and others published geometrical acoustics approximation for rayleigh and lamb waves find, read and cite all the research you need on researchgate. I have just started to look into this subject area which i am completely unfamiliar with. Pdf geometrical acoustics approximation for rayleigh and. Derivation and experimental validation of lamb wave equations. Experimental results are presented for the application of lamb wave techniques to quasi. A partial solution to this complexity is the use of. Here a link to our paper about modeling lamb waves using higher order methods. Apr 05, 20 this animation shows the separation of an a0 and s0 lamb wave, whose group speeds differ slightly. Firestone and ling inaugurated lamb wavebased damage detection in the 19401950s 6, 7, after which lamb waves found. Woodruff school of mechanical engineering, georgia institute of technology, atlanta, georgia 303320405. Structural health monitoring using lamb wave testing polytec. Lamb waves and nearlylongitudinal waves in thick plates. However, for most of the lamb wave modes there is a low attenuation. Lamb waves are guided waves that propagate in thin plate or shell structures.
Lamb waves and nearlylongitudinal waves in thick plates david w. Researcharticle numerical timedomain modeling of lamb wave propagation using elastodynamic finite integration technique husseinrappel,1 aghilyousefikoma,1 jaliljamali,2 andakobahari3. A study of lamb waves in anisotropic plates northwestern. Optimization of lamb wave methods for damage detection in. Rayleigh lamb wave synonyms, rayleigh lamb wave pronunciation, rayleigh lamb wave translation, english dictionary definition of rayleigh lamb wave. Acoustic waves propagating on the surface of solid and hollow elastic cylinders immersed in water were observed and their characteristics shown to be consistent with theory. If you dont want to wait have a look at our ebook offers and start reading immediately. Pdf experimental and theoretical study of rayleighlamb. Simulation and testing of transducers for lamb wave generation. The thickness of the layer where the waves are localized is 12. Scattering characteristics of lamb waves from debondings. When a plate is in contact with a viscous fluid these waves are strongly attenuated. The optimization of lamb and rayleigh wave generation.
The nondestructive testing of materials can be conducted by various techniques. There are two groups of waves, symmetric and antisymmetric as seen in figure, that satisfies the wave equation for this problem. From source to detector sound from an instrument to ear cell phone to cell tower and vice versa em waves water waves a disturbance in the water moves outward. Jacobsa school of civil and environmental engineering, georgia institute of technology, atlanta, georgia 303320355 jianmin qu and jacek jarzynski g. Fundamentals and analysis of lamb waves springerlink. Complications that are encountered in applying lamb waves include the existence of multiple modes and the dispersive character of the modes. Damage in materialsstructures can be detected by analyzing the difference between the phasegroup velocity and the loss of amplitude of lamb waves on damaged and undamaged. Barsauskas ultrasound institute, kaunas university of technology abstract interpretation of the ultrasonic signals measured in guided waves applications usually are more complicated comparing to. Waves that have compressions and rarefactions perpendicular to the direction of propagationperpendicular to the direction of propagation. Typically, lambwave patterns can be observed when there is a highvelocity stiff layer at the top of a nearsurface section. It has been demonstrated that geometrical acoustics approximation for rayleigh waves and for lamb waves of the lowest order, especially flexural waves, is a powerful tool.
Description of lamb waves lamb waves are a form of elastic perturbation that can propagate in a solid plate with free boundaries, first escribed in theory by horace lamb in 1917 16d 18. Benoit gerardin, jerome laurent, claire prada and alexandre aubry, negative reflection of lamb waves at a free edge. Timefrequency representation of lamb waves using the reassigned spectrogram marc niethammer, laurence j. Therein lies my problem as it seems to be one of the rarest books out there. By matching theoretical multimodal lamb wave dispersion curves with experimental ones, shear wave velocity vs, poissons ratio, and thickness of the tested plate structure can be evaluated. Rayleigh waves occur on the earths surface during earthquakes. Scattering characteristics of lamb waves from debondings at structural features in composite laminates chingtai nga school of civil, environmental and mining engineering, the university of. The calculation includes stoneley waves along a solidsolid interface of two bonded halfspaces, rayleigh lamb type waves in a layered halfspace, and guided waves in a general multilayered plate. Timefrequency representation of lamb waves using the.
Lamb waves lamb, 1917 are guided dispersive waves propagating in free plate structures. Ultrasonic waves used to check the surface layer of various device components and specimens are another example of rayleigh waves. Lamb wave inspection of large structures using permanently attached transducers by paul david wilcox a thesis submitted to the university of london for the degree of doctor of philosophy department of mechanical engineering imperial college of science, technology and medicine london sw7 2bx march 1998. Lamb waves with particle displacement in both the x and ydirection actually represents a group. If you are a society or association member and require assistance with obtaining online access instructions please contact our journal customer services team. This animation shows the separation of an a0 and s0 lamb wave, whose group speeds differ slightly. Types of mechanical waves waves that have compressions and rarefactions parallelwaves that have compressions and rarefactions parallel to the direction of wave propagation are longitudinal.
These waves were excited by an 11sec pulse, projected onto the cylindrical surface at an excitation angle given by sin 1 c o c s, where c o is the velocity of sound in water and c s is the velocity of the surface wave. This paper presents part of an experimental and analytical survey of candidate methods for insitu damage detection of composite materials. Rayleigh and lamb waves basic principles worden 2008. Lamb waves are formed by interference of multiple reflections and mode conversion of longitudinal waves p waves and shear waves s waves at the free surfaces of the plate viktorov, 1967. I have been told to get myself a copy of rayleigh and lamb waves.
Traveling waves waves propagate from one place to another. Numerical timedomain modeling of lamb wave propagation using. Timeefficient simulation of surfaceexcited guided lamb wave. Rayleigh waves have a speed slightly less than shear waves by a factor dependent on the elastic constants of the material. Theory lamb waves are twodimensional vibrations propagating in plates with free boundary conditions. Rayleigh waves involve interaction between p and 5 waves at a free surface. They are elastic waves whose particle motion lies in the plane that contains the direction of wave propagation. A free surface requires the tractions to vanish at x 3 0.
Rayleighlamb wave article about rayleighlamb wave by the. Timefrequency representations of lamb waves marc niethammer and laurence j. Physical theory and applications ultrasonic technology on free shipping on qualified orders. Guided lamb waves based structural health monitoring. Sometimes they are referred to as free or normal modes, because. Rayleigh and lamb waves transport in random waveguides. Rayleighlamb wave definition of rayleighlamb wave by the.
Lamb waves can be used for nondestructive testing of aluminum aircraft panels, composite panels, and other plateshaped objects. For additional information on lamb waves, see the wave mode page in the ultrasonic inspection section. Lamb waves are ultrasonic guided waves that propagate between two parallel free surfaces and their use for damage detection has been widely explored and demonstrated. Tunable focusing and mimicking phase conjugation, the journal of the acoustical society of america, 140, 1, 591, 2016. Your print orders will be fulfilled, even in these challenging times. Interaction of lamb wave modes with weak material nonlinearity.
The main part of the article presents measurement results obtained with this. Numerical simulation of lamb wave scattering in semi. For signal processing applications, lamb waves are. Modelling of attenuation of lamb waves using rayleigh damping. One of the main problems in lamb wave testing is the dispersive nature of lamb waves. Experimental and theoretical study of rayleighlamb waves in a plate containing a surfacebreaking crack article pdf available in research in nondestructive evaluation 14. Traveling perpendicular to the plate thickness, being guided. Lamb waves and dispersion curves in plates and its. Typically, lambwave patterns can be observed when there is a high velocity stiff layer at the top of your section. Lamb waves are reflected in material properties and geometric discontinuities, such as damages.
Rayleigh and lamb waves physical theory and applications. Lecture 11 chapter 16 waves i university of virginia. When the excitation of a particular mode is made by a broadband pulse. The guided lamb wave is widely acknowledged as one of the most encouraging tools for quantitative identification of damage in composite structures, and relevant research has been conducted intensively since the 1980s. N2 this paper is concerned with the lamb wave spectra for layered orthotropic elastic media. Rayleighlamb wave from eric weissteins world of physics. Determination of lamb wave dispersion curves by means of. Rayleigh waves are distinct from other types of surface or guided acoustic waves such as love waves or lamb waves, both being types of guided waves supported by a layer, or longitudinal and shear waves, that travel in the bulk. A type of seismic surface wave that moves with a rolling motion, causing rock particles to vibrate in directions both perpendicular and parallel to the. A comprehensive solution to lamb waves was completed by mindlin in 1950, followed by considerable detail provided by gazis in 1958 4 and viktorov in 1967 5 who also first evaluated the dispersive properties of lamb waves. This paper investigates the interaction of different shear and rayleighlambguided waves in plates with a discontinuity such as a. For many applications, lamb waves are of primary concern because they are able to give the best indication of wave propagation from a source whose distance from the sensor is larger than the thickness of the material. Viktorov and a great selection of related books, art and collectibles available now at.
Their displacements may be symmetric or antisymmetric with respect to the middle plane of the plate. Guided lamb waves for identification of damage in composite. Attenuation of lamb waves, both fundamental symmetric and antisymmetric modes, propagating through viscoelastic media crossply glassepoxy laminate was modelled using the finite element method. Pdf solutions of rayleigh waves and lamb waves generated. In such instances, some parts of the dispersion curves may exhibit features that resemble lambwave plate wave patterns and not rayleigh wave, free rayleigh waves can only. In such instances some parts of the dispersion curves may exhibit features that resemble lamb wave plate wave patterns and not rayleigh wave, free rayleigh waves. Viktorov, 9781489956835, available at book depository with free delivery worldwide.