EP0219421A1 - Sonar dome - Google Patents
Sonar dome Download PDFInfo
- Publication number
- EP0219421A1 EP0219421A1 EP86402194A EP86402194A EP0219421A1 EP 0219421 A1 EP0219421 A1 EP 0219421A1 EP 86402194 A EP86402194 A EP 86402194A EP 86402194 A EP86402194 A EP 86402194A EP 0219421 A1 EP0219421 A1 EP 0219421A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- resin
- dome
- layers
- impregnated
- sonar
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/004—Mounting transducers, e.g. provided with mechanical moving or orienting device
- G10K11/006—Transducer mounting in underwater equipment, e.g. sonobuoys
Definitions
- the invention relates to a dome for sonar, that is to say a dome for protecting the antennas of a hull sonar or of a towed sonar.
- Sonar system antennas must be mechanically protected against shock, flow noise, corrosion, etc. This protection is provided by a hollow or solid dome which must therefore be made of a very mechanically resistant and transparent material acoustically, at least in the frequency band used. Acoustically transparent materials are those whose density is close to that of water and where the speed of propagation of sound waves is substantially equal to that in water. The transmission coefficient is then close to 1.
- thermoset polyurethane thermoset polyurethane
- a dome in the form of a hull, in a composite material consisting of webs woven from glass fibers, impregnated with a resin. polyester.
- This material has a modulus of elasticity (defined by the ratio between the applied stress and the resulting deformation) of such value that it leads to relatively large shell thicknesses, resulting in poor transmission.
- the object of the invention is to produce a dome having a low weight and good acoustic transmission, while being easy to construct.
- the object of the invention is a dome of composite material of the sandwich type comprising a layer of glass fibers and two layers of carbon fibers, impregnated with a resin, combined so as to avoid the drawbacks of domes of known types.
- a sonar dome is characterized in that it comprises a wall comprising a central layer formed by several layers woven in glass fibers, impregnated with a resin, and by two peripheral layers, located on the right and 'other of the central layer, and formed of several layers woven of carbon fibers, impregnated with a resin.
- the dome has a hull shape whose wall 3 is made in one piece, bolted on its periphery to the hull 1 of a ship.
- a sonar antenna, 2, fixed to the hull 1 of the ship, is located in the hollow of the dome and bathes in water 4, retained by the dome.
- Figure 2 shows, by enlarging it, a section of the wall 3. It is composed of a sandwich formed of three layers: - two peripheral layers 6 and 8, consisting of three woven plies, called "folds", formed of carbon fibers; - A central layer 7 consisting of eight plies of glass fibers.
- thermosetting epoxy resin The three layers 6, 7, and 8 are impregnated with a thermosetting epoxy resin. During the hardening of the resin, these three layers are strongly pressed together and polymerized, in an oven, with a rise in temperature and pressure adapted to the resin used and the choice of which is within the reach of the man of the art.
- the central layer has a thickness of 5 mm.
- the two peripheral layers have an identical thickness: 1.5 mm, in order to obtain a stability of the material from a mechanical and thermal point of view, that is to say avoid deformations due to mechanical or thermal stresses.
- the dome according to the invention has good acoustic transmission and great resistance to bending thanks to the carbon fibers which are located far from the neutral axis.
- FIG. 3 represents an example of weaving one of the plies of carbon fibers constituting the layers 6 and 8. Wicks of carbon fibers are crossed with an identical pitch, for example 3, in the transverse direction and a pitch of 3 in the longitudinal direction due to the stiffness of the carbon fibers.
- the weaving of the plies of glass fibers, which is not shown, is carried out with a ratio of 1/1.
- the wall thus produced has a tensile elasticity module of 28 Gigapascals with an acoustic transmission coefficient of 98%. If the dome had been made entirely of glass fibers and polyester resin, the thickness necessary to obtain the same resistance would have been 16 mm and would have given a transmission coefficient close to 92%. In addition, the weight gain is in a ratio 2.
- the invention is not limited to this exemplary embodiment. It is within the reach of those skilled in the art to use a type of resin other than epoxy resins, for example a thermoplastic resin.
- a resin particularly suitable for carbon fibers can be used in the two peripheral layers and another resin, particularly suitable for glass fibers, can be used for the central layer.
- the wall of the dome according to the invention may comprise additional layers of materials having good acoustic transparency, for example an outer layer of aramid fibers impregnated with epoxy resin, to obtain a particularly high impact resistance.
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- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Laminated Bodies (AREA)
- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Abstract
Un dôme pour sonar, selon l'invention, comporte une paroi (3) comportant une couche centrale (7) formée de plusieurs nappes tissées en fibres de verre, imprégnées d'une résine, et de deux couches périphériques (6, 8), situées de part et d'autre de la couche centrale (7), et formées de plusieurs nappes tissées en fibres de carbone, imprégnées d'une résine.A dome for sonar, according to the invention, comprises a wall (3) comprising a central layer (7) formed of several layers woven from glass fibers, impregnated with a resin, and two peripheral layers (6, 8), located on either side of the central layer (7), and formed of several layers woven of carbon fibers, impregnated with a resin.
Application aux sonars. 
Description
L'invention concerne un dôme pour sonar, c'est-à-dire un dôme pour protéger les antennes d'un sonar de coque ou d'un sonar remorqué.The invention relates to a dome for sonar, that is to say a dome for protecting the antennas of a hull sonar or of a towed sonar.
Les antennes des systèmes sonar doivent être protégées mécaniquement contre les chocs, les bruits d'écoulement, la corrosion, etc... Cette protection est assurée par un dôme creux ou massif qui doit donc être constitué d'un matériau très résistant mécaniquement et transparent acoustiquement, au moins dans la bande des fréquences utilisées. Les matériaux transparents acoustiquement sont ceux dont la masse volumique est proche de celle de l'eau et où la vitesse de propagation des ondes sonores est sensiblement égale à celle dans l'eau. Le coefficient de transmission est alors proche de 1.Sonar system antennas must be mechanically protected against shock, flow noise, corrosion, etc. This protection is provided by a hollow or solid dome which must therefore be made of a very mechanically resistant and transparent material acoustically, at least in the frequency band used. Acoustically transparent materials are those whose density is close to that of water and where the speed of propagation of sound waves is substantially equal to that in water. The transmission coefficient is then close to 1.
Il est connu, notamment par la demande de brevet français n° 2 069 875, déposée par la Demanderesse, de réaliser des dômes massifs en polyuréthane thermodurci. Ce matériau étant mou, il oblige à réaliser des dômes massifs qui conviennent mal lorsqu'il s'agit d'enrober des antennes de forme ellipsoïdale ou sphérique car alors ces antennes ne sont plus accessibles. De plus, au voisinage de 0° Celsius, le coefficient de transmission acoustique de ce matériau devient mauvais. Ce phénomène est gênant car il faut parfois plusieurs heures pour que la masse du matériau reprenne la température de l'eau. Pour la protection d'antennes dont les transducteurs sont disposés à la surface d'une coque de navire, il est connu de réaliser un dôme en forme de coque, en un matériau composite constitué de nappes tissées de fibres de verre, imprégnées par une résine polyester. Ce matériau a un module d'élasticité (défini par le rapport entre la contrainte appliquée et la déformation résultante) de valeur telle qu'il conduit à des épaisseurs de coque relativement grande, entraînant une mauvaise transmission.It is known, in particular from French patent application No. 2 069 875, filed by the Applicant, to produce massive domes in thermoset polyurethane. Since this material is soft, it makes it necessary to produce massive domes which are ill-suited when it comes to coating antennas of ellipsoidal or spherical shape because then these antennas are no longer accessible. In addition, around 0 ° Celsius, the sound transmission coefficient of this material becomes poor. This phenomenon is annoying because it sometimes takes several hours for the mass of the material to resume the temperature of the water. For the protection of antennas whose transducers are arranged on the surface of a ship's hull, it is known to produce a dome in the form of a hull, in a composite material consisting of webs woven from glass fibers, impregnated with a resin. polyester. This material has a modulus of elasticity (defined by the ratio between the applied stress and the resulting deformation) of such value that it leads to relatively large shell thicknesses, resulting in poor transmission.
On connait par ailleurs un matériau composite constitué de fibres de carbone imprégnées d'une résine, dont le module d'élasticité est plus élevé, mais on ne réalise pas de dômes entièrement avec ce matériau parce qu'il est plus coûteux. Par contre, on réalise des dômes en fibres de verre et résine de polyester dans lesquels sont ménagées des fenêtres acoustiques en fibres de carbone pour améliorer la transmission. Ces fenêtres sont constituées de fibres de carbone imprégnées de résine polyester remplaçant une partie de l'épaisseur de la coque en fibres de verre et résine de polyester, du côté intérieur de la coque. Cependant cette structure garde l'inconvénient d'être lourde, et est délicate à construire.We also know a composite material consisting of carbon fibers impregnated with a resin, whose elastic modulus is higher, but we do not make domes entirely with this material because it is more expensive. On the other hand, we realize domes in glass fibers and polyester resin in which windows are provided carbon fiber acoustics to improve transmission. These windows are made of carbon fibers impregnated with polyester resin replacing part of the thickness of the hull in glass fibers and polyester resin, on the inner side of the hull. However, this structure retains the disadvantage of being heavy, and is difficult to build.
Le but de l'invention est de réaliser un dôme ayant un faible poids et une bonne transmission acoustique, tout en étant facile à construire. L'objet de l'invention est un dôme en matériau composite de type sandwich comportant une couche de fibres de verre et deux couches de fibres de carbone, imprégnées d'une résine, combinées de façon à éviter les inconvénients des dômes de types connus.The object of the invention is to produce a dome having a low weight and good acoustic transmission, while being easy to construct. The object of the invention is a dome of composite material of the sandwich type comprising a layer of glass fibers and two layers of carbon fibers, impregnated with a resin, combined so as to avoid the drawbacks of domes of known types.
Selon l'invention, un dôme pour sonar est caractérisé en ce qu'il comporte une paroi comportant une couche centrale formée de plusieurs nappes tissées en fibres de verre, imprégnées d'une résine, et de deux couches périphériques, situées de part et d'autre de la couche centrale, et formées de plusieurs nappes tissées en fibres de carbone, imprégnées d'une résine.According to the invention, a sonar dome is characterized in that it comprises a wall comprising a central layer formed by several layers woven in glass fibers, impregnated with a resin, and by two peripheral layers, located on the right and 'other of the central layer, and formed of several layers woven of carbon fibers, impregnated with a resin.
L'invention sera mieux comprise et d'autres détails apparaîtront à l'aide de la description ci-dessous et des figures s'y rapportant :
- - la figure 1 montre en coupe un exemple de dôme de sonar selon l'invention ;
- - la figure 2 montre, en l'agrandissant, une coupe de la paroi de cet exemple de réalisation ;
- - la figure 3 montre le tissage d'une des nappes de fibres de carbone que comporte cet exemple de réalisation.
- - Figure 1 shows in section an example of a sonar dome according to the invention;
- - Figure 2 shows, by enlarging, a section of the wall of this exemplary embodiment;
- - Figure 3 shows the weaving of one of the layers of carbon fibers that this exemplary embodiment comprises.
Sur la figure 1, le dôme a une forme de coque dont la paroi 3 est réalisée en une seule pièce, boulonnée sur son pourtour à la coque 1 d'un navire. Une antenne de sonar, 2, fixée à la coque 1 du navire, est située dans le creux du dôme et baigne dans de l'eau 4, retenue par le dôme.In Figure 1, the dome has a hull shape whose wall 3 is made in one piece, bolted on its periphery to the hull 1 of a ship. A sonar antenna, 2, fixed to the hull 1 of the ship, is located in the hollow of the dome and bathes in
La figure 2 montre, en l'agrandissant, une coupe de la paroi 3. Elle est composée d'un sandwich formé de trois couches :
- deux couches périphériques 6 et 8, constituées de trois nappes tissées, appelées "plis", formées de fibres de carbone ;
- une couche centrale 7 constituée de huit plis de fibres de verre.Figure 2 shows, by enlarging it, a section of the wall 3. It is composed of a sandwich formed of three layers:
- two
- A central layer 7 consisting of eight plies of glass fibers.
Les trois couches 6, 7, et 8 sont imprégnées d'une résine époxyde thermodurcissable. Pendant le durcissement de la résine, ces trois couches sont pressées fortement entre elles et polymérisées, dans une étuve, avec une élévation de température et de pression adaptées à la résine utilisée et dont le choix est à la portée de l'homme de l'art.The three
La couche centrale a une épaisseur de 5 mm. Les deux couches périphériques ont une épaisseur identique : 1,5 mm, afin d'obtenir une stabilité du matériau d'un point de vue mécanique et thermique, c'est-à-dire éviter des déformations dues aux contraintes mécaniques ou thermiques.The central layer has a thickness of 5 mm. The two peripheral layers have an identical thickness: 1.5 mm, in order to obtain a stability of the material from a mechanical and thermal point of view, that is to say avoid deformations due to mechanical or thermal stresses.
Le dôme selon l'invention a une bonne transmission acoustique et une grande résistance à la flexion grâce aux fibres de carbone qui se trouvent éloignées de l'axe neutre.The dome according to the invention has good acoustic transmission and great resistance to bending thanks to the carbon fibers which are located far from the neutral axis.
La figure 3 représente un exemple de tissage d'un des plis de fibres de carbone constituant les couches 6 et 8. Des mèches de fibres de carbone sont croisées avec un pas identique, par exemple 3, dans le sens transversal et un pas de 3 dans le sens longitudinal en raison de la raideur des fibres de carbone. Le tissage des plis de fibres de verre, qui n'est pas représenté, est réalisé avec un rapport de 1/1.FIG. 3 represents an example of weaving one of the plies of carbon fibers constituting the
La paroi ainsi réalisée a un module d'élasticité en traction de 28 Gigapascals avec un coefficient de transmission acoustique de 98%. Si le dôme avait été fabriqué entièrement en fibres de verre et en résine de polyester, l'épaisseur nécessaire pour obtenir la même résistance aurait été de 16 mm et aurait donné un coefficient de transmission voisin de 92%. De plus le gain en poids est dans un rapport 2.The wall thus produced has a tensile elasticity module of 28 Gigapascals with an acoustic transmission coefficient of 98%. If the dome had been made entirely of glass fibers and polyester resin, the thickness necessary to obtain the same resistance would have been 16 mm and would have given a transmission coefficient close to 92%. In addition, the weight gain is in a
L'invention n'est pas limitée à cet exemple de réalisation. Il est à la portée de l'homme de l'art d'utiliser un type de résine autre que les résines époxydes, par exemple une résine thermoplastique.The invention is not limited to this exemplary embodiment. It is within the reach of those skilled in the art to use a type of resin other than epoxy resins, for example a thermoplastic resin.
Il est possible aussi d'utiliser une résine différente dans chaque couche. Par exemple, une résine particulièrement appropriée pour les fibres de carbone peut être utilisée dans les deux couches périphériques et une autre résine, particulièrement appropriée pour les fibres de verre, peut être utilisée pour la couche centrale.It is also possible to use a different resin in each layer. For example, a resin particularly suitable for carbon fibers can be used in the two peripheral layers and another resin, particularly suitable for glass fibers, can be used for the central layer.
Suivant une variante, la paroi du dôme selon l'invention peut comporter des couches supplémentaires de matériaux ayant une bonne transparence acoustique, par exemple une couche externe en fibres aramides imprégnées de résine époxyde, pour obtenir une résistance aux chocs particulièrement élevée.According to a variant, the wall of the dome according to the invention may comprise additional layers of materials having good acoustic transparency, for example an outer layer of aramid fibers impregnated with epoxy resin, to obtain a particularly high impact resistance.
Claims (4)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8514767 | 1985-10-04 | ||
| FR8514767A FR2588408B1 (en) | 1985-10-04 | 1985-10-04 | DOME FOR SONAR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0219421A1 true EP0219421A1 (en) | 1987-04-22 |
| EP0219421B1 EP0219421B1 (en) | 1990-02-07 |
Family
ID=9323557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP86402194A Expired - Lifetime EP0219421B1 (en) | 1985-10-04 | 1986-10-03 | Sonar dome |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4770267A (en) |
| EP (1) | EP0219421B1 (en) |
| AU (1) | AU581348B2 (en) |
| CA (1) | CA1280503C (en) |
| DE (1) | DE3669002D1 (en) |
| FR (1) | FR2588408B1 (en) |
| NO (1) | NO863830L (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0311783A2 (en) * | 1987-10-13 | 1989-04-19 | The B.F. Goodrich Company | A high sonar transmission composition |
| EP0460246A1 (en) * | 1986-05-21 | 1991-12-11 | The B.F. Goodrich Company | Window for acoustic wave form and method for making |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USH1650H (en) * | 1993-02-26 | 1997-06-03 | The United States Of America As Represented By The Secretary Of The Navy | Impervious cable connected electrical component assembly |
| US6831876B1 (en) * | 2003-07-09 | 2004-12-14 | Goodrich Corporation | Acoustic window |
| US7408842B2 (en) * | 2006-03-30 | 2008-08-05 | Materials Sciences Corporation | Sonar dome |
| US9411040B2 (en) * | 2014-06-23 | 2016-08-09 | Goodrich Corporation | Systems and methods for acoustic windows |
| CN109788404A (en) * | 2018-12-29 | 2019-05-21 | 瑞声科技（南京）有限公司 | Vibrating diaphragm and microphone device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2069875A1 (en) * | 1969-11-25 | 1971-09-10 | Thomson Csf | |
| US3858165A (en) * | 1970-07-29 | 1974-12-31 | Haveg Industries Inc | Acoustical window for sonar systems |
| US4307457A (en) * | 1979-02-05 | 1981-12-22 | Fleet Industries | Slamming-resistant sonar dome canoe |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3123176A (en) * | 1964-03-03 | greenberg | ||
| US3136380A (en) * | 1959-10-15 | 1964-06-09 | Riverside Plastics Corp | Sonar dome and self-damping component thereof |
| US3038551A (en) * | 1959-10-15 | 1962-06-12 | Riverside Plastics Corp | Self-damping material and sonar dome formed therefrom |
| US3426725A (en) * | 1967-07-07 | 1969-02-11 | Simonsen & Mustad As | Sonar systems in vessels |
| US4237176A (en) * | 1976-05-27 | 1980-12-02 | Ferro Corporation | Moldable sound control composite |
| US4062422A (en) * | 1976-06-21 | 1977-12-13 | The United States Of America As Represented By The Secretary Of The Navy | Antifouling damping system for sonar domes |
-
1985
- 1985-10-04 FR FR8514767A patent/FR2588408B1/en not_active Expired
-
1986
- 1986-09-25 NO NO863830A patent/NO863830L/en unknown
- 1986-09-25 US US06/911,340 patent/US4770267A/en not_active Expired - Fee Related
- 1986-10-03 DE DE8686402194T patent/DE3669002D1/en not_active Expired - Fee Related
- 1986-10-03 AU AU63492/86A patent/AU581348B2/en not_active Ceased
- 1986-10-03 CA CA000519751A patent/CA1280503C/en not_active Expired - Lifetime
- 1986-10-03 EP EP86402194A patent/EP0219421B1/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2069875A1 (en) * | 1969-11-25 | 1971-09-10 | Thomson Csf | |
| US3858165A (en) * | 1970-07-29 | 1974-12-31 | Haveg Industries Inc | Acoustical window for sonar systems |
| US4307457A (en) * | 1979-02-05 | 1981-12-22 | Fleet Industries | Slamming-resistant sonar dome canoe |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0460246A1 (en) * | 1986-05-21 | 1991-12-11 | The B.F. Goodrich Company | Window for acoustic wave form and method for making |
| EP0311783A2 (en) * | 1987-10-13 | 1989-04-19 | The B.F. Goodrich Company | A high sonar transmission composition |
| EP0311783A3 (en) * | 1987-10-13 | 1991-01-30 | The B.F. Goodrich Company | A high sonar transmission composition |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2588408A1 (en) | 1987-04-10 |
| AU581348B2 (en) | 1989-02-16 |
| US4770267A (en) | 1988-09-13 |
| EP0219421B1 (en) | 1990-02-07 |
| FR2588408B1 (en) | 1987-11-20 |
| CA1280503C (en) | 1991-02-19 |
| AU6349286A (en) | 1987-04-09 |
| NO863830L (en) | 1987-04-06 |
| DE3669002D1 (en) | 1990-03-15 |
| NO863830D0 (en) | 1986-09-25 |
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