EP 0740287 A1 19961030 - Composition absorbing acoustic waves, particularly for submarine environment
Title (en)
Composition absorbing acoustic waves, particularly for submarine environment
Title (de)
Werkstoff zur Schalldämpfung, insbesondere für Unterwasseranwendungen
Title (fr)
Matériau absorbant les ondes sonores, notamment en acoustique sous-marine
Publication
Application
Priority
FR 9505050 A 19950427
Abstract (en)
The absorbent material consists of a panel (5) of a viscoelastic material, in which metal rods (6) are embedded. The panel is made, for example, from a polyurethane-type resin such as Hexcel UR 267 (RTM) and measuring 900 x 900 mm by 40 mm thick, while the metal rods are of steel and measure 20 mm long by 2 mm in diameter, with a minimum number of air bubbles trapped in the panel. The volume of the rods represents 7.3 per cent of the total volume of the panel. The panel has a reflection coefficient of the order of -15 db at atmospheric pressure and -10 db at 40 bars or a depth of 400 m at frequencies of 20 kHz and above. The same performance is obtained at frequencies below 20 kHz by increasing the panel thickness to 50 mm. In a variant of the design the metal rods can be replaced by mineral or synthetic fibres.
Abstract (fr)
L'invention concerne un matériau absorbant les ondes sonores, notamment pour des applications sous-marines, comprenant une matrice viscoélastique dans laquelle sont réparties des tiges. Les tiges sont réparties aléatoirement ou périodiquement. Elles sont en métal. <IMAGE>
IPC 1-7
IPC 8 full level
G10K 11/165 (2006.01)
CPC (source: EP US)
G10K 11/165 (2013.01 - EP US)
Citation (search report)
- [X] EP 0530074 A1 19930303 - AUSTRALIA SONAR SYST [AU]
- [A] EP 0317380 A1 19890524 - THOMSON CSF [FR]
- [A] US 2881336 A 19590407 - ELION HERBERT A
- [A] FR 2234627 A1 19750117 - TORAY INDUSTRIES [JP]
- [A] NL 132813 A
- [A] US 3515910 A 19700602 - FRITZ RICHARD D, et al
- [A] FR 2664868 A1 19920124 - BERTIN & CIE [FR]
- [A] C.M. SAYERS ET AL.: "Ultrasonic properties of transducer backings", ULTRASONICS, vol. 22, no. 2, March 1984 (1984-03-01), GUILDFORD GB, pages 57 - 60, XP002006377
Designated contracting state (EPC)
DE GB IT NL SE
DOCDB simple family (publication)
EP 0740287 A1 19961030; FR 2733620 A1 19961031; FR 2733620 B1 19970620; NO 961690 D0 19960426; NO 961690 L 19961028; US 5803009 A 19980908
DOCDB simple family (application)
EP 96400782 A 19960411; FR 9505050 A 19950427; NO 961690 A 19960426; US 63857996 A 19960429