METHOD FOR STIFFENING PLATES INTENDED FOR THE CREATION OF SHIP WALLS AND COMPRISING LAMINATED COMPOSITE MATERIALS, AND RESULTING PLATE

Abstract

Disclosed is a method for stiffening plates for ship walls. At least one elongate profile member of laminated composite material and having a transverse cross-section of a predetermined shape over the length thereof is pre-manufactured, the profile member being rigid. Then, a panel including laminated composite materials at least on the surface of at least one of the two main surfaces thereof is used, and the at least one pre-manufactured profile member is assembled and attached together onto one of the main surfaces of the panel. The main surface of the panel receives the profile member including laminated composite material. The profile member has a transverse cross-section with three continuous portions: two flanges having substantially straight cross-sections and interconnected by a web. The flanges and the web in transverse cross-section are supported by separate planes, the plane of the web intersecting the two planes, supporting the flanges, at 90.

Claims

1-12. (canceled)

13. Method for stiffening plates (1) intended for the creation of ship walls and comprising laminated composite materials, the laminated composite materials being constituted of stacks of layers of fibres impregnated with resin, wherein, at least one elongate profile member (3a, 3b, 3c) made of laminated composite material is pre-manufactured having a transverse cross-section of a predetermined shape over the length thereof, with the pre-manufactured profile member (3a, 3b, 3c) and obtained being rigid due to the polymerization of the resin that impregnated the layers of fibres that the profile member comprises, and, and wherein a panel (2) is used having two main surfaces and comprising at least on the surface of at least one of its two main surfaces a laminated composite material, with the resin that impregnated the layers of fibres that the panel comprises being polymerized, and said at least one pre-manufactured profile member (3a, 3b, 3c) is assembled and attached together onto one of the main surfaces of said panel (2), with the main surface of the panel receiving the profile member comprising laminated composite material, and wherein the pre-manufactured profile member (3a, 3b, 3c) has a transverse cross-section of a determined shape that comprises three continuous portions: two flanges (7, 7) and a web (6), the two flanges (7, 7) and the web (6) being substantially straight in the transverse cross-section of the profile member, the two flanges (7, 7) being connected together by the web, the web (6) being connected to the flanges (7, 7) along its two opposite lateral edges, and wherein the two flanges (7, 7) and the web (6) are longitudinally extended over three separate planes, with the plane over which extends the web (6) crossing the two separate planes over which extend the flanges (7, 7), with the two planes over which extend the two flanges (7, 7) being parallel to each other and crossing the plane over which the web (6) extends with an angle of about 90, each flange (7, 7) having two main surfaces, a main inner surface on the side of the web (6) and a main outer free surface opposite the preceding one, one of the two flanges (7, 7) of the pre-manufactured profile member being applied by its main outer free surface on the panel.

14. Method according to claim 13, wherein a pre-manufactured profile member (3b) is used of which the two flanges (7) are of the same lateral side of the web, the transverse cross-section of the profile member (3b) being U-shaped.

15. Method according to claim 14, wherein in the U-shaped profile member at least one portion of the fibre layers is continuously extended from one flange to the other.

16. Method according to claim 14, wherein a pre-manufactured profile member (3a) is used of which the two flanges (7) are astride two lateral edges of the web (6), the transverse cross-section of the profile member (3a) being H-shaped, the pre-manufactured H-shaped profile member resulting from the reunion during the manufacture thereof of two U-shaped forms of composite material arranged web-against-web.

17. Method according to claim 15, wherein a pre-manufactured profile member (3a) is used of which the two flanges (7) are astride two lateral edges of the web (6), the transverse cross-section of the profile member (3a) being H-shaped, the pre-manufactured H-shaped profile member resulting from the reunion during the manufacture thereof of two U-shaped forms of composite material arranged web-against-web.

18. Method according to claim 14, wherein a pre-manufactured profile member (3a) is used that is tubular, the pre-manufactured tubular profile member resulting from the reunion during the manufacture thereof of two U-shaped forms of composite material arranged lateral end of flange against lateral end of flange.

19. Method according to claim 15, wherein a pre-manufactured profile member (3a) is used that is tubular, the pre-manufactured tubular profile member resulting from the reunion during the manufacture thereof of two U-shaped forms of composite material arranged lateral end of flange against lateral end of flange.

20. Method according to claim 16, wherein, furthermore, during the pre-manufacturing of the H-shaped or tubular profile member, a complementary layer (10) is added of complementary fibre layers on the main outer free surface of at least the flange that is not intended to be applied on the panel.

21. Method according to claim 17, wherein, furthermore, during the pre-manufacturing of the H-shaped or tubular profile member, a complementary layer (10) is added of complementary fibre layers on the main outer free surface of at least the flange that is not intended to be applied on the panel.

22. Method according to claim 18, wherein, furthermore, during the pre-manufacturing of the H-shaped or tubular profile member, a complementary layer (10) is added of complementary fibre layers on the main outer free surface of at least the flange that is not intended to be applied on the panel.

23. Method according to claim 19, wherein, furthermore, during the pre-manufacturing of the H-shaped or tubular profile member, a complementary layer (10) is added of complementary fibre layers on the main outer free surface of at least the flange that is not intended to be applied on the panel.

24. Method according to claim 13, wherein, alternatively, a pre-manufactured profile member (3c) is used of which the traverse cross-section is T-shaped with a single flange (7) astride one of the two lateral edges of the web (6) and wherein during the assembly and the fastening to the panel of the pre-manufactured profile member, the lateral free edge of the web (6) of the pre-manufactured profile member is placed on the main surface of the panel (2) and the second flange, on the panel (2) side, is created, by lamination (3d) of additional layers of fibres extended between the web (6) and the panel (2) as well as resin (5), this for the two lateral sides of the web (6), in order to obtain a fixed H-shaped profile member with a transverse cross-section.

25. Method according to claim 13, wherein the pre-manufactured profile members (3a, 3b, 3c) are fixed to the panels (2) by at least one of the following techniques: gluing (4, 5) or mechanical clamping, the gluing being carried out with or without adding additional layers of fibres, the mechanical clamping being chosen from screwing, bolting, riveting, the gluing being in particular a vacuum gluing.

26. Method according to claim 13, wherein, for at least one of the two flanges (7, 7), the main inner surface of the flange comprises towards it free end, in the case of a U-shaped profile member (3b), or at least one of its two free ends, in the case of an H-shaped or T-shaped profile member (3a, 3c), a return (8) intended to form a chute (9) delimited laterally by the web (6) and the return (8) and delimited at the bottom by the main inner surface of the flange (7, 7).

27. Method according to claim 13, wherein layers of oriented fibres are used and between them are crossed the various layers of fibres.

28. Reinforced plate (1) for a ship wall comprising laminated composite materials, wherein it is specifically obtained through the method of claim 13.

29. Reinforced plate (1) for a ship wall comprising laminated composite materials, wherein it is specifically obtained through the method of claim 16.

30. Reinforced plate (1) for a ship wall comprising laminated composite materials, wherein it is specifically obtained through the method of claim 20.

31. Reinforced plate (1) for a ship wall comprising laminated composite materials, wherein it is specifically obtained through the method of claim 24.

32. Ship comprising at least one reinforced plate according to claim 30, said ship being a surface craft or a semi-submersible or submersible craft.

Description

[0061] In the accompany drawings:

[0062] FIG. 1 is a transverse cross-section view of a pre-manufactured H-shaped profile member, made of composite, and which has been assembled and fixed onto a composite panel,

[0063] FIG. 2 is a transverse cross-section view of a pre-manufactured U-shaped profile member, made of composite, and which has been assembled and fixed onto a composite panel,

[0064] FIG. 3 is a transverse cross-section view of an H-shaped stiffener created from a T-shaped pre-manufactured profile member, made of composite, and which has been assembled and fixed onto a composite panel with over laminating on the side of the panel, and

[0065] FIG. 4 is a transverse cross-section view of a pre-manufactured H-shaped profile member, made of composite, and which has been assembled and fixed onto a composite panel, said pre-manufactured profile member having two chutes due to the presence of two returns at the two free lateral ends of flanges.

[0066] In relation with FIGS. 1 to 4 which are transverse/cross-section views, a reinforced/rigidified plate shall be described obtained by using pre-manufactured profile members of the invention. In these figures, a floor or a deck or a partition was created and it will be returned when it is installed in the structure of the ship, this explaining that the profile members are shown from the top, a position that facilitates the creating of the plate in question. Once this plate is in place in the structure of the ship, the profile members will be downwards, at the ceiling. In an alternative with a double plate, a second panel can be fixed on the flange represented as free, the one at the top, in these figures, with the double plate as such being comprised of two panels that are parallel to each other and connected by the pre-manufactured profile members.

[0067] The stiffening elements which are, in the scope of the invention, pre-manufactured profile members made of composite material, are arranged for example in strips or alignments that are parallel or not on the panel and according to a periodicity that depends on the desired resistance for the plate. These strips or alignments that are periodic or not can also be crossed between them.

[0068] Generally, the profile members are elongate elements that have a transverse cross-section of a determined shape comprising three continuous portions: two flat flanges in a straight profile member, straight if the section of the profile member is considered, and connected together by a flat web in a straight profile member, straight if the section of the profile member is considered. The flanges and the web when they are viewed as a transverse cross-section of the profile member are carried by separate axes, with the axis carrying the web crossing the two axes carrying the flanges typically at 90 and the two axes carrying the flanges are parallel to one another.

[0069] In FIG. 1, the plate 1 comprises a panel 2 made of laminated composite material whereon in fixed a pre-manufactured profile member 3a with a transverse cross-section in the shape of an H made of laminated composite material. The panel 2 is substantially flat and the profile member 3a is a straight elongate element. The pre-manufactured profile member 3a comprises, seen as a transverse cross-section, two straight opposite flanges 7 and separated by a straight web 6, with the flanges being perpendicular to the web and being astride on the two opposite lateral edges (top and bottom in the figures with a transverse/cross-section) of the web. The flanges in this straight profile member are flat over their length and are carried by two planes that are parallel to one another. The web is flat over its length and is carried by a median plane that crosses the two planes carrying the flanges at 90. The pre-manufactured profile member which is installed on the panel 2 is structurally rigid. This pre-manufactured profile member 3a is obtained by stacking layers (or fabrics) of fibres which are finally taken in the resin. The layers (or fabrics) of fibres are continuous from one flange to the other by passing through the web. Typically, this is a composite made of oriented glass fibres and resin and the layers (or fabrics) of fibres are crossed between them at +/45 in the stack of the layers. Furthermore, during the pre-manufacturing of the profile member, on the free surface of the flange which is the main outer surface of the flange (=surface of the flange on the side opposite the web), is furthermore disposed a complementary layer 10 of complementary layers (or fabrics) of fibres, with the whole also being taken by the resin. This complementary layer 10 can concern the free flange (the one that is not fixed to the panel) as shown in the figures or the other flange (not shown) or the two flanges of the profile member (not shown). Preferably, the orientation of the complementary layers of fibres of this additional layer 10 is 0, i.e. in the longitudinal direction of the profile member. It shall be seen, in a particular embodiment, this pre-manufactured H-shaped profile member can result from a joining of two U-shaped forms of composite material. In another embodiment, this H-shaped profile member is manufactured in a single operation.

[0070] The flange 7, on the panel side 2, is fastened to the latter via structural gluing 4. As an alternative or a complement, a fastening via over-laminating and therefore with the adding of layers of fibres and resin, is possible. The gluing and/or the bonding with resin of the pre-manufactured profile members on the plate can use all the known techniques, in particular with regards to the adding of resin and/or of adhesive, with these elements being identical or not: the gluing of the pre-manufactured profile member that can be done with a compound corresponding to the resin used for creating the composite or another specific compound for gluing. For the taking of the resin and of the glue the same technique (for example heating, radiation, hardener/catalyst) can be used or a different technique. The profile members can, for example, be created via infusion, contact, pre-preg where the layers of fibres used are pre-impregnated with resin or, pultrusion of extrusion-drawing of the layers of fibres.

[0071] In FIG. 2, the plate 1 comprises a panel 2 made of composite material whereon is fixed a pre-manufactured profile member 3b with a transverse cross-section in the shape of a U. In relation to the pre-manufactured H-shaped profile member of the preceding figure, the flanges 7 are arranged laterally to a single and same lateral side of the web 6 but always towards the lateral edges (top bottom in figure) of the web. In an alternative not shown, the flanges can be on the lateral opposite sides, still without overlapping, of the web, with the transverse cross-section shape of the profile member then being closer to a Z than a U. In another alternative, one of the two flanges can be overlapping while the other is not. As hereinabove the layers of fibres are shown continuously extended between the two flanges by passing through the web and a complementary layer 10 is created on the free flange.

[0072] As an alternative embodiment, on the plate 1 of FIG. 3, there is indeed a stiffening element with transverse cross-section in the shape of an H but it was obtained from a T-shaped pre-manufactured profile member 3c. For this, during the assembly and the fastening on the panel of the T-shaped pre-manufactured profile member 3c, the T-shaped pre-manufactured profile member T 3c was arranged against the panel 2 by the free lateral end (without flange, the one at the bottom in the figure) of its web 6 and layers of fibres 3d were extended on each side between the web and the panel, with the whole then being taken in the resin in order to ensure a structural gluing 5 of the T-shaped profile member 3c on the panel 2. With respect to the preceding examples, this solution requires an additional step of placing additional layers of fibres and of bonding with resin/gluing these additional layers, with the preceding examples requiring only a bonding with resin/gluing of the pre-manufactured profile member 3a, 3b on the panel 2. The layers of fibres are continuously extended between the flange and the web and a complementary layer 10 is created on the free flange. In less effective alternatives, it is possible to create an L-shaped pre-manufactured profile member with transverse cross-section therefore of which the flange is no longer astride on the lateral edge of the web and/or an additional placing of layers of fibres 3d only on a single side of the web of the T-shaped or L-shaped profile member.

[0073] In FIG. 4, a reinforced plate 1 of that of the type of FIG. 1 is considered but the pre-manufactured H-shaped profile member 3a that was used comprises this time chutes 9 obtained by creating returns 8 on the lateral ends of the free flange 7. These returns are oriented on the side of the web and are substantially parallel to the latter. These chutes can be used as a passage for cables or pipes. In an alternative as a complement or independently of the return 8, a metal chute or a metal strip is incorporated or glued/taken on the surface of the flange and possibly of the web and/or, optionally as a return, during the pre-manufacturing of the profile member, in the case where a relative shielding or a continuous ground/mass protection would be required.

[0074] Finally, in certain embodiments, through-openings can be pre-manufactured in the web in order to allow for the passage of ducts or cables through the web of the profile member.

[0075] A preferred embodiment of the pre-manufacturing of profile members of the invention shall now be described.

[0076] The base shape for the manufacturing of profile members is the U-shaped traverse cross-section, with the two flanges of the same lateral side of the web, with these three portions being substantially perpendicular between them. This U-shaped profile member is created via stacking of layers of fibres, more preferably of orientations crossed between them for the oriented layers. The layers are also continuous from one flange to the other for most of the layers or, better, all the layers. Once the resin soaking the fibres of the layers is polymerized/solidified, the pre-manufactured U-shaped profile member and which is rigid is obtained.

[0077] Preferably, the H-shaped pre-manufactured profile member with two flanges is obtained from the preceding U-shape form by joining/fastening web-against-web of two U-shaped profile members. For this it is possible, either to use two pre-manufactured U-shaped profile members and therefore rigid and joining and fastening together which makes it possible to obtain the H-shaped profile in two steps, or creation via stacking of layers of fibres with two U-shaped forms joined web-against-web and of which the resin is then polymerized, which makes it possible to directly obtain the rigid H-shaped profile member, in a single step. Given this embodiment wherein the layers of fibres are wholly separated into two sets belonging to the two lateral portions (each one as a U) of the H-shaped profile member, complementary extended layers of fibres are added between these two lateral portions and therefore extended at least on the main free outer surface of the flange. These complementary layers being of course also taken in the resin in order to form the pre-manufactured H-shaped profile member.

[0078] Alternatively, two U-shaped pre-manufactured profile members, instead of being joined web-against-web in order to form an H-shaped profile member, can be joined by the lateral ends of their respective flanges in order to form a tubular profile member with a substantially square or rectangular section according to the initial shapes of the U-shaped profile member, with complementary layers of layers of fibres being preferably created on these joined flanges in order to reinforce the fastening of the two U-shaped profile members.

[0079] Equivalently, a T-shaped or Z-shaped profile member can be manufactured from two joined L-shaped profile members and an H-shaped profile member can be manufactured from four joined L-shaped profile members. Other combinations are possible, for example to manufacture an H-shaped profile member it is possible to take a Z-shaped profile member and two L-shaped profile members. However, it is preferably chosen the embodiment that makes it possible to obtain the pre-manufactured profile member which is the more resistant in the application under consideration and this is in particular the case with H-shaped profile members obtained from two U-shaped profile members and with complementary layers of fibres on the flanges.

[0080] It is understood that the invention can be broken down in many other ways in the framework of the claims of this application. It is possible for example to create pre-manufactured T-shaped or L-shaped profile members with a single flange and it is fixed to the panel via this flange. Likewise, certain configurations of profile members, in particular U or L-shaped, allow for a fastening of the pre-manufactured profile member via application of the web on the panel instead of using the flange. For example, it is possible to pre-manufacture connecting profile members with an X or T or V shape as seen from above or from below or according to other shapes that correspond to a crossing or a connection between stiffening elements arranged according to longitudinal orientations that lead them to cross each other. As such, at the foreseen location of the crossing the pre-manufactured connection in the shape of an X will be arranged and its arms/branches will be extended by the pre-manufactured linear profile members described. Preferably, the transverse cross-sections of the arms of the pre-manufactured connection and of the pre-manufactured profile members that pursue them will be identical, for example all in H.

[0081] Moreover, particular shapes of the longitudinal ends of the profile members and/or connections can be provided, these forms being complementary between two ends of two profile members placed end-to-end, for example via partial overlapping or nest of ends. These shapes can, in particular, make it possible to provide a certain maintaining between the two profile members. Alternatively, or as a complement, pre-manufactured composite splice bar connectors can be fastened to the two longitudinal ends placed end-to-end of two profile members. Alternatively, pre-manufactured splice bars of a suitable shape, in particular an L, can be created for the perpendicular fastening between a longitudinal end of a first profile member and a full field, laterally, of a second profile member. In certain alternatives, one or several splice bars can be fastened or created at the origin on the pre-manufactured profile member.

[0082] By way of example of a pre-manufactured combination of connection or crossing and of complementary longitudinal ends, a crossing or a connection is created of which the longitudinal ends of arms are hollow and wherein the longitudinal ends of the profile members are nested are inserted.

[0083] Finally, although examples of applications with flat panels have been given, the invention can perfectly be applied to panels with a curved shape, the pre-manufactured profile members then being created curved with a shape complementary to that of the panel.