Claims
- 1. A pin-reinforced sandwich structure, comprising:
- (a) a core having opposed first and second surfaces;
- (b) a first face sheet adjacent the first surface and containing a resin;
- (c) a second face sheet adjacent the second surface and containing a resin;
- (d) a plurality of separate pins inserted into the first and second face sheets and extending through the core to form a pin-reinforced sandwich structure, and
- (e) dimples in the core adjacent and surrounding each pin and adjacent each face sheet, each dimple being filled with resin from a face sheet to produce resin fillets for improved pulloff strength of the face sheets from the core
- wherein the pins form an ordered configuration to enhance pulloff strength, the configuration being tetrahedral or hat section.
- 2. The structure of claim 1 wherein the face sheets are adhered to the core.
- 3. The structure of claim 1 wherein the core is organic matrix resin foam.
- 4. The structure of claim 1 wherein the face sheets are fiber-reinforced resin composites.
- 5. The structure of claim 1 wherein the pins are metal, graphite, glass, or carbon and have a Young's modulus of at least about 10.sup.7.
- 6. A pin-reinforced sandwich structure, comprising:
- (a) a first face sheet generally defining an X-Y plane;
- (b) a second face sheet separated from the first face sheet by an unfilled gap between the face sheets; and
- (c) a plurality of separate pins inserted into the first and second face sheets generally in a Z-direction to hold the face sheets apart and to form a pin-reinforced sandwich structure, wherein the pins are metal, graphite, glass, or carbon, have a Young's modulus of at least about 10.sup.7, and form an ordered tetrahedral or hat section configuration skew to both the X-Z and Y-Z planes.
- 7. A pin-reinforced sandwich structure, comprising:
- (a) a foam or foam-filled honeycomb core having opposed first and second surfaces;
- (b) two face sheets, one face sheet adhered to each of the first and second surfaces, each face sheet including fiber-reinforced organic matrix ream;
- (c) a plurality of separate pins at an areal density of about (0.375-1.50% inserted into the face sheets and extending through the core to provide improved pulloff strength of the face sheets from the core; and
- (d) resin fillets of the same resin as the organic matrix resin of the face sheets around each pin and penetrating into the core at the face sheet-core interface.
- 8. A pin-reinforced sandwich structure, comprising:
- (a) a core having opposed first and second surfaces, the core being foam, syntactic foam, a fiber-reinforced resin prepreg or composite, a fiberform or microform ceramic, a metal/foil hybrid laminate, or a foam-filled honeycomb;
- (b) a fiber-reinforced resin matrix face sheet adhered to each of the first and second surfaces, the surfaces defining generally an X-Y plane;
- (c) a plurality of separate stainless steel, titanium, copper, graphite, epoxy, composite, carbon, or glass pins at an areal density of about 0.375-1.50% inserted into the face sheets and extending through the core generally in a Z-direction normal to the X-Y plane; the pins having a Young's modulus of at least about 10.sup.7 ; and
- (d) resin fillets extending into the core around each pin at the face sheet-core interface.
- 9. The sandwich structure of claim 8 wherein the pins are arranged in a tetrahedral array.
- 10. The sandwich structure of claim 8 wherein the pins are arranged in a hat section array.
- 11. The sandwich structure of claim 8 wherein the pins are skew to both the X-Z and Y-Z planes.
- 12. The sandwich structure of claim 11 wherein the pins are arranged in a hat section array.
- 13. The sandwich structure of claim 11 wherein the pins are arranged in a tetrahedral array.
Parent Case Info
This application is a continuation of U.S. Ser. No. 08/628,879, filed Apr. 5, 1996, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2129931A |
Nov 1972 |
FRX |
2718670A |
Oct 1995 |
FRX |
WO 95 03170A |
Feb 1995 |
WOX |
Non-Patent Literature Citations (1)
Entry |
Horsch, "Dreidimensionale Verstackungsmaterialien fuer Faserverbundwerkstoffe," Kunstoffe, vol. 80, No. 9, (Sep. 1990), pp. 1003-1007. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
628879 |
Apr 1996 |
|