Laminate of metal sheets and polymer
View Patent ↗The invention relates to a laminate of metal sheets and fiber-reinforced polymer layers connected thereto. The laminate comprises at least one thick metal sheet with a thickness of at least 1 mm that is connected to the rest of the laminate by means of at least one fiber-reinforced polymer layer, the fiber volume content of which is at most 45 volume-%. The invention also relates to a method for producing the laminate as well as skin sheets reinforced with the laminate for an aircraft or spacecraft.
1. A structure comprising:
a laminate including at least a first metal layer having a thickness of at most about 0.8 mm, at least a second metal layer having a thickness of at most about 0.8 mm, and a fiber-reinforced polymer layer having a fiber volume content of at least about 50% therebetween;
at least one upper metal layer connected to a top of the laminate and having a constant thickness of at least about 1.0 mm; and
at least one lower metal layer connected to a bottom of the laminate and having a constant thickness of at least about 1.0 mm,
wherein the at least one upper metal layer connects to the laminate by a first fiber-reinforced polymer layer having a fiber volume content not exceeding about 45%, and wherein the at least one lower metal layer connects to the laminate by a second fiber-reinforced polymer layer having a fiber volume content not exceeding about 45%.
2. The structure of claim 1 wherein each of the first fiber-reinforced polymer layer having a fiber volume content not exceeding about 45% and the second fiber-reinforced polymer laying having a fiber volume content not exceeding about 45% includes reinforcing fibers embedded in a polymer matrix.
3. The structure of claim 2 wherein the reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, metal fibers, drawn thermoplastic fibers, natural fibers and combinations thereof.
4. The structure of claim 2 wherein the polymer matrix is a thermoplastic polymer matrix or a thermosetting polymer matrix.
5. The structure of claim 1 wherein the at least one upper metal layer and the at least one lower metal layer includes an aluminum alloy.
6. The structure of claim 1 wherein the laminate is a pre-stressed fiber metal laminate having an average compressive stress in both the at least first metal layer and the at least second metal layer and an average tensile stress in the fiber-reinforced polymer layer in an unloaded state.
7. The structure of claim 1 wherein the at least first metal layer and the at least second metal layer of the laminate has a higher yield stress than the at least one upper metal layer and the at least one lower metal layer.
8. The structure of claim 2 wherein the reinforcing fibers are impregnated with the polymer matrix in a partially cured state.
9. The structure of claim 1 for use as a skin sheet for an aircraft.