Curved panel part
A curved panel part includes: a curved panel made of metal; and a reinforcement joined to the curved panel and made of a plurality of FRP layers including continuous fibers, in which each of the plurality of FRP layers has a single fiber direction, at least one layer out of the plurality of FRP layers has a fiber direction different from that of another layer, in the plurality of FRP layers, a proportion of layers having an angular difference in the fiber direction of 30° or more is 15% or more of all of the layers, and when calculating, by defining a maximum principal curvature direction of the curved panel as a 0° direction and a direction orthogonal to the 0° direction as a 90° direction, each of a 0° direction component and a 90° direction component regarding the fiber direction of each FRP layer of the reinforcement joined to the curved panel, by using a trigonometric function, an expression (1) is satisfied.
1. A curved panel part, comprising:
a curved panel made of metal; and
a reinforcement joined to the curved panel and made of a plurality of fiber reinforced plastic (FRP) layers including continuous fibers, wherein:
each of the plurality of FRP layers has a single fiber direction;
at least one layer out of the plurality of FRP layers has a fiber direction different from that of another layer;
in the plurality of FRP layers, a proportion of layers having an angular difference in the fiber direction of 30° or more is 15% or more of all of the layers; and
when calculating, by defining a maximum principal curvature direction of the curved panel as a 0° direction and a direction orthogonal to the 0° direction as a 90° direction, each of a 0° direction component and a 90° direction component regarding the fiber direction of each FRP layer of the reinforcement joined to the curved panel, by using a trigonometric function, a following expression (1) is satisfied:
580× K ≤( A× 4+ B )/( C+D ) (1)
A: the 0° direction component of the FRP layers positioned on an outer side of a center of a sheet thickness of the reinforcement
B: the 0° direction component of the FRP layers positioned on an inner side of the center of the sheet thickness of the reinforcement
C: the 0° direction component of the plurality of FRP layers as a whole
D: the 90° direction component of the plurality of FRP layers as a whole
K: 1/curvature radius of the curved panel in the 0° direction (mm).
2. The curved panel part according to claim 1 , wherein
the reinforcement is joined to the curved panel in its area of 70% or more.
3. The curved panel part according to claim 1 , wherein
the reinforcement is joined to the entire surface of the curved panel.
4. The curved panel part according to claim 1 , wherein
a sheet thickness of the reinforcement is 2.0 times or more a sheet thickness of the curved panel.
5. The curved panel part according to claim 1 , wherein:
the curved panel is a hood or a roof panel of an automobile; and
the reinforcement is joined to a lower surface of the curved panel.
6. The curved panel part according to claim 1 , wherein:
the curved panel is a fender, a door outer panel, or a side outer panel of an automobile; and
the reinforcement is joined to a vehicle-interior side surface of the curved panel.
7. The curved panel part according to claim 1 , wherein
the curved panel is a steel sheet with 440 MPa or more.
8. The curved panel part according to claim 1 , wherein
the FRP is a carbon fiber reinforced plastic (CFRP).
9. The curved panel part according to claim 1 , wherein
the FRP is a glass fiber reinforced plastic (GFRP).