Fiber architecture optimization for ceramic matrix composites
Creating a ceramic matrix structure may include alternating different layers of fiber fabric to achieve porosity, infiltration, and/or other objectives. Different layers of the ceramic matrix structure may be configured differently to achieve different objectives in different regions of the ceramic matrix structure. The fiber tow spacing, fiber count and/or other characteristics may be varied within individual layers and/or among different layers of the ceramic matrix structure.
1. A method of fabricating a composite material part for a turbine engine, the composite material comprising fiber reinforcement densified by a ceramic matrix, the method comprising the steps of:
employing a computing system to design a fiber architecture for a ceramic matrix composite based on performance requirements input; and
creating the fiber architecture, the creating comprising:
alternating layers of fiber fabric, each layer of fiber fabric comprising a plurality of fiber tows including longitudinal tows arranged in a longitudinal direction and a transverse tows arranged in a transverse direction with respect to the longitudinal tows, at least two of the layers having a different fiber tow spacing, and
arranging the layers in a layup so as to create internal regions in which the fiber tows of adjacent layers do not overlap each other such that varying-sized void spaces are created within the fiber architecture, the varying-sized void spaces extending completely through the layers in a top view of an area of the layup,
wherein the varying-sized void spaces form a portion of the area in the top view as open space, wherein the at least two layers include a first layer having a first plurality of first longitudinal tows that are uniformly spaced apart and a second layer overlying the first layer and having a second plurality of second longitudinal tows that are uniformly spaced apart,
wherein two adjacent first longitudinal tows of the first plurality of longitudinal tows each have an inboard edge facing the other of the two adjacent first longitudinal tows, and
wherein in the top view one of the second plurality of second longitudinal tows is spaced between the two adjacent first longitudinal tows and has a first edge that is aligned with the inboard edge of one of the two adjacent first longitudinal tows and a second edge that is spaced apart from the inboard edge of the other of the two adjacent first longitudinal tows for forming the varying-sized void spaces.
2. The method of claim 1 , comprising orienting one of the layers of the fiber fabric at an acute angle with respect to the orientation of another of the layers of the fiber fabric in the composite material.
3. The method of claim 1 , comprising positioning the fiber tows of one of the layers of the fiber fabric at an offset with respect to a position of the fiber tows of another of the layers of the fiber fabric in the composite material.
4. The method of claim 3 , comprising positioning the longitudinal tows of the one of the layers of the fiber fabric at a longitudinal offset with respect to a position of the longitudinal tows of the another of the layers of the fiber fabric.
5. The method of claim 4 , comprising positioning the transverse tows of the one of the layers of fiber fabric at a transverse offset with respect to a position of the transverse tows of the another of the layers of fiber fabric.
6. The method of claim 5 , comprising spacing the longitudinal tows of the one of the layers of fiber fabric to align the longitudinal tows of the another of the layers of fiber fabric with one or more of the varying-sized void spaces between the longitudinal tows of the layer of fiber fabric.
7. The method of claim 6 , comprising spacing the transverse tows of the one of the layers of fiber fabric to align the transverse tows of the another of the layers of fiber fabric with one or more of the varying-sized void spaces between the transverse tows of the layer of fiber fabric.