We introduce a fabrication method of doubly-curved shell structures by CFRP with control over fiber directions. Doubly-curved surfaces are tessellated into structured quadrilateral patches according to the purpose of use. One can design the tessellation in the parameter space, and map it to the 3D parametric surface, or use the orthogonal net of curves on surfaces such as lines of curvature, principal stretch lines, and principal stress lines. These patches, which we call generalized principal patches, are flattened onto a plane, and connected one by one by aligning the equi-length adjacent edges using translations and rotations forming generalized principal strips. Carbon fiber tows are placed onto these strips with one stroke by tailored fiber placement embroidery machines so that the fibers are not disconnected within strips. Preforms are stacked layer by layer into a mold of particular parts, and VaRTM or L-RTM method is employed to fabricate CFRP parts. We demonstrated the effectiveness of our proposed method by manufacturing an automobile hood and a marine propeller blade.

我们介绍了一种通过控制纤维方向的CFRP制作双弯曲壳结构的方法。根据使用目的，将双曲线表面细分为结构化的四边形斑块。可以在参数空间中设计细分，然后将其映射到3D参数化曲面，或者使用曲面上的曲线正交网（例如曲率线，主拉伸线和主应力线）。这些补丁（我们称为广义主补丁）被展平到一个平面上，并通过平移和旋转来对齐等长相邻边，从而形成广义主条，从而将它们一个接一个地连接。碳纤维丝束通过量身定制的绣花机一键放置在这些条带上，以使纤维不会在条带内断开连接。将预成型件逐层堆叠到特定零件的模具中，然后使用VaRTM或L-RTM方法制造CFRP零件。我们通过制造汽车引擎盖和船用螺旋桨叶片证明了我们提出的方法的有效性。