Three-dimensional printing of locally bendable short carbon fiber reinforced polymer composites

Locally bendable solid plates were manufactured in a single 3D-printing operation, using a single material, i.e., short carbon fiber reinforced plastic (CFRP). The locally bendable CFRP plates included solid and bendable parts, which were connected seamlessly using double-stepped lap configuration. A parallel cross shape structure and 100% infill structure was adopted for the bendable and solid parts, respectively. The bendability could be controlled by varying the girder angle of the parallel cross shape structure. The bending stiffness was reduced to nearly 98% compared to that of the solid plate. The cyclic bending tests indicated that the locally bendable CFRP plate underwent reversible bending deformation. The bending stiffness decreased by approximately 8–14%. However, visible damage was not observed even after 100 cycles of bending deformation.