Fabrication and flexural characteristics of ultra-lightweight integral composite truss structure

A glass-fiber/epoxy composite truss with the triangle section and without joints was fabricated by manually guided filament winding and hand-tying with high-strength glass-fiber yarns. The design and fabrication of the mandrel，the methods of winding and hand-tying and the curing and demolding process were discussed. In order to evaluate the manufacturing quality，the diameter，fiber volume fraction and tensile properties of the ribs of the composite truss were measured. A three-point bending test was also conducted for the integral composite truss in order to evaluate the capability of resisting bending. The results show that the average error of the diameter is about 5.8%. The average value of fiber volume fraction reaches 64%. The average tensile strength and modulus are 747.5 MPa and 48.56 GPa，respectively，which are 9% and 15% higher than those of the samples prepared by compression molding process. It indicates that the manufacturing method of the manually guided filament winding cooperated with hand-tying can fabricate the composite truss with high quality. The results of the three-point bending test show that the ultra-lightweight (line density ≤1. 0 kg/m) composite truss has a good integral flexural stiffness (the buckling load is about 2000 N) .