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This paper focuses on verifying the feasibility of applying fibre reinforced polymer matrix composite to vertical axis wind turbine. A small-scale lift-type vertical axis wind turbine using glass fibre reinforced epoxy matrix sandwich composite blade was proposed. An airfoil profile of blade was designed and a composite blade was fabricated. The structure parameters of the blade were optimized by means of the finite element modeling method. The mechanical and the resonant properties of the blade were investigated. Finally, a wind turbine with the designed blade was assembled, and its generating capacity was tested. It was demonstrated that the designed composite blade and the wind turbine had excellent performance, indicating a promising technology for utilizing wind power.

Using modified SHPB device, damage behaviors of alumina/aluminum armors under impact load were studied. The influences of panel/back thickness on the target damage characteristics were investigated. The transmitted stress wave increased and the reflected stress wave decreased distinctly with the increase of back thickness, while the panel thickness variation had little influence on the stress wave propagation features. The vertex angle of ceramic inverted cone increased with the increase of back thickness and decrease of panel thickness, but the number of radial cracks reduced with the increase of back thickness and the decrease of panel thickness. Furthermore, the failure mechanism of the ceramic panels, including the cone and radial cracks formation mechanism was analyzed. A “composite beam” model has been established to estimate the local bending stress. The model calculation showed that the local bending stress is related to the panel thickness, back thickness and the panel/back moduli ratio.

A thermal expansion process was applied to prepare stitched sandwich structures using the pressure generated by the foam core inside a closed mold. In this way, buckling of stitches was avoided. The mechanical properties of the specimens prepared by thermal expansion process were significantly improved when compared to that of specimens prepared using the hot press. In order to increase the thermal expansion pressure, the foam cores were pre-compressed, and then stitched with the face sheets. The pre-compressed foam cores underwent thermal expansion easily and their thermal expansion pressure increased with increase in pre-compressive ratio.

In order to enhance the mechanical properties of B 4 C without density increase, the short carbon fibers M40, M55J and T700 reinforced B 4 C ceramic composites were fabricated by hot-pressing process. The addition of the carbon fibers accelerates the densification of the B 4 C, decreases their densities, and improves their strength and toughness. The enhancement effects of the three kinds of carbon fibers were studied by investigating the density, Vickers hardness and the mechanical properties such as flexural strength, flexural modulus and fracture toughness of the composites. The fiber type has a great influence on the mechanical properties and enhancement of the short carbon fiber reinforced B 4 C composites. The flexible carbon fiber with high strength and low modulus such as T700 is appropriate to reinforce the B 4 C matrix ceramic composites.

In order to improve the mechanical properties of boron carbide (B4C) ceramic, a mullite-reinforced B4C matrix ceramic with complete densification was fabricated via hot pressing for the first time. The dense sintering mechanism of mullite-reinforced B4C ceramic was discussed through the phase and element analysis. A new dense sintering mechanism was found in which the diffusion of Si in mullite through the B4C matrix enhances the sintering of mullite-reinforced B4C ceramics effectively. The mechanical properties and microstructure of the composite ceramics were investigated in contrast with monolithic B4C and one kind of commercial B4C ceramic. The flexural strength and fractural toughness of B4C with 3 vol% mullite addition reached 560 MPa and 3.33 MPa·m1/2, which is 154% and 96% higher than that of monolithic B4C, respectively.

By using carbon fiber (CF) as small-diameter fiber, SiC fiber (SiCF) or boron fiber (BF) as large-diameter fiber, the SiCF/CF and BF/CF fiber reinforced epoxy resin hybrid composites have been fabricated and investigated. Through SEM micrograph analysis and fiber volume fraction statistics, the hybrid fiber distribution model of bi-diameter hybrid composites has been developed. Compressive and flexural properties of both hybrid composites were tested, and then the damage characteristics and the fracture mechanism of the two kinds of hybrid composites were studied contrastively. The hybrid effect of BF/CF composites is positive, i.e., the hybrid composites have higher compressive and flexural strengths than CFRP and BFRP. In contrast, the compressive and flexural strengths of SiCF/CF composite are both between those of CFRP and SiCFRP. The simple linear addition rule slowly dominates, obviously. The flexural modulus of the two hybrid materials obeys the rule of mixture.