Abstract. Turbine blade which are generally made of composite is a core device among components of tidal current power generator that converts the flow of tidal current into a turning force. Recent years, damages of composite turbine blades have been reported due to reasons like seawater degradation, lake of strength, manufacture etc. In this paper, water absorption, tensile, bending, longitudinal transverse shearing properties of carbon fiber reinforced plastic (CRP) composite which would be applied to fabricate the marine current turbine blade has been investigated. Furthermore, the variations of properties with seawater immersion period were studied. The results indicated that the water absorption increased almost linearly at the beginning of immersion and then became stable. Tensile strength of specimen tended to decrease firstly and then recovered slightly. However, the longitudinal transverse shearing strength showed reverse variation trend comparing to tensile strength. And the bending property of specimens was depressed significantly. The properties variations in seawater shall be referenced to design and fabrication of composite marine current turbine blade.

Abstract.A three dimensional finite element model of the heat treatment process of ZG06Cr13Ni4Mo stainless steel was established in this paper. The distribution of stress and deformation for large hydro turbine blade with complex surface during normalizing and tempering treatment has been simulated. The simulated results are consistent with the measured equivalent stress values by hole-drilling method, which indicates that the model is effective to predict the stress distribution of heat treated ZG06Cr13Ni4Mo material. Based on this model, the distribution law of stress field and deformation of the large hydro turbine blade of complex surface after the heat treatment were simulated. The established model provided a theoretical prediction method for designing of optimized complex surface blade and formulating a reasonable heat treatment process.