KETEP 세계에너지시장정보

1. A calculation method for the equivalent fatigue strain of floating wind turbine blades, which is characterized by:According to the design data of the blades of the floating wind turbine, the finite element model of the blades is constructed.According to the constructed blade finite element model, the equivalent fatigue load data considering the coupling of wind, wave and ice loads are input to obtain the strain value of the blade shell under the corresponding boundary conditions, including:According to the design load data of the blades, the Markov fatigue load matrix at each section of the floating wind turbine blade is obtained.Referring to Equation (1), the Markov load matrix is converted into an equivalent fatigue load with an S-N curve slope m=10, in which the oscillation direction load is converted according to 2 million times and the swing direction is converted according to 1 million times.F1mN1＝F2mN2 (1)F1 represents the design load of the blade element, N1 represents the design number of blade runs, F2 represents the equivalent load, N2 represents the equivalent number of times, and m represents the slope of the stress-strain curve.The conversion relationship between torque and concentration is used to convert the equivalent fatigue torque load of each section into the form of cross-sectional concentration.According to the blade finite element model, the treated equivalent fatigue load is applied at the position of the main beam, in the form of concentration data along the length of the blade section.The finite element simulation software is used to simulate the stress characteristics of the blade under the equivalent fatigue load condition, and the strain value of the blade shell is obtained.According to the obtained strain value of the blade shell, the maximum strain variable of the blade front, trailing edge and main beam structure is extracted.According to the maximum strain variable of the leading edge, trailing edge and main beam structure obtained from the obtained, combined with the blade type test and engineering practice experience, the safety margin of blade fatigue strain is evaluated.The fatigue safety of the blade is judged according to the safety margin of the evaluated blade fatigue strain.