Fatigue analysis method of wind turbine blade coating considering raindrop erosion

Abstract

The invention discloses a fatigue analysis method for a coating of a wind power generator blade considering raindrop erosion. The method builds a random rain field model and calculates the fatigue life of the coating of a wind power generator blade based on a crack propagation theory. The present invention innovatively proposes a random rain field model considering the shape, size, impact angle, and impact velocity of raindrops to simulate the raindrop impact process, and uses the smooth particle hydrodynamics method and finite element calculation method to analyze the impact of some raindrops on the blade coating Impact stress, use the stress interpolation method to calculate the impact stress of all raindrops in the random rainfall process, combine the impact stress to carry out fatigue analysis on the blade coating, use the stress life method to calculate the life of the fatigue crack initiation stage, and use the crack growth theory to calculate the fatigue crack growth stage Life, combined with the statistics of rainfall data, this calculation method can be used to calculate the expected fatigue life of wind turbine blade coatings under raindrop erosion.

Description

technical field [0001] The invention relates to the field of wind turbine blade design, in particular to a method for analyzing fatigue of wind turbine blade coatings considering raindrop erosion. Background technique [0002] At present, wind turbine blades are often affected by high relative velocity objects such as raindrops, atmospheric particles, and hail during use, especially at the blade tip. These impacts can lead to damage and spalling of the leading edge of the blade, thereby reducing the aerodynamic performance and power output of the wind turbine. As wind turbines continue to grow in tip speed and rotor diameter, the problem of fatigue life prediction for wind turbine blade coatings under raindrop erosion becomes more important at the design stage. [0003] In this aspect, there is currently no effective solution. The present invention combines random rain field model, smooth fluid dynamics, and fatigue crack propagation theory to predict and calculate the fati...

AI Technical Summary

Problems solved by technology

The existing impact method and energy method have certain defects in calculating the impact stress of raindrops on the blade coating. Among them, the impact method is difficult to consider the fluid-solid interaction during the impact of raindrops, and the energy method is difficult to quantify the impact from random rain fields to wind turbines. The total transferred energy of the blade coating

At present, the calculation of fatigue life of wind turbine blade coating under raindrop erosion is usually done by applying the stress-life curve and the linear accumulation of fatigue damage, but the life calculated by this method is only limited to the initiation period of fatigue cracks. Fatigue damage needs to go through three stages: crack initiation, crack stable growth and crack instability growth. Traditional fatigue analysis and calculation methods cannot completely calculate the fatigue life of fan blade coatings.

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