Finite element modeling method for hub of megawatt wind generating set

Abstract

The invention relates to a finite element modeling method for a hub of a megawatt wind generating set, and belongs to the technical field of wind power generation. The technical scheme comprises the following steps of: modeling a 1/3 model of the spherical hub according to the symmetry of the spherical hub to form a finite element model of the 1/3 model, and rotating finite element model of the 1/3 model to form a finite element model of the whole hub; and performing calculation and strength checking by utilizing the rotational symmetry of the spherical hub, wherein the rotational symmetry refers to that hub stress nephograms formed by applying a load on one blade and applying a load on another blade can be completely superposed after rotating 120 or 240 degrees. The method has the advantages that: for analysis on the ultimate strength of the hub, all ultimate load working conditions can be taken into account, and limitation on the condition that a certain load component reaches maximum is avoided, so that calculation reliability and comprehensiveness are improved, and a calculated amount is decreased; and for analysis on fatigue strength, the workload of calculation is greatly reduced, and working efficiency is improved.

Description

technical field [0001] The invention relates to a finite element modeling method for a hub of a megawatt-level wind power generating set, belonging to the technical field of wind power generation. Background technique [0002] At present, in the field of wind power technology, the main structural form of the wind turbine hub is "spherical". Due to the complexity of its structure, it cannot be equivalently analyzed like blades, main shafts, towers and other slender parts. Its The strength analysis (ultimate strength and fatigue strength) is mainly carried out by using the finite element method, as shown in the attached figure 1 shown. In the model, it mainly includes the main body of the hub, the pitch bearing, the blade prosthesis, and some parts of the main shaft. The basis for establishing the blade prosthesis and part of the main shaft is Saint-Venant’s principle, so that the stress at the connecting part of the hub is also close to reality. A full displacement constra...

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Problems solved by technology

However, the disadvantage of this is that it assumes that when a certain load component of a certain blade reaches the maximum, the hub bears the maximum ultimate load

To do so, it is necessary to apply six load components (Mx, My, Mz, Fz, Fy, Fz) to the root of each blade for calculation. For a fan with three blades, it is necessary to perform 18 load calculations on the model. Generally, Said that the finite element model of the wheel hub is very large, and it takes a certain amount of time to calculate each load, which is time-consuming and inefficient

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