风力发电结构有限元建模及其地震响应分析

为研究不同精细程度的风力发电结构有限元模型在不同分析目的下的适用性,基于2MW三桨叶水平轴风力发电机,采用有限元软件ANSYS建立七种不同精细程度的风力发电结构有限元模型,以风力发电结构地震响应分析为例,得到各模型的响应结果,分别从变形、内力、应力以及应力集中四个方面分析各个模型的计算结果.研究结果表明:在计算风力发电结构的变形时,由于上部机舱及叶片对其影响较小,采用低阶单元即可得到较好的模拟结果;在计算塔底截面剪力和截面弯矩时,考虑机舱及叶片的有限元模型得到的结果较为精确,单元选择时需采用高阶实体单元;不考虑叶片、轮毂以及机舱得到的塔筒截面应力离散性较大,采用壳单元可较好地模拟塔筒截面应力;叶片、机舱等上部结构对门洞局部产生的应力集中影响较大,在计算时建议应用塔筒采用壳单元、门洞局部采用实体单元的多尺度模型进行模拟.

Finite element modeling and seismic response analysis of wind turbine structures

In order to study the applicability of the finite element model of wind turbine structure with different degrees of fineness for different analysis purposes, based on the 2 MW three-blade horizontal axis wind turbines, seven finite element models of wind power generation structures with different degrees of fineness were established by using the finite element software ANSYS. The deformation, internal force, stress and stress concentration of wind turbine structure were achieved to evaluate the efficiency of each model. The results show that when calculating the deformation of wind power generation structure, numerical model with low-order elements can get better simulation results due to the fact that the upper engine room and blades have little influence on it. When calculating the shear force and bending moment of the section at the bottom of the tower, the finite element model of the engine room and blades should be considered to achieve more accurate results, so the high-order solid element should be used when selecting the element. The stress of wind turbine tower will be discrete when the coupling effect of the blades, hub and nacelle are not considered, and the shell element can better simulate the stress of wind turbine in this situation. The superstructures such as blade and nacelle have a great influence on the stress concentration of the wind turbine door opening, so it is suggested to use the multi-scale model of shell element for the tower and solid element for the door opening.