地基基础对风力发电机塔架系统地震响应的影响研究

Study of the effects of foundation on seismic responses for wind turbine tower system

建立了风力机塔架、基础与地基的相互作用三维有限元模型,采用改进的拉格朗日有限元格式、接触问题的约束函数法和Newmark自动变步长的动力求解方法,分析了P-Δ效应、地基及地基与塔架基础的接触形式对塔架的自振特性和地震时程响应的影响。分析结果表明:弹性地基及塔架基础与地基土壤滑移接触使得塔架结构的各阶自振频率降低显著,尤其高阶频率影响更甚,同时塔架系统各地震响应值也增大很明显。研究方法和研究成果可为风力机塔架系统的抗震设计提供有益的参考。

This paper develops a 3D FEM model with interaction between wind turbine tower,concrete base and soil foundation.To consider foundation soil,this model adopts updated Lagrangian finite element format,contact constraint function method and Newmark automatic variable step length solution method.The P-Δ effect and the effects of contact manner between concrete and soil foundations on natural vibration properties of the tower and the time-domain seismic responses are analyzed.Results show that if the elastic soil foundation and the contact connection are considered,nature frequencies of the tower decrease significantly,particularly the modes of higher frequencies.The amplitudes of seismic responses of the tower structure show similar increases.This work provides method and references for seismic design of wind turbine tower.