波浪荷载作用下海上变电站动力响应分析

Dynamic response analysis of offshore substationunder action of wave load

海上升压站投资大,结构重要性等级高.采用MATLAB程序,计算Morison方程得出作用在升压站平台的波浪动力载荷,选用p-y法建立土体的非线弹性本构模型,并采用有限元软件对在波浪动载荷作用下平台结构的动力响应进行分析.通过计算可知:考虑结构动力响应结果与静力结果有一定差别,尤其是波浪谱峰频率与自振频率接近时,仅对其进行静态分析是不够的,其结果偏于危险.随机波浪荷载的波高、周期及激励方向的改变,对结构的动力响应的影响较大.响应随着波高增大而增大;在一定范围内存在临界周期,不同的波浪周期,响应并不一致,小于临界周期,响应比其临界周期大.当波浪方向坐标系与平台固定坐标系的夹角为0°时,所引起的升压站平台结构响应最大.

Offshore substation is a fundamental structure in utilizing wind resource;and its stability and safety are of vital significance.To provide technical support for its application,focusing on an offshore substation in Jiangsu Province,China,this paper has analyzed the structural dynamic response of offshore substation.The dynamic wave loads on the substation are calculated using Morison equation.A finite element model coupling nonlinear elastic soil constitutive model using p-y method is built;and the wave loads are imported to calculate the dynamic response of platform structure.The results show that:1)There is difference whether the dynamic or the static wave load is imported.Especially when the spectrum peak frequency of wave is close to the natural frequency,the results of static analysis lead to danger.2)The wave height,period and excitation orientation of wave load have a large impact on the dynamic response of structure.The dynamic response increases when wave height increases.There exists a critical period in a certain range.When wave period is lower than the critical period,the correspongding dynamic response is lager than that of critical period,and vice verse.The dynamic response is the largest when the included angle of wave excitation and fixed coordinate system is 0°.