论文部分内容阅读
近海风力发电结构是由无限域地基、基础及上部结构组成的体系,有限域透射人工边界和地震动输入模式直接影响结构体系的动力响应。首先,建立透射人工边界-地基-基础-塔筒结构和固定边界-地基-基础-塔筒结构的有限元模型;然后,简要澄清了透射边界地震动输入之所以采用外力而不采取地震动物理量(加速度、速度和位移)的原因所在;最后,对给出的3种作用模式:(1)固定边界地震动输入,(2)只考虑外源输入波作用,(3)同时考虑外源输入波和内源振动的散射波作用,分别进行计算分析和比较。通过数值计算并结合理论分析,(1)澄清了对透射边界采用外力进行地震激励输入的方法的原因,这种输入方法合理可靠,符合实际情况;(2)在地震波等效荷载的生成中,针对圆形横截面地基提出了一种阻尼力、刚度力的便捷性生成方法,大大减小了工作量;(3)从自身振动特点及阻尼设置角度,解释了地震作用下采用透射边界比采用固定边界时风电结构响应减小的原因;(4)指出了地震作用下透射边界地基模型在结构动力响应与倒塌计算中内源振动反射的不容忽视性。
The offshore wind power structure is composed of an infinite foundation, foundation and superstructure. The finite field transmission artificial boundary and ground motion input mode directly affect the dynamic response of the structural system. First of all, the finite element model of artificial boundary-foundation-foundation-tower structure and fixed boundary-foundation-foundation-tower structure is established. Then, the reason why the input of seismic ground motion at transmission boundary is simplified by adopting external force instead of seismic physical quantity (Acceleration, velocity and displacement). Finally, the three modes of action given are: (1) fixed boundary ground motion input, (2) only the external input wave effect, and (3) Wave and endogenous vibration of the scattering wave effect, were calculated and analyzed and compared. By numerical calculation and theoretical analysis, (1) the reasons for the seismic excitation input using the external force on the transmission boundary are clarified. The input method is reasonable and reliable and in line with the actual situation. (2) In the generation of seismic equivalent load, Aiming at the circular cross-section foundation, a method to generate the convenience of damping force and stiffness force is proposed, which greatly reduces the workload. (3) From the perspective of its own vibration characteristics and damping setting, (4) The non-negligible property of the reflection of the internal source vibration during the dynamic response and collapse calculation of the foundation under the seismic action is pointed out.