海上风电打桩系统动力学建模与冲击动力特性分析

DYNAMIC MODELING AND IMPACT DYNAMIC CHARACTERISTIC ANALYSIS OF OFFSHORE WIND POWER PILE DRIVING SYSTEM

基于LS-DYNA建立3500 kJ海上风电打桩系统拒桩工况下的有限元模型,基于应力波原理分析打桩系统内部能量的传递和各部件的动力学响应。同时基于牛顿碰撞理论建立打桩系统的集中参数模型,该模型综合考虑各部件的质量和刚度,和有限元模型的分析结果较吻合。从而在该集中参数模型的基础上,分别分析替打刚度、替打和锤质量比、替打环刚度对打桩系统冲击力的影响规律,表明冲击力的主要影响参数为替打刚度。

A finite element model of 3500 kJ offshore wind power pile driving system under the condition of pile rejection is established based on LS-DYNA.The internal energy transfer and the dynamic response of each component of the pile driving system is analyzed based on the stress wave principle.The lumped parameter model is established based on Newton collision theory.The model considers the mass and stiffness of each component,which is in good agreement with the analysis results of the finite element model.Based on the lumped parameter model,the influence of the stiffness of cap,the mass ratio of cap and hammer,the stiffness of ring on the impact force is analyzed.It can be found that the main parameter that affects impact force is the stiffness of cap.