大直径多筒型基础的运动特性分析

Analysis of Motion Characteristics of Multi-bucket Foundations with Large Diameter

对大直径多筒型基础通过考虑筒内气体压缩的无因次参数建立单自由度有阻尼自由振动方程,结合不同吃水下的模型试验分析筒型基础静水下的摇荡运动特性,结果表明,筒型基础结构的摇荡运动的附加质量系数都大于此前的建议值;随着吃水的增加,摇荡运动的附加质量系数都呈减小的趋势,垂荡运动的衰减系数呈增加的趋势,摇荡运动的衰减系数呈减小的趋势;相同吃水下,垂荡运动的附加质量和衰减系数小于摇摆运动的附加质量和衰减系数。

The equation of single DOF(degree of freedom)damped free vibration about bucket foundation was formulated by considering the dimensionless parameters of air compression inside the large-diameter multi-bucket foundations.The heave,roll and pitch motion characteristics of the bucket foundations under static water were studied by combining with the model tests with different drafts.The results showed that the added mass coefficients of heave,roll and pitch motion of bucket foundations are larger than the recommended value of ship dynamics;with the increase of draft,the added mass coefficients for heave,roll and pitch motion decreased,while the decay coefficient increases in heave mode and decreases in roll and pitch mode;the added mass coefficient and decay coefficient in heave direction are less than the values in roll and pitch direction.