摘要
提出了一种基于概率密度演化方法(PDEM)的结构动力可靠性分析策略,以一个特定的顶张紧式立管(TTR)为算例,计算了其随机参数激励振动响应的平均超越率,进而较为准确地评估了立管的动力可靠性.同时,还分析了立管发生参数共振时其响应概率的重尾分布特性.最后,分析了立管振动系统中的阻尼、参数激励强度和参数激励频率对立管振动响应的影响.结果表明:增大阻尼和减小参数激励强度可以起到减弱参数共振的效果,但是在设计阶段,最为有效的避免参数共振的方法是调整结构的各阶固有频率,使其远离参数激励谱峰值频率的一半;当各阶固有频率与谱峰值频率的比例不在46%〜67%范围内时,参数共振效应很弱,可以忽略不计.
The strategy based on probability density evolution method(PDEM)was put forward to calculate the probability of response and estimate the dynamic reliability in this work.The mean up-crossing rate of one particular top-tension riser(TTR)was obtained by the presented strategy,so the dynamic reliability can be estimated more accurate.Meanwhile,the fat-tail performance of the probability density was investigated.At last,the effects of damping,intensity of parametric excitation and peak frequency of parametric excitation to the response were studied.Increasing damping and lowering the intensity of parametric excitation will weaken the effect of parametric resonance.However,at design stage*the most efficient way to avoiding parametric resonance is adjusting the natural frequencies of the structure far from the half of the peak frequency of parametric excitation.This work found that if the ratios between natural frequencies and peak frequency are not in the range of 46%〜67%,the effect of parametric resonance is so weak that can be ignored.
作者
周小宇
李红霞
黄一
董磊磊
ZHOU Xiaoyu;LI Hongxia;HUANG Yi;DONG Leilei(School of Naval Architecture and Ocean Engineering,Dalian University of Technology,Dalian 116024,Liaoning China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2019年第12期104-109,共6页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51779042)
国家重点研发计划资助项目(2017YFE0111400,2018YFC0310502)
关键词
顶张紧式立管
参数振动
概率密度演化法
平均超越率
动力可靠性
top-tension riser(TTR)
parametric vibration
probability density evolution method(PDEM)
mean up-crossing rate
dynamic reliability
