基于数值试验的波浪载荷激励船舶振动响应研究  

Vibration response analysis of ships under wave load based on numerical experiment

作　　者：唐宇航[1] 陈志坚[1] 张佳栋[1] 

机构地区：[1]海军工程大学舰船工程系,武汉430033

出　　处：《振动与冲击》2016年第22期114-122,135,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(51479205)

摘　　要：即使未发生砰击振动和显著非线性波激振动,船体由较低频波浪诱导产生的振动响应中依然存在高频振动分量且高频振动衰减缓慢。从单自由度系统简谐激励振动理论入手,指出响应解析解中常被忽略的伴随自由振动项是导致高频振动的一个因素,在系统阻尼较小、自振频率较低时瞬态响应成分短时间内难以衰减,推导了位移、速度、加速度和内力响应中高频成分的占比规律。分析了波浪载荷作用于船体时"时变、场变"的性质,及船舶小阻尼系统的特点,认为伴随自由振动在波浪载荷激励振动响应预报领域中有重要地位,对比时域法和频域法在理论基础上的差异,发现了时域法在处理该问题时的优越性。通过对双体船进行数值仿真,结合海浪资料对该船16个航行工况的振动响应进行预报,结果表明各振动响应中均存在稳态高频分量且占比较高,得出了高频分量与频率比关系的规律性结论,为时域中波激振动的进一步研究提供了思路。Even if the slamming vibration and significantly nonlinear wave-induced vibration do not occur,in the vibration response of the hull induced by low-frequency wave load,there still exist high-frequency vibration components, which decay slowly.Based on the harmonic vibration analysis of single-degree of freedom system,it is indicated that the associated free vibration which is often overlooked in the analytical response solution is one of the high-frequency vibration factors.The transient response component is difficult to decay when the system damping is small and natural frequency is low.The occupied proportions of high-frequency components in the responses of displacement,velocity,acceleration and internal force were derived.The “time-changing and field-changing”characteristics of wave loads acting on ships were revealed.It is also shown that the associated free vibration plays an important role in the prediction of vibration responses excited by wave loads.The differences between the results by time domain and frequency domain methods were discussed and the advantages of time-domain methods in dealing with this issue are more prominent.The vibration responses in 16 sailing conditions were forecasted by the numerical simulation of a catamaran,using the wave data.The results show the high-frequency components in the vibration responses are both of steady-state and high-proportion.The relationship between high-frequency components and frequency ratio was obtained,which provides a guideline for the further study on wave-induced vibration in time domain.

关 键 词：伴随自由振动 动力响应 高频振动 时域法 非线性 波激振动 

分 类 号：TH212[机械工程—机械制造及自动化] TH213.3