基于数值试验的波浪载荷激励船舶振动响应研究

发布时间：2018-03-31 19:03

本文选题：伴随自由振动　切入点：动力响应　出处：《振动与冲击》2016年22期

【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。
[Abstract]:Even if there is no slamming vibration and significant nonlinear wave-induced vibration, there are still high frequency vibration components in the vibration response induced by the lower frequency wave and the attenuation of the high frequency vibration is slow.Based on the theory of harmonic excitation vibration of a single degree of freedom system, it is pointed out that the accompanying free vibration term, which is often neglected in the analytical solution of the response, is a factor leading to high frequency vibration, and the damping of the system is relatively small.It is difficult to attenuate the transient response component in a short time when the natural frequency is low. The ratio of the high frequency components in the displacement, velocity, acceleration and internal force response is deduced.The characteristics of "time-varying and field variation" of ship subjected to wave loads and the characteristics of small damped ship systems are analyzed. It is considered that accompanied by free vibration plays an important role in the field of prediction of vibration response to wave loads.By comparing the theoretical differences between the time domain method and the frequency domain method, the superiority of the time domain method in dealing with this problem is found.Based on the numerical simulation of catamaran and the wave data, the vibration response of the ship under 16 sailing conditions is predicted. The results show that there is a high frequency component in the vibration response of the catamaran.The regular conclusion of the relation between the high frequency component and the frequency ratio is obtained, which provides a train of thought for the further study of the wave-induced vibration in the time domain.
【作者单位】：海军工程大学舰船工程系;
【基金】：国家自然科学基金(51479205)
【分类号】：U661.44

【相似文献】