精细积分法在船舶桅杆涡激共振计算中的应用

Method Used to Calculate the VIV of Barrel-Shaped Mast Based on the Precise Integration Method

遵循钟万勰等发展的精细时程积分方法的基本思想,对船舶桅杆结构涡激振动响应的精细积分迭代公式进行推导,建立了外激励简化为四次多项式时的精细积分递推公式,并对两种不同表达形式的外激励简化系数进行了对比分析。应用几种数值方法对某成品油轮桅杆结构的涡激振动响应进行了数值计算。讨论了不同数值方法的计算精度及计算稳定性,绘制出桅杆结构的速度时程响应曲线和位移时程响应曲线。计算结果与实测值对比表明,外激励拓展到四次多项式时的精细积分算法与传统离散积分方法Newmark?β法和精细积分线性算法相比,具有良好的适用性,计算精度更高,计算稳定性更好。

Based on the precise integration method advanced by Prof. Zhong, the vortex-induced vibration＇s response of a barrel-shaped mast is analyzed and computed. Instead of common linear interpolation, the integration method is improved by using a 4th order polynomial approximation and the successive computation formulas are derived to calculate both velocity and displacement of the mast. Computational results show that present method is stabler and more accurate than traditional numerical methods. It has been proved that the precise integration method is feasible to analyze the vortex-induced vibration＇s response of the barrel-shaped mast.